Method and apparatus for enhanced coverage and reliability in a wireless network

Abstract

This invention describes a method and apparatus for enhanced coverage and reliability, wherein the method comprises: receiving a first message, or determining, by a first wireless device, a first configuration for accessing a first access device and / or a second access device, transmitting, by the first wireless device, to the first access device: N second messages with N equal or greater than 1, through M beams with M equal or greater than 1, and wherein the selection of N and M is according to the first configuration.

Description

[0001] Method and apparatus for enhanced coverage and reliability in a wireless network

[0002] FIELD OFTHE INVENTION

[0003] This invention relates to a method, apparatus, and system for operating a wireless device such as a user equipment to enhanced coverage and reliability in a wireless system such as a cellular system, a Wi-Fi network or the like.

[0004] BACKGROUND OF THE INVENTION

[0005] In conventional cellular networks, a primary station serves a plurality of secondary stations located within a cell served by this primary station. Wireless communication from the primary station towards each secondary station is done on downlink channels. Conversely, wireless communication from each secondary towards the primary station is done on uplink channels. The wireless communication can include data traffic (sometimes referred to User Data), and control information (also referred sometimes as signalling). This control information typically comprises information to assist the primary station and / or the secondary station to exchange data traffic (e.g. resource allocation / requests, physical transmission parameters, information on the state of the respective stations).

[0006] In the context of cellular networks as standardized by 3GPP, the primary station is referred to a base station, or a gNodeB (or gNB) in 5G (NR) or an eNodeB (or eNB) in 4G (LTE). The eNB / gNB is part of the Radio Access Network RAN, which interfaces to functions in the Core Network (CN). In the same context, the secondary station corresponds to a mobile station, or a User Equipment (or a UE) in 4G / 5G, which is a wireless client device or a specific role played by such device. The term "node" is also used to denote either a UE or a gNB / eNB.

[0007] Additionally, for example, in the case of PC5 interface or Sidelink communication, it is possible to have Direct communication between secondary stations, here UEs. It is then also possible for UEs to operate as Relays to allow for example out of coverage UEs to get an inter-mediate (or indirect) connection to the eNB or gNB. To be able to work as a relay, a UE may use discovery messages to establish new connections with other UEs.

[0008] Current wireless systems have increased requirements in reliability and coverage. For instance, to enable resilient communication in non-terrestrial networks or ensure that low power devices are capable of exchanging data.2025P00096EP03

[0009] SUMMARY OF THE INVENTION

[0010] An aim of the invention is to address above requirements and achieve increased coverage and reliability by transmitting and receiving one or more repetitive signals in one or more beams.

[0011] To this end, it is proposed in a first aspect of the invention, an apparatus for enhanced coverage, wherein the apparatus comprises:

[0012] - a transceiver,

[0013] - a processor, and

[0014] - a memory storing instructions which, when executed, cause the apparatus to - receive a first message or determine a first configuration for accessing a first access device and / or a second access device, and

[0015] - transmit to the first access device

[0016] N second messages with N equal or greater than 1,

[0017] through M beams with M equal or greater than 1, and

[0018] wherein the selection of N and M is according to the first configuration.

[0019] In accordance with a second aspect of the invention, it is proposed an apparatus for enhanced coverage, wherein the apparatus comprises:

[0020] - a transceiver,

[0021] - a processor, and

[0022] - a memory storing instructions which, when executed, cause the apparatus to - receive one or more times a second message from a first wireless device attempting to connect to the network,

[0023] - transmit L third messages with L greater or equal than 1 upon reception of one or more second messages, and

[0024] - perform or enable a data exchange with the first wireless device.

[0025] The invention is summarized by means of the methods of Claims 1-38, 40-45 the apparatuses of claims 39 and 46, and the computer program of Claim 47.

[0026] It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims or above embodiments with the respective independent claim.

[0027] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0028] BRIEF DESCRIPTION OF THE DRAWINGSIn the following drawings:

[0029] Fig. 1 schematically represents the overall cellular system including UEs, RAN, and core network;

[0030] Fig. 2 provides a schematic representation of a UE and its components; and

[0031] Fig. 3 schematically represents different entities involved in a non-terrestrial network; Fig. 4 schematically represents a random-access procedure in a wireless network; Fig. 5 schematically represents a signalling procedure by an access device;

[0032] Fig. 6 schematically represents the periodic transmission of SSB bursts;

[0033] Fig. 7 schematically represents examples of wireless devices according to some embodiments;

[0034] Fig. 8 schematically represents the distribution of a signal in a multitude of sets of communication resources according to embodiments of the invention;

[0035] Fig. 9 schematically represents the distribution of a first signal and a second signal in a multitude of sets of communication resources according to embodiments of the invention;

[0036] Fig. 10 schematically represents the distribution of a signal in a multitude of sets of communication resources and using several communication beams according to embodiments of the invention;

[0037] Fig. 11 schematically represents the distribution of a wireless sensing signal in a multitude of sets of communication resources according to embodiments of the invention;

[0038] Fig. 12 schematically represents the first, second, third, and fourth sets of communication resources as used in different embodiments of the invention;

[0039] Fig. 13 schematically represents a configuration, signal monitoring, and measurement reporting procedure according to some embodiments of the invention;

[0040] Fig. 14 schematically represents a message flow according to some embodiments of the invention;

[0041] Fig. 15 schematically represents the distribution of signals through several beams; Fig. 16 schematically represents the distribution of a signal in a multitude of sets of communication resources and using several communication beams according to embodiments of the invention;

[0042] Fig. 17 schematically represents the selection of beams for the distribution of a signal through several beams based on the moving direction of the wireless device; and

[0043] Fig. 18 schematically represents the selection of beams for the distribution of a signal according to embodiments of the invention;

[0044] Fig. 19, Fig. 20, and Fig. 22 schematically illustrate QPSK encoding schemes; andFig. 21 and Fig. 23 schematically illustrate the PAPR performance achieved by some of the embodiments in the invention;

[0045] Fig. 24 schematically illustrates the PAPR achieved in a 16-QAM scheme using a variable number of repetitions showing that for two repetitions the improvement is of around 3 dB.

[0046] DETAILED DESCRIPTION OF EMBODIMENTS

[0047] Embodiments of the present invention are now described based on a cellular communication network environment, such as 5G or 6G. However, the present invention may also be used in connection with other wireless technologies.

[0048] Throughout the present disclosure, the abbreviation "gNB" (5G terminology) or " BS" (base station) or the term "access device" is intended to mean a wireless access device such as a cellular base station or a Wi-Fi access point or a ultrawide band (UWB) personal area network (PAN) coordinator. The gNB may consist of a centralized control plane unit (gNB-CU-CP), multiple centralized user plane units (gNB-CU-UPs) and / or multiple distributed units (gNB-DUs). The gNB is part of a radio access network (RAN), which provides an interface to functions in the core network (CN). The RAN is part of a wireless communication network. It implements a radio access technology (RAT). Conceptually, it resides between a communication device such as a mobile phone, a computer, or any remotely controlled machine and provides connection with its CN. The CN is the communication network's core part, which offers numerous services to customers who are interconnected via the RAN. More specifically, it directs communication streams over the communication network and possibly other networks.

[0049] Furthermore, the terms "base station" (BS) and "network" may be used as synonyms in this disclosure. This means for example that when it is written that the "network" performs a certain operation it may be performed by a CN function of a wireless communication network, or by one or more base stations that are part of such a wireless communication network, and vice versa. It can also mean that part of the functionality is performed by a CN function of the wireless communication network and part of the functionality by the base station.

[0050] It is further noted that throughout the present disclosure only those blocks, components and / or devices that are relevant are shown in the accompanying drawings. Other blocks have been omitted for reasons of brevity. Furthermore, blocks designated by same reference numbers are intended to have the same or at least a similar function, so that their function is not described again later.A cellular system is a wireless communication system that consists of three main components: user equipment (UE), radio access network (RAN), and core network (CN). These components work together to provide voice and data services to mobile users over a large geographic area.

[0051] In conventional cellular networks, a primary station serves a plurality of secondary stations located within a cell served by this primary station. Wireless communication from the primary station towards each secondary station is done on downlink channels. Conversely, wireless communication from each secondary towards the primary station is done on uplink channels. The wireless communication can include data traffic (sometimes referred to User Data), and control information (also referred sometimes as signalling). This control information typically comprises information to assist the primary station and / or the secondary station to exchange data traffic (e.g. resource allocation / requests, physical transmission parameters, information on the state of the respective stations). In the context of cellular networks as standardized by 3GPP, the primary station is referred to a base station, or a gNodeB (or gNB) in 5G (NR) or an eNodeB (or eNB) in 4G (LTE). The eNB / gNB is part of the Radio Access Network RAN, which interfaces to functions in the Core Network (CN). In the same context, the secondary station corresponds to a mobile station, or a User Equipment (or a UE) in 4G / 5G, which is a wireless client device or a specific role played by such device. The term "node" is also used to denote either a UE or a gNB / eNB.

[0052] Additionally, for example, in the case of PC5 interface or Sidelink communication, it is possible to have Direct communication between secondary stations, here UEs. It is then also possible for UEs to operate as Relays to allow for example out of coverage UEs to get an inter-mediate (or indirect) connection to the eNB or gNB. To be able to work as a relay, a UE may use discovery messages to establish new connections with other UEs. Certain UEs may communicate with each other by using device-to-device communication, also known as sidelink communication using the PC5 interface that may rely on physical sidelink (PS) broadcast channel, PS shared channel, PS control, etc. Furthermore, the role of a relay node has been introduced in 3GPP. This relay node is a wireless communication station that includes functionalities for relaying communication between a primary station, e.g. a gNB and a secondary station, e.g. a UE. This relay function for example allows to extend the coverage of a cell to an out-of-coverage (OoC) secondary station. This relay node may be a mobile station or could be a different type of device. In the specifications for 4G, the Proximity Services (ProSe) functions are defined inter alia in TS 23.303, and TS 24.334 to enable - amongst others -connectivity for the cellular User Equipment (UE) that is temporarily not in coverage of the cellular network base station (eNB) serving the cell. This particular function is called ProSe UE-to-network relay, or Relay UE for short. The Relay UE relays application and network traffic in two directions between the OoC UE and the eNB.The local communication between the Relay UE and the OoC UE is called device-to-device (D2D) communication or Sidelink (also known as PC5) communication in TS 23.303 and TS 24.334. Once the relaying relation is established, the OoC-UE is, e.g., IP-connected via the Relay UE and acts in a role of " Remote UE". This situation means the Remote UE has an indirect network connection to selected functions of the Core Network as opposed to a direct network connection to all Core Network functions that is the normal case. Furthermore, it has been introduced the role of a UE-to-UE relay node, i.e., a relay node re-laying the communication between two UE devices. The relay node relays the communications between UE devices. UEs may connect to the core network through a base station when in-coverage. In such relay scenarios, the relay devices may receive and store some information for some time before forwarding it towards the target device. This information that may be stored and forwarded may be discovery messages received from a source UE whereby the relay UE may release them at some point of time later. This information that may be stored and forwarded may be a SIB that may contain a timestamp.

[0053] User equipment (UE) is the device that a user uses to access the cellular system, such as a smartphone, a tablet, a laptop, loT device, or a wearable device. A UE typically may contain the following components:

[0054] - A universal integrated circuit card (UICC), which stores the user's identification and authentication information, such as the subscription permanent identifier (SUPI) or credentials.

[0055] - A transceiver, which converts the digital signals from the processor into analog signals for transmission and reception over the air interface. The transceiver also performs modulation, demodulation, coding, decoding, and other signal processing functions.

[0056] - A processor, which controls the operation of the UE and executes the applications and services that the user requests. The processor also communicates with the RAN and the CN using various protocols.

[0057] - A display, which shows the user the information and feedback from the UE, such as the signal strength, the battery level, the call status, the messages, the contacts, the menu, etc.

[0058] - A microphone and a speaker, which enable the user to make and receive voice calls, as well as use other audio features, such as voice mail, voice recognition, etc.

[0059] - A keyboard and / or a touch screen, which allow the user to enter and select commands, text, numbers, etc.

[0060] - A camera and / or a video recorder, which enable the user to capture and send images and videos, as well as use other multimedia features, such as video calling, video streaming, etc.- A memory, which stores the data and programs that the user needs, such as the phone book, the messages, the photos, the videos, the applications, etc as well as a computer program to perform the operations of the RAN and CN protocols.

[0061] - A battery, which provides the power supply for the UE.

[0062] Fig. 2 provides a schematic representation of a UE and its components, e.g., UICC (201), processor (202), transceiver (203), memory (204), input devices (205) such as camera, microphone, etc and output devices (206) such as display, speaker, etc. Fig. 7 schematically represents wireless devices that may include the capabilities of a UE and / or a STA. Fig. 7a) represents AR / VR glasses; Fig. 7b) represents a connected vehicle; and Fig. 7c) represents a mobile phone. In these devices, a reflective intelligent surface (RIS) may be embedded, e.g., by covering and / or under the whole a part of the UE surface. This may be used, e.g., to better deal with interferences or improve wireless sensing.

[0063] A UE may access the cellular network via the radio access network, as described below. Certain UEs may communicate with each other by using device-to-device communication, also known as sidelink communication using the PC5 interface that may rely on physical sidelink (PS) broadcast channel, PS shared channel, PS control channel, etc.

[0064] A UE may receive a configuration by means of different procedures:

[0065] Downlink control information (DCI) is a type of control information that is sent from the BS to the UE on the physical downlink control channel (PDCCH). DCI contains various parameters that instruct the UE how / when to decode and transmit data on the physical downlink shared channel (PDSCH) and the physical uplink shared channel (PUSCH), such as the resource allocation, the modulation and coding scheme. The UE needs to monitor the PDCCH in each subframe to detect and decode the DCI that is addressed to it.

[0066] Uplink control information (UCI) is a type of control information that is sent from the UE to the BS on the physical uplink control channel (PUCCH) or the physical uplink shared channel (PUSCH). UCI contains various feedback signals that inform the BS about the status and quality of the downlink transmission, such as the HARQ. acknowledgments (ACKs), the channel state information (CSI), and the scheduling requests (SRs). The UE needs to encode and transmit the UCI according to the configuration and timing indicated by the BS.

[0067] Sidelink control information (SCI) is a type of control information that is sent from the UE to another UE on the physical sidelink control channel (PSCCH) in device-to-device (D2D) communication scenarios. The main functions of SCI include resource allocation, synchronization, channel quality reporting,.2025P00096EP03

[0068] Medium access control (MAC) control element (MAC CE) is a type of control information that is sent from the BS to the UE or vice versa on the MAC layer. MAC CE contains various commands or indications that regulate the MAC layer functions, such as the buffer status report (BSR), the timing advance command (TAC), the discontinuous reception (DRX) command, etc. The UE needs to process the MAC CE according to the MAC protocol and the configuration provided by the BS.

[0069] Radio resource control (RRC) command is a type of control information that is exchanged between the BS and the UE on the RRC layer. RRC Command contains various messages that modify / configure RRC parameters and / or initiate, modify, or release the RRC connection or the radio bearers between the UE and the BS, such as the RRC connection setup, the RRC connection reconfiguration, the RRC connection release, the security mode command, the mobility from E-UTRA command, the handover from E-UTRA preparation request, etc. The UE needs to respond to the RRC Command according to the RRC protocol and the configuration provided by the BS.

[0070] Non-access stratum (NAS) messages are used for signalling between UE and core network (CN) on the non-access stratum (NAS) layer. NAS messages enable functionality such as registration, session establishment, security, and mobility management. The UE needs to respond to the NAS Command according to the NAS protocol and the configuration provided by the CN.

[0071] UE parameter update (UPU) is a procedure between the UE and the home network that enables the home network to update configuration parameters in mobile phones and / or USIM using the UDM control plane procedure (TS 23.502). The UE can receive Parameters Update Data from the UDM after the UE has registered in the 5G network.

[0072] Steering of Roaming (SoR) enables the home network to guide the user equipment (UE) when registering on a visited network. For detailed information about the interfaces and registration in the 5G System, refer to 3GPP TS.23.501 (Release 15) and 3GPP TS 24.501 (Release 15). The 5G CP-SOR is activated during or after registration to update the UE's " Operator Controlled PLMN Selector with Access Technology" list via secure NAS messages, as directed by the home PLMN based on specific operator policies, such as preferred networks or UE location.

[0073] UE configuration update (UCU) is used to update configuration parameters as perTS 23.502 that may include Access and Mobility Management related parameters decided and provided by the AMF, UE Policy provided by the PCF. When AMF wants to change the UE configuration for access and mobility management related parameters the AMF initiates the procedure defined in clause 4.2.4.2. When the PCF wants to change or provide new UE Policies in the UE, the PCF initiates the procedure defined in clause 4.2.4.3. If the UE Configuration Update procedure requires the UE to initiate a Registration procedure, the AMF indicates this to the UE explicitly. The procedure in clause4.2.4.2 may be triggered also when the AAA Server that performed Network Slice-Specific Authentication and Authorization for an S-NSSAI revokes the authorization.

[0074] Radio access network (RAN) is the part of the cellular system that connects the UEs to the CN via the air interface. The RAN consists of base stations (BSs). A base station (BS) is a fixed or mobile transceiver that covers a certain geographic area, called a cell. In 5G, a BS is also called a gNB (next generation node B). A BS can serve multiple UEs simultaneously within its cell, by using different frequencies, time slots, codes, or beams. A BS also performs functions such as power control, handover control, channel allocation, interference management, etc. A base station can be divided into two units: a central unit (CU) and a distributed unit (DU). The CU performs the higher layer functions, such as RLC, PDCP, RRC, etc. The DU performs the lower layer functions, such as PHY and MAC. The CU and the DU can be co-located or separated, depending on the network architecture and deployment. In cellular systems, a base station may be denoted, based on context, as a cell, or gNB.

[0075] The cell may also refer to the coverage area of a base station. A BS may have different coverage areas such as a macro cell (e.g. several kilometres wide), a pico cell (e.g., for a given location such as a stadium) or a femto cell for a small location (e.g., a home or part of it).

[0076] A base station may communicate with the core network. Since there can be base stations for different cellular systems, different interfaces are required. For instance, a base station, eNB, in a 4G Long Term Evolution (LTE) system (also known as Evolved Universal Mobile Telecommunications Systems (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the 4G CN known as EPC through the corresponding interface. For instance, a base station, gNB, in a 5G system (i.e., 5G New Radio or Next Generation RAN) may communicate with the 5GC through a different interface. 4G and 5G base stations may communicate with each other directly or through their corresponding core networks.

[0077] The main protocols used between the UEs and the RAN are:

[0078] - The physical layer (PHY), which defines the characteristics of the air interface, such as the frequency bands, the modulation schemes, the coding rates, the frame structure, the synchronization, etc.

[0079] -The medium access control (MAC) layer, which regulates the access of the UEs to the shared radio channel, by using techniques such as orthogonal frequency division multiple access (OFDMA), time division duplex (TDD), frequency division duplex (FDD), etc.

[0080] - The radio link control (RLC) layer, which provides reliable data transmission over the radio channel, by using techniques such as segmentation, reassembly, error detection, error correction, retransmission, etc.2025P00096EP03

[0081] - The packet data convergence protocol (PDCP) layer, which compresses and decompresses the headers of the data packets, encrypts and decrypts the data, and performs data integrity protection.

[0082] - The radio resource control (RRC) layer, which establishes, maintains, and releases the radio bearers between the UEs and the RAN, as well as exchanges the signalling messages for functions such as connection setup, handover, measurement reporting, security activation, etc.

[0083] A transmission / reception communication unit or transceiver may be used by BS and UE to transmit / receive data. Control data may be required for a physical broadcast channel, physical downlink control channel, etc. Data may be for the physical downlink shared channel.

[0084] Data may be encoded by the UE and / or BS to obtain data symbols and / or control symbols that may be exchanged over the wireless interface. The conversion from digital data into analog symbols may be done by the transmission / reception communication unit

[0085] A medium access control control-element (MAC-CE) is a MAC layer communication element that is used to control the communication between wireless devices. A MAC-CE may be exchanged in a shared channel, e.g., the physical downlink / uplink / sidelink shared channel.

[0086] The communication between a UE and a base station or the communication between UEs (when sidelink is used) may involve the exchange of reference signals. Reference signals may include primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel demodulation reference signal (DMRS), a channel state information reference signal (CSI-RS). Core network (CN) is the part of the cellular system that connects the RAN to other networks, such as the Internet, or other cellular systems. The CN consists of two main (control / user) domains. The control domain is responsible for providing signalling and control functions for the UEs, such as authentication, authorization, mobility management, session management, etc. The control plane consists of several network functions (NFs), such as the access and mobility management function (AMF), the session management function (SMF), the unified data management (UDM), the policy control function (PCF), the network exposure function (NEF), and the authentication server function (AUSF). The access and mobility management function (AMF) is a NF that handles the registration, deregistration, connection management, and mobility management for the UEs. The session management function (SMF) is a NF that handles the establishment, modification, and release of the sessions for the UEs. The SMF also communicates with the user plane devices to perform functions such as IP address allocation, tunnelling, QoS, etc. The unified data management (UDM) is a NF that stores and manages the user data, such as the SUPI, the service profile, the subscription status, etc. The policy control function (PCF) is a NF that provides the policy rules and charging information for the UEs, such as the access type, the service level, the data rate, the quota, etc. The2025P00096EP03

[0087] network exposure function (NEF) is a NF that exposes the network capabilities and services to external applications and devices, such as the IMS, the Internet of Things (loT), etc. The authentication server function (AUSF) is a NF that performs the primary authentication with the by using credentials and the SUPI. The user domain is responsible for providing data and multimedia services to the UEs, by using packets and IP addresses. The user plane consists of two main functions: the user plane function (UPF) and the data network (DN). The user plane function (UPF) is a device that forwards the data packets between the UEs and the DNs, as well as performs functions such as tunnelling, firewall, QoS, charging, etc. The data network (DN) is a network that provides access to the services and applications that the UEs request, such as the Internet, the IMS, etc.

[0088] A residential gateway (RG) is a device that connects a home network to an external network, such as the Internet or a cellular system. An RG typically provides functions such as routing, switching, firewall, NAT, DHCP, DNS, VPN, etc. An RG can also support various types of interfaces, such as Ethernet, Wi-Fi, Bluetooth, USB, etc. A cellular-capable RG is an RG that has a cellular interface, such as a UICC slot, a cellular modem, or an antenna, that enables it to access the cellular system as a backup or an alternative to the wired or wireless broadband connection. A cellular-capable RG can provide benefits such as: (1) Enhanced reliability, by switching to the cellular connection in case of a failure or a degradation of the broadband connection; (2) Increased bandwidth, by aggregating the cellular connection and the broadband connection to achieve higher data rates or QoS.

[0089] A multi-SIM subscription is a subscription that allows a user to have multiple SIMs (or eSIMs) that are linked to the same account and service profile. A user can use the multi-SIM subscription to access the cellular system from different devices, such as a smartphone, a tablet, a laptop, or a wearable device, without having to switch the SIM card or the device.

[0090] Overall system: Fig. 1 provides an overall description of a wireless system wherein devices 100, 102, and 128 can play the role of UEs. Device 102 is part of a cellular-capable RG providing connectivity to a home network 129 e.g., by means of a local area network and / or wireless local area network. Device 102 is served by base station 104.

[0091] The RAN 127 comprises base station 103 and serves UE 128. UE 128 may also be a UE to Network relay given access to remote UE 136 that is out of coverage of base station 103. UEs 134 and 136 also communicate with each other via a UE-to-UE relay 135. UE to UE communication via relays is enabled by means of sidelink communication / PC5 interface.

[0092] Within the RAN, the range of base station 103 is extended via smart repeater 137 and reflective intelligent surface (RIS) 138. Smart repeater 137 and RIS 138 give access to UE 142.The RAN 143 includes base station 104 tand serves as wireless access infrastructure for the home network. Base station 104 also serves a mobile access device and / or UE as a UAV 139. UAV 139 may provide connectivity to remote UE 136.

[0093] Furthermore, a satellite gateway 141 is shown that connects to satellite 140 and may provide connectivity services to remote UE 136 or UE 100.

[0094] In Fig. 1, the 5G core network 133 may include one or more an AMF 121, SMF 123, UPF 122, AUSF 124, UDM 125, PCF 131, NEF 132 and allows the connection to a data network 130.

[0095] In Fig. 1, a second core network 142, e.g., a legacy core network as a 4G core network, is also shown that may interface with the 5G core network 133, interface with base stations denoted eNB in 4G, and provide a connection to the data network 130. The legacy 4G core network is denoted EPC and may include one or more mobility management entities (MME), a serving gateway, a multimedia broadcast multicast service gateway, a broadcast multicast service center, a packet data network gateway, etc. The mobility management entity may handle the signalling between UE and the 4G CN and may interact with the home subscriber server (HSS) in charge of the storage and management of subscriber data and secrets. The MME may provide connection management, similar to the AMF in 5G. The serving gateway may be used to exchange user internet protocol messages whereby the serving gateway may interact with the packet data network gateway that is connected to IP services. Multiple protocols in 4G and 5G have similar features. For example, the 5G network registration and 4G attach registration message are initially sent by the UE to establish a connection between the UE and the CN, which involves sending an initial request from the UE with its identity and capabilities, receiving an authentication request from the CN with a challenge, sending an authentication response from the UE with a response, receiving an authentication result from the CN with an indication of success or failure, and sending a security mode command from the CN with the selected security algorithms. As a result of this connection establishment procedure, NAS and AS keys are derived from the K_AMF (5G) and K_ASME (4G) where K_AMF is managed by the AMF and K_ASME is managed by the MME. A UE may connect to a serving network or serving Public Land Mobile Network (PLMN). A UE may have a subscription with a home PLMN, and during the registration procedure, the (AMF of the) serving PLMN may forward the registration request to the (AUSF of the) home PLMN that may perform an initial authentication procedure between home PLMN and UE. If the authentication procedure is successful, keys are derived and the home PLMN may share derived credentials with the serving PLMN, including K_SEAF, that may be used to derive K_AMF, from which NAS keys and AS keys are derived. The registration request sent by the UE includes an identifier that can be used by the home PLMN to identify the UE. To prevent privacy vulnerabilities, the long-term subscriber's identifier known as Subscriber Permanent Identifier (SUPI) may not be exchanged in the clear, but instead,2025P00096EP03

[0096] either a Subscription Concealed Identifier (SUCI) or a pseudonym known as GUTI are exchanged with the AMF of the serving PLMN. The AMF of the PLMN may then forward the SUCI to the home PLMN so that the home PLMN decrypts / verifies it.

[0097] Satellite access: Fig. 1 depicts satellite 140 providing access to one or more UEs. Satellite access can be performed by means of non-terrestrial devices at different altitudes such as Low Earth Orbit (LEO), Medium Earth Orbit (MEO) or Geosynchronous Equatorial Orbit (GEO) satellites. Other types of non-terrestrial devices may include high-altitude platform station (HAPS) or unmanned aerial vehicle (UAVs) that may comprise a base station. Fig. 3 illustrates different elements including a GEO satellite 302, a MEO satellite 303, LEO satellites 304 and 304', a UAV 305, all of them potential non-terrestrial mobile access devices giving coverage to wireless device (e.g., a UE) 301. GEO satellite 302 remains static over a given earth position while MEO and LEO satellites move. MEO satellite 303 has a slower moving vector 306 in relation to the earth compared with LEO satellites 304 / 304' that have a faster moving vector 307 / 307'. A non-terrestrial gateway 308 is included that provides connectivity to the mobile access device via a feeder link 310. A mobile access device provides service to the wireless device via a service link 311. Two mobile access devices in the same orbit may communicate with each other via an intra-orbit-satellite link 312 while two mobile access devices in different orbits may communicate with each other via an inter-orbit-satellite link 313. Fig. 3 finally also includes a terrestrial access device 309 that may also provide connectivity to wireless device 301. The terrestrial access device 309, the wireless device 301, and non-terrestrial gateway are on the earth surface 314.

[0098] Non-terrestrial devices such as satellites distribute system information in specificSIBs, in particular, SIB31 in 4G and SIB19 in 5G. SIB19 information element as defined in TS 38.331 18.2.0. — ASN1START

[0099] — TAG-SIB19-START

[0100] SIB19-rl7::= SEQUENCE {

[0101] ntn-Conf ig-r 17 NTN-Config-rl7

[0102] OPTIONAL, — Need R

[0103] t-Service-rl7 INTEGER ( 0..549755813887 )

[0104] OPTIONAL, — Need R

[0105] referenceLocation-rl7 Ref erenceLocat ion-r 17

[0106] OPTIONAL, — Need R

[0107] distanceThresh-rl7 INTEGER ( 0.. 65525 )

[0108] OPTIONAL, — Need R

[0109] ntn-NeighCellConf igList-r 17 NTN-NeighCellConf igList-r 17

[0110] OPTIONAL, — Need R

[0111] lateNonCritical Extension OCTET STRING

[0112] OPTIONAL,

[0113] [ [

[0114] ntn-NeighCellConfigListExt-vl720 NTN-NeighCellConf igList-r 17

[0115] OPTIONAL — Need R

[0116] ] J,

[0117] [ [

[0118] movingRef erenceLocation-r 18 ReferenceLocation-rl7

[0119] OPTIONAL, — Need R2025P00096EP03

[0120] ntnCovEnh-r 18 NTN-CovEnh-rl8

[0121] OPTIONAL, — Need R

[0122] satSwitchWithReSync-r 18 Sat SwitchWithReSync-r 18

[0123] OPTIONAL — Need R

[0124] ] ]

[0125] }

[0126] NTN-NeighCellConfigList-rl7:: = SEQUENCE ( SIZE ( 1..maxCellNTN-rl7 ) ) OF NTN- NeighCellConf ig-rl7

[0127] NTN-NeighCellConfig-rl7:: = SEQUENCE {

[0128] ntn-Conf ig-r 17 NTN-Config-rl7

[0129] OPTIONAL, — Need R

[0130] carrierFreq-r 17 ARFCN-ValueNR

[0131] OPTIONAL, — Need R

[0132] physCellId-rl7 PhysCellld

[0133] OPTIONAL — Need R

[0134] }

[0135] NTN-CovEnh-rl8:: = SEQUENCE {

[0136] number Of Msg4HARQ-ACK-Repetitions-r 18 BI T STRING ( SI ZE ( 4 ) ),

[0137] rsrp-ThresholdMsg4HARQ-ACK-r 18 RSRP-Range

[0138] OPTIONAL — Need R

[0139] }

[0140] SatSwitchWithReSync-rl8:: = SEQUENCE {

[0141] ntn-Conf ig-r 18 NTN-Conf ig-r 17,

[0142] t - Service St ar t-r 18 INTEGER ( 0..549755813887 )

[0143] OPTIONAL, — Need R

[0144] ssb-TimeOf f set-r 18 INTEGER ( 0.. 159 )

[0145] OPTIONAL — Need R

[0146] }

[0147] — TAG-SIB19-STOP

[0148] — ASN1STOP

[0149] SIB19 field descriptions

[0150] distanceThresh

[0151] Distance from the serving cell reference location and is used in location-based measurement initiation in RRCJDLE and RRCJNACTIVE, as defined in TS 38.304

[0020] , Each step represents 50m. This field is only present in an NTN cell.

[0152] movingReferenceLocation

[0153] Reference location of the serving cell of an NTN Earth-moving cell at a time reference. It is used in the evaluation of eventD2 and condEventD2 criteria for the serving cell in RRC_CONNECTED, and locationbased measurement initiation in RRCJDLE and RRCJNACTIVE when distanceThresh is also configured, as defined in TS 38.304

[0020] , The time reference of this field is indicated by epochTime in ntn-Config of the serving cell. This field is excluded when determining changes in system information, i.e., changes to movingReferenceLocation should neither result in system information change notifications nor in a modification of valueTag in SIB1. This field is only present in an NTN cell.

[0154] ntn-Config

[0155] Provides parameters needed for the UE to access NR via NTN access such as Ephemeris data, common TA parameters, k_offset, validity duration for UL sync information and epoch. In a TN cell, this field is only present in ntn-NeighCellConfigList and ntn-NeighCellConfigListExt.

[0156] ntn-NeighCellConfigList, ntn-NeighCellConfigListExt

[0157] Provides a list of NTN neighbour cells including their ntn-Config, carrier frequency and PhysCellld. This set includes all elements of ntn-NeighCellConfigList and all elements of ntn-NeighCellConfigListExt. If ntn-Config is absent for an entry in ntn-NeighCellConfigListExt, the ntn-Config provided in the entry at the same position in ntn-NeighCellConfigList applies. Network provides ntn-Config for the first entry of ntn-NeighCellConfigList. If the ntn-Config is absent for any other entry in ntn-NeighCellConfigList, the ntn-Config provided in the previous entry in ntn-NeighCellConfigList applies.

[0158] referenceLocation

[0159] Reference location of the serving cell provided via NTN (quasi)-Earth fixed cell and is used in location-based measurement initiation in RRCJDLE and RRCJNACTIVE, as defined in TS 38.304

[0020] , This field is only present in an NTN cell.

[0160] satS witch With ReSync

[0161] Provides parameters for the target satellite required to perform satellite switch with resynchronization. This field is only present in an NTN cell and its presence indicates that satellite switch without PCI change is supported in the cell.

[0162] t-Service

[0163]

[0164] 2025P00096EP03

[0165] Indicates the time information on when a cell provided via NTN is going to stop serving the area it is currently covering. This field applies for both service link switches in NTN quasi-Earth fixed cell and feeder link switches for both NTN quasi-Earth fixed and Earth-moving cell. The field indicates a time in multiples of 10 ms after 00:00:00 on Gregorian calendar date 1 January, 1900 (midnight between Sunday, December 31, 1899 and Monday, January 1, 1900). The exact stop time is between the time indicated by the value of this field minus 1 and the time indicated by the value of this field. The reference point for t-Service is the uplink time

[0166]

[0167] synchronization reference point of the cell. This field is only present in an NTN cell.

[0168] NTN-CovEnh field descriptions

[0169] numberOfMsg4HARQ-ACK-Repetitions

[0170] The number of repetition slots for PUCCH transmission with HARQ-ACK information for Msg4, see clause 9.2.6 in TS 38.213

[0013] , The first / leftmost bit corresponds to the repetition factor 1, the second bit corresponds to repetition factor 2, the third bit corresponds to the repetition factor 4, and the last / rightmost bit corresponds to the repetition factor 8. The repetition factor 1 shall be indicated together with at least one other repetition factor. _

[0171] rsrp-ThresholdMsg4HARQ-ACK

[0172] This threshold is used by the UE for determining the configuration of the MAC entity for PUCCH repetition for

[0173]

[0174] Msg4 HARQ-ACK, as specified in clause 6.2.1 in TS 38.321 [3].

[0175] SatSwitchWithReSync field descriptions

[0176] ssb-TlmeOffset

[0177] Indicates the time offset between the SSB from source and target satellite at the uplink time synchronization reference point. It is given in number of subframes.

[0178] t-ServiceStart

[0179] Indicates the time information on when the target satellite is going to start serving the area currently covered by the serving satellite. The field indicates a time in multiples of 10 ms after 00:00:00 on Gregorian calendar date 1stJanuary 1900 (midnight between Sunday, December 31, 1899, and Monday, January 1, 1900). The exact start time is between the time indicated by the value of this field minus 1 and the time indicated by the value of this field. The reference point for t-ServiceStart is the uplink time synchronization reference point of

[0180]

[0181] the serving satellite.

[0182] A UE in a cellular system performs an initial random-access procedure to connect an access device. The 5G random access procedure is illustrated by means of Fig. 4 wherein 401 represents a user equipment and 402 represents an access device. The access device distributes signals 402. Signals 402 can be distributed periodically or on demand. Signals 402 may comprise the Master Information Block (MIB) transmitted together with / in the physical broadcast channel (PBCH) and the synchronization signals. The MIB comprises:

[0183] MIB::= SEQUENCE {

[0184] systemFrameNumber BIT STRING (SIZE (6)), subCarrierSpacingCommon ENUMERATED {scsl5or60, scs30orl20} ssb-SubcarrierOffset INTEGER (0..15),

[0185] dmrs-TypeA-Position ENUMERATED {pos2, pos3},

[0186] pdcch-ConfigSIBl INTEGER (0..255),

[0187] cellBarred ENUMERATED {barred, notBarred},

[0188] intra Freq Reselection ENUMERATED {allowed, notAllowed}, spare BIT STRING (SIZE (1))

[0189] }MIB and PBCH are transmitted as part of a Synchronization Signal Block, and the access device may transmit multiple SSBs through different beams, allowing the user equipment to determine the preferred beam, and once the preferred beam is obtained, retrieve the MIB, and use the information in the MIB to attempt to retrieve System Information Block 1 (SIB1) that may also be distributed periodically. The UE can use the information in SIB1 to perform the random-access procedure selecting a preamble to indicate its intention to access the cell by means of message 404, e.g., preamble transmission. This message maybe used to derive a random-access radio network temporary identifier (RA-RNTI). Upon reception of message 404, access device 402 replies with message 405, e.g., a random access response. This message may include a time advance field to adapt the transmission timing, a value matching the preamble used by wireless device 401, and a grant (communication resources) for the wireless device. The access device also assigns a temporary cell radio network temporary identifier (TC-RNTI). Prior to this message 405, the access device may send a PDCCH DCI message assigning resources (a communication grant). This message may be addressed using the RA-RNTI. Upon reception of message 405, wireless device uses the initial grant received in the previous message and the RA-RNTI to transmit a subsequent message 406, e.g, an RRCSetupRequest or PHY layer. This message may include a Contention Resolution Identifier (CRI). This message may be sent in the PUSCH. As a response, access device replies with message 407, e.g., RRCSetup, that includes / repeats the received CRI confirming that the access device has identified the access device. This message includes a Cell RNTI (C-RNTI). Next, wireless device replies with message 408, e.g., an RRCSetupComplete that includes the RegistrationRequest message, and UE capabilities.

[0190] MIB and PBCH are transmitted as part of a Synchronization Signal Block, and the access device may transmit multiple SSBs through different beams. Multiple SSBs transmitted through multiple beams form an SSB burst. The multiple SSBs in an SSB burst are transmitted sequentially in the first part of a frame. SSB bursts are transmitted periodically, typically every 20 ms, or more.

[0191] Fig. 5 schematically illustrates an access device 500 transmitting four beams, each of them transmitting an SSB, namely 501, 502, 503, and 504. A wireless device 505 can measure the signal strength, i.e., RSRP (Reference Signal Received Power), of the beams. This is illustrated by means of the graph in Fig. 5 where 501', 502', 503', and 504' represent the RSRP of beams 501, 502, 503, and 504, respectively, as measured by wireless device 505. Wireless device 505 can use this information to determine which one of the beams is the preferred beam for further communication, e.g., to perform the random access procedure.2025P00096EP03

[0192] Fig. 6 further schematically illustrates SSB bursts transmitted periodically. In this case, each SSB burst comprises four SSBs transmitted in the first part / half of every second frame. In this figure, frames are denoted as f, f+1, f+2, f+3,... A frame has a typical duration of 10 ms.

[0193] Resource grid: in a cellular network, such as a 5G network, the resource grid is a structured framework used to allocate and manage communication resources efficiently. It is characterized by a time-frequency matrix where each element, known as a resource element, is defined by its position in both time and frequency domains. The vertical axis represents frequency, segmented into subcarriers, which are spaced at intervals. The subcarrier spacing can vary depending on the deployment scenario, with common spacings being 15 kHz, 30 kHz, 60 kHz, 120 kHz, 240 kHz, and 480 kHz (corresponding to mu equal to 0, 1, 2, 3, 4, and 5, respectively). The horizontal axis of the grid represents time and is divided into frames, subframes, and slots, each frame has a duration of 10 ms and each subframe has a duration of 1 millisecond. Within these subframes, the time is further divided into slots. For mu, there are 2μmu slots per subframe. Each slot typically spans 14 OFDM symbols. Each resource element in the grid, defined by the intersection of a time symbol and a frequency subcarrier, can carry a small portion of data, control information, or reference signals. These resource elements are grouped into larger units called Resource Blocks (RBs), which span 12 subcarriers in frequency and one slot in time. The allocation of these RBs is dynamically managed.

[0194] Reflective intelligent surfaces (RIS): may be used as part of the wireless infrastructure or as part of the wireless devices. RIS, often referred to as metasurfaces, are advanced materials engineered with sub-wavelength structures that can manipulate electromagnetic waves in a controlled manner. These surfaces consist of an array of unit cells, each capable of adjusting its electromagnetic response through electronic control, thus enabling dynamic alteration of the wavefront of the incident signal. The wireless device can utilize the RIS to fine-tune the reflection properties of the wireless sensing signal, such as phase, amplitude, and polarization. By dynamically adjusting these parameters, the RIS can enhance signal strength, directivity, and overall signal quality. For instance, the RIS can focus the reflected signal towards the transmitter, significantly improving signal reception. This capability is particularly advantageous in urban environments where obstacles and interference are prevalent. Technical details of the RIS involve the implementation of tunable elements, such as varactor diodes or microelectromechanical systems (MEMS), in each unit cell. These elements allow real-time reconfiguration of the surface's electromagnetic properties in response to control signals from the wireless device. The control signals can be generated based on real-time analysis of the received signal's quality and contextual parameters, ensuring optimal reflection under2025P00096EP03

[0195] varying conditions. The RIS can operate in various frequency bands, including sub-6 GHz and millimeter-wave (mmWave) frequencies, making it versatile for different wireless applications. Additionally, the RIS can incorporate sensing capabilities to monitor the environment and further refine the reflection parameters. For example, integrated sensors can detect changes in temperature, humidity, or the presence of obstacles, and adjust the reflection properties accordingly to maintain high signal quality.

[0196] Quality of Service: a wireless system may be used to transport data belonging to different types of applications such as Machine Type Communication (MTC), Critical Machine Type Communication (CMTC), Enhanced Mobile Broadband (EMB), or Fixed Wireless Access (FWA). MTC (e.g., smart meters, tracking,...) requires low bandwidth and non-latency critical, CMTC (e.g., industrial applications) has strict throughput, latency, and availability needs, EMB (VR / AR, 4K UDH,...) and FWA (e.g., in the home) require high data rate, with low latency, and low end-to-end response time. In wireless network such as 5G the Quality of Service has to accommodate different applications such as EMB, MTC, ultra-reliable low latency communications. QoS is influenced by the entities involved in the communication, UE, RAN, UPF, and DN. Data exchanges between UE and DN are mapped to QoS flows, and each QoS flow is mapped to a 5G QoS Identifier (5QI) in TS 23.501 (Table 5.7.4-1) that describes resource types, priority, packet delay budget, packet error rate, maximum data burst volume. Network is configured to configure RAN and core network interfaces to achieve the requirements of a 5QI. QoS is applied to a data stream from the wireless physical layer to the core network. Between RAN and UPF, QoS is applied in terms of a QoS flow. QoS in the RAN is managed by means of Data Radio Bearers (DRB). A QoS flow on core network side is created by means of a PDU session establishment accept. The mapping between a QoS flow and a DRB is done by means of SDAP configuration in an RRC message (RRCSetup or RRCReconfiguration) The indication or identifier that connects the whole QoS pipe is called QoS flow identifier. Downlink traffic requires mapping IP messages and the QoS pipe, and this is done by the UPF. For each IP message or packet, the UPF checks (by means of a packet QoS assignment / detection rule) the packet information (source / destination / protocol / type of service / ...) and directs the IP packet to a QoS flow. The packet QoS assignment / detection rule is provided by SMF interacting with PCF. In the uplink, the UE performs a similar task by applying QoS rules provided in NAS messages (e.g., PDU session establishment) by the SMF or are pre-configured / derived by the UE.

[0197] Discontinuous reception (DRX) in cellular networks such as 5G is in two types, Idle mode DRX and Connected mode DRX. In Idle mode DRX, the UE wakes up to monitor for paging2025P00096EP03

[0198] messages. If no paging message is detected, it sleeps further. In Connected DRX mode, the UE enters in sleep mode periodically and during the sleep period the UE is not required to monitor the Physical Download Control Channel. The access device configures the UE device with C-DRX parameters. Connected DRX approach reduces energy consumption of the device because it does not require monitoring the PDCCH periodically and it also reduces the transmissions of CSI or SRS signals, that also has a positive effect in the network / access devices load. There are two types of DRX cycles, long and short. A long DRX cycle consists of an on period and an off period. The on duration is in terms of milliseconds. The long DRC cycle may be configured or the long DRX cycle and short DRX cycles may be configured. The access device can configure the time (drx-onDurationTimer) during which the UE is awake and goes back to sleep if there is no PDCCH received. The access device can also configure a given drx-LongCycleStartOffisetto start to awake period ata subframe boundary and / or drx-SlotOffset relative to the subframe boundary. If there is activity in an awake period, the UE may remain awake some more time determined by the drx-lnactivityTimer. Furthermore, the access device can configure long DRX cycle together with additional DRX cycle which is shorter than long DRX cycle. Configurable parameters include the drx-ShortCycle (duration of the short cycle) and drx-ShortCycleTImer that determines how many short cycles before the device should apply.

[0199] Data scheduling in a cellular network such as a 5G cellular network may be performed by means of a scheduler wherein the scheduler takes as input information such as measurements of UE / network, buffer status report, QoS requirements, associated radio bearers, or a scheduling request. In the downlink, data scheduling may be performed by means of dynamic scheduling and semi persistent scheduling (SPS). In dynamic scheduling, every data exchange in the Physical Downlink Shared Channel (PDSCH) is scheduled by means of a downlink control information (DCI) message in the Physical Downlink Control Channel (PDCCH). In SPS, the scheduling is done by means of an RRC message. In the uplink, scheduling can be performed by means of dynamic scheduling and configured scheduling (CS). In dynamic scheduling each Physical Uplink Shared Channel (PUSCH) is scheduled over DCI. In CS, the PUSCH transmission is scheduled via RRC message. Furthermore, a Scheduling Request message may be sent over the PUCCH (Physical Uplink Control Channel) or in an Uplink Control Information (UCI) in the PUSCH (Physical Uplink Shared Channel). An SR may be sent by a UE device when it has data to transmit. Upon reception, the access device can allocate resources (Uplink Grant by means of the Physical Downlink Control Channel. Upon resource allocation, the UE device can transmit data in the Physical Uplink Shared Channel.

[0200] Wireless sensing and integrated wireless sensing and communication: wireless systems are evolving to include wireless sensing capabilities. These wireless sensing capabilities may be implemented e.g. by a radar functionality in wireless communication involving one or more access2025P00096EP03

[0201] devices (e.g., base stations (BS)) and / or one or more terminal devices (e.g., UEs). As an example, Frequency Modulated Continuous Wave (FMCW) mmWave radar systems can measure range, velocity, and angle of arrival (if two receivers are available) of objects in the scene which reflect radio waves. Such radar systems emit a chirp signal, e.g., a sine wave that increases in frequency over time. The chirp signal (e.g., a continuous wave pulse) has a bandwidth and a frequency increase rate. Generally, a continuous series of such chirps are emitted. The transmitted and received analogue chirp signals are mixed to generate an intermediate frequency (IF) signal which corresponds to the difference in frequencies of the two signals (outbound and inbound) and whose output phase corresponds to the difference in the phases of the two signals. Each surface of a scene or environment will therefore produce a constant frequency IF signal whose frequency relates to the distance to the surface (i.e., a first distance from the transmitter of the chirp signal to the surface plus a second distance from the surface to the receiver of the chirp signal). To resolve two surfaces at different distances, the two IF signals can be frequency resolved. A longer time window of the IF signal results in greater resolution. As the chirp time is related to its bandwidth (with constant chirp frequency change) the resolution of the radar is related to the chirp bandwidth. The IF signal may then be band pass filtered (to remove signals below some minimal range and frequencies above the maximum frequency for a subsequent analogue-to-digital converter (ADC)) and digitized prior to further processing. The upper frequency sensing range of the bandpass filter and ADC sets the maximum range that can be detected (i.e., IF frequencies increase with range). To detect vibrations, the phase of the IF signal is important, since the phase (i.e., the difference in phases of the transmitted and received chirp signals) is a sensitive measure of small changes in the distance of a surface. Small distance changes can be detected in the phase signal but may be indiscernible in the frequency signal. Moreover, phase difference measures between two consecutive chirp signals can be used to determine the velocity of the surface. As an example, a fast Fourier transform (FFT) processing can be performed across multiple chirp signals to enable separation of objects with the same range but moving at different velocities. A Fourier transform converts a signal from a space or time domain into the frequency domain. In the frequency domain the signal is represented by a weighted sum of sine and cosine waves. A discrete digital signal with N samples can be represented exactly by a sum of N waves. FFT provides a faster way of computing a discrete Fourier transform by using the symmetry and repetition of waves to combine samples and reuse partial results. This method can save a huge amount of processing time, especially with real-world signals that can have many thousands or even millions of samples. As a further example, angle estimation can be performed by using the phase difference between the received chirp signal at two separated receivers.2025P00096EP03

[0202] As another option, a channel state information (CSI) can be used, which is a measure of the phases and amplitudes of many frequencies detected at a receiver, thereby forming a complex 'map' of the radio environment, including effects of objects within that environment. CSI characterizes how wireless signals propagate from the transmitter to the receiver at certain carrier frequencies. CSI amplitude and phase are impacted by multi-path effects including amplitude attenuation and phase shift, e.g., by the displacements and movements of the transmitter, receiver, and surrounding objects and humans. In other words, CSI captures the wireless characteristics of the nearby environment. These characteristics, assisted by mathematical modeling or machine learning algorithms, can be used for different sensing applications. A radio channel may be divided into multiple subcarriers, as is done e.g. in 5G communication systems (using e.g. orthogonal frequency division multiplexing (OFDM)). To measure CSI, the transmitter may send long training symbols (LTFs), which contain pre-defined symbols for each subcarrier, e.g., in a packet preamble. When those LTFs are received, the receiver can estimate a CSI matrix using the received signals and the original LTFs. For each subcarrier, the channel can be modeled by y = Hx + n, where y is the received signal, x is the transmitted signal, H is the CSI matrix, and n is the noise vector. The receiver estimates the CSI matrix / / using a pre-defined signal x and the received signal y after signal processing such as removing cyclic prefix, de-mapping and demodulation. The estimated CSI is then a three-dimensional matrix of complex values and this matrix represents an 'image' of the radio environment at that time. By processing a time series of such 'images' information on movements, locations and vibrations of objects can be extracted. Such a processing of a CSI matrix can be used for vital signs monitoring, presence detection, and human movement recognition. As an example, neural network like recognition techniques can be used to process the CSI matrix to perform such kinds of recognition.

[0203] It is noted that systems using channel state information (CSI) are somehow related to systems with FMCW mmWave radar. In a CSI-based system, the input signal X may be defined and the receiver may use the received signal Y to obtain H, i.e., as H = (Y ) / X. In a FMCW mmWave radar, the transmitted signal Chirp X may also be predefined, and the receiver may uses the received signal Y to obtain a transfer function as H = Y / X. This last step is in fact somehow related to multiplying the locally computed chirp signal and the received chirp signal and applying a bandpass filter. According to various embodiments in this invention, the above-described wireless sensing techniques are implemented in a mobile communication system (e.g. 5G or 6G or other cellular or WiFi communication systems), while the functional coexistence of radar and communication operating in the same frequency bands is configured to avoid interference bandwidths. Thereby, radio sensing can be integrated into large-scale mobile networks to create perceptive mobile networks.As another example, the sensing signal may consist of a number of pulses sent, e.g., at specific frequencies and timing (sensing signal parameter information) by a sensing transmitter. The sensing receiver may include a number of bandpass filters that allow identifying the sensing signal parameter information, e.g., timing and frequency of the received pulses. In particular, if the transmitter determines a given pseudo-random sequence of frequency / timing pulses and beams it, e.g., by means of beamforming, in a specific direction, and if the transmitter communicates to the receiver the timing / frequency, in general, the sensing signal parameter information, of the transmitted sensing signal, the receiver can use its bandpass filters to identify the reception of the same transmitted pulses, i.e., sensing signal, based on the received sensing signal parameter information.

[0204] The wireless sensing signal may be part of the synchronization signal block. For instance, the wireless sensing signal may be a reference signal included in the primary synchronization signal or in the secondary synchronization signal. It may consist of a number of reference signals and / or it may be a wide band signal. This wireless sensing signal can allow the access devices to determine the presence of a wireless device. The wireless device may also use this wireless sensing signal to determine the access device that is more suitable to (re-)select.

[0205] Wireless local area network technologies such as Wi-Fi allow devices to connect to the Internet or to each other without using cables. Wi-Fi is based on radio waves that are transmitted and received by a device called a wireless access point (AP). The AP acts as a hub that connects WiFi enabled devices, such as laptops, smartphones, tablets, smart TVs, etc., to a wired network, such as a local area network (LAN) or the Internet.

[0206] The term Wi-Fi is a trademark of the Wi-Fi Alliance, an industry association that certifies products that comply with the IEEE 802.11 standards for wireless local area networks (WLANs). These standards define the physical and data link layers of the communication protocol, such as the frequency bands, modulation schemes, encryption methods, authentication mechanisms, and data rates used by Wi-Fi devices. The most common Wi-Fi standards are 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, and 802.11ax, which operate in different frequency bands (2.4 GHz, 5 GHz, or both) and offer different levels of performance and compatibility.

[0207] To use Wi-Fi, a device needs to have a wireless network interface card (NIC) that can send and receive radio signals. The NIC scans the available wireless channels and detects the presence of nearby APs. The device then selects an AP to connect to, based on factors such as signal strength, security settings, and network name (SSID). The device and the AP exchange information, such as the MAC address, IP address, encryption key, and password, to establish a connection. This process is2025P00096EP03

[0208] called association. After the connection is established, the device can communicate with the AP and other devices on the same network, or access the Internet through the AP.

[0209] IEEE 802.11n (Wi-Fi 4) provided new features such as MIMO and frame aggregation to increase throughput. IEEE 802.11ac (Wi-Fi 5) introduced wider bandwidth and MU-MIMO. IEEE 802.11ax (Wi-Fi-6) included OFDMA and BSS color or spatial reuse to use spectrum resources more efficiently. IEEE 802.11ah introduced target wake time (TWT) to support low power loT applications by allowing STAs to go into sleep when not in a wake period after negotiation with AP. IEEE 802.11be (Wi-Fi 7) aims at improving throughput and latency operating in unlicensed bands between 1GHz and 7.125 GHz. Wi-Fi 7 increases bandwidths up to 320 MHz, 4096 QAM modulation, and supporting up to 16 spatial streams in MU-MIMO with an improved sounding procedure. Wi-FI 7 also enables multiple resource units to be assigned to a single device. Furthermore, it includes an enhanced preamble with a universal SIG filed indicating the PHY version. It also extends the negotiated ack buffer size to 1024 bits. It also enables multilink operation (MLO) enabling multiple links between a station and an access point, for instance an AP can have two radios 2.4 and 5 GHz and use both of them for simultaneous transmission and / or reception with a multi-link capable device (MLD) capable station. Wi-Fi 7 also includes a restricted TWT providing predictable latency by assigning STAs to different rTWT types and making sure that other STAs do not transmit if they do not belong to a given rTWT type. Wi-Fi 7 also include multi-AP coordination performing, e.g., coordinated transmission, beamforming, or joint transmission.

[0210] For instance, in references to Fig. 1, devices 100, 101 and 102 can be Wi-FI access points and device 106 can be a wireless station. Station 106 and access point 101 are MLD and communicate with two links 126. Device 102 is a cellular capable residential gateway.

[0211] Section: efficient transmission and reception of a signal

[0212] Some techniques in this disclosure are illustrated in the context of the efficient and reliable transmission and reception of a signal. Signals may be transmitted for multiple purposes, e.g., to wake up a device, to synchronize a device, to provide a pilot signal / reference signal for channel state measurement and / or channel estimation for demodulation, to indicate the device about the reception of data, to perform wireless sensing. In all those cases, it is of paramount importance to perform the measurement of the signal in a reliable and (energy) efficient manner. To this end:

[0213] In embodiment for energy-efficient and reliable reception of a signal or a signal measurement in a wireless system, a first wireless device, which may be a User Equipment (UE) or a station (STA), may receive a configuration of a set of communication resources (e.g., a set ofcommunication resources may refer to one or more first bandwidth parts / frequency ranges to be monitored during one or more time intervals) to be monitored from a second wireless device. The second wireless device, which may be an access point (AP) or a base station (BS), may transmit the signal once or multiple times. When multiple times, it should be at least two transmissions. The first wireless device may determine or receive a configuration that specifies how to monitor (e.g., a mode of monitoring) the set of communication resources to obtain the signal measurement. The first wireless device may then obtain the measurement of the signal. As described in other embodiments, the measurement of the signal may refer to measurements of the signal such as signal strength, etc. or to the reception of a message included / encoded in the signal. This embodiment can be combined with other embodiments or used independently.

[0214] It is to be noted that some embodiments of this invention may be described, e.g., in the context of a wireless procedure such as initial access, e.g., initial access by transmitting preambles through one or more beams to one or more access devices. In this context, the transmission of preambles (also denoted as second messages in some embodiments) may be subject to repetition, and, e.g., the repetition of those preambles, RAR, etc may be benefit of embodiments related to the energy-efficient and reliable reception of a signal.

[0215] It is to be noted that the mode of monitoring may refer to the process to receive the signal / perform the signal measurement. For instance, in some embodiments of the disclosure the mode of monitoring may refer to the process in which certain signals are monitored or not monitored. For example, the mode of monitoring may specify whether the wireless device may monitor all repetitions of a signal or only a subset of them, such as the first M repetitions out of N, or a subset identified by means of a bitmap or codebook. The mode of monitoring may further define whether the monitoring follows a sequential approach— where the wireless device continues to monitor communication resources until a decoding criterion is met— or an alternating approach— where different communication resources, beams, or frequency ranges are monitored in an interleaved manner to mitigate interference or improve robustness. In some examples, the mode of monitoring may indicate that monitoring of subsequent communication occasions is conditional, e.g., only performed if the measurement quality in a first communication occasion does not meet a minimum threshold or if certain message parts (e.g., a preamble) can be decoded correctly. The mode of monitoring may also determine how measurement results are combined across multiple communication resources, for example by maximum-ratio combining of analog samples, majority voting of decoded messages, selection of the strongest received instance, or early termination of monitoring once a valid signal is obtained. Additionally, the mode of monitoring may define which communication parameters— such as SNR, RSSI, error vector magnitude, or CRC results— areevaluated to decide whether additional communication resources need to be monitored. The mode of monitoring may be determined by means of the first configuration, that may be, e.g., received, or retrieved from memory, etc.

[0216] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may use the information in all communication resources in a / the first set of communication resources to receive the signal, e.g., by combining (adding the received signals) to reduce the noise, e.g., by maximum ratio combining, e.g., by only decoding the message / signal in the resource with the highest signal strength (e.g., when resources are in different beams), e.g., by decoding the messages in each of the measured signals, followed by majority voting, i.e., selecting the most frequent decoding result, by selecting the first signal whose CRC is verified correctly, etc. When combining the analog signals, the output of the antenna may be passed to a cascade of delay circuits. When the signal is repeated M times, the first received signal goes through M-l delay circuits, the second received signal through M-2 circuits and so on. The output of the delay circuits and the output of the antenna can be "combined" in this manner.

[0217] In a related embodiment that may be combined with other embodiments or used independently, the second wireless device may be a UE / STA that may have been configured by a third access device (e.g., a primary base station) with communication resources to transmit a signal once or multiple times. The second wireless device may then transmit the signal in those communication resources, and the signal transmitted in those resources may be received by the first access device (e.g., secondary base station) that may determine or receive a configuration specifying how to monitor the set of communication resources. This embodiment may be advantageous when transmitting a wake-up signal to first access device, i.e., secondary base station.

[0218] In some cases, the third access device may be a source access device, and the first access device may be a target access device, e.g., during a handover procedure.

[0219] In some cases, the third access device may be a primary access device, and the first access device may be a secondary access device, e.g., during a dual connectivity procedure.

[0220] In some cases, the third access device may be a first transmission and reception point and the first access device may be a second transmission and reception point, e.g., in a cell-free system, and the wake-up signal may be transmitted to wake up the second transmission and reception point.In an embodiment that may be combined with other embodiments or used independently, the signal may be transmitted multiple times in a set of communication resources. The wireless device, which may be a User Equipment (UE) or a station (STA), may receive this signal from another wireless device, which may be an access point (AP) or a base station (BS). The signal may be transmitted in several messages where:

[0221] - each message may comprise the exact same signal to ensure redundancy and increase the probability of successful reception.

[0222] - each message may comprise the exact same signal subject to a transformation, e.g., a cyclic bit shift, to ensure redundancy and increase the probability of successful reception.

[0223] - each message may include the exact signal as payload but with a different header to differentiate between transmissions and facilitate error detection and correction.

[0224] - each message may include the exact signal as payload but with a different header, wherein some of the fields may be transmitted implicitly.

[0225] - the signal may include a Cyclic Redundancy Check (CRC) for error-checking purposes. - each message may incorporate a message-specific CRC to further enhance error detection capabilities.

[0226] - the signal and / or message may include a preamble and / or postamble.

[0227] - messages may be transmitted according to a regular pattern of communication occasions (e.g., random access occasions), which helps synchronization and efficient resource allocation.

[0228] - the communication occasions may be scheduled in a manner that allows the first wireless device to reliably detect and decode at least one transmission of the signal.

[0229] In a related embodiment that may be combined with other embodiments or used independently, the transmitted signal may refer to one or more of:

[0230] - a wake-up signal transmitted to a wireless device,

[0231] - preambles transmitted during random access,

[0232] - preambles transmitted to wake up an access device,

[0233] - reference signals such as a positioning or wireless sensing signal,

[0234] - DCI messages,

[0235] - UCI messages,

[0236] In a related embodiment that may be combined with other embodiments or used independently, the second wireless device may transmit multiple signals, e.g., a first signal and asecond signal, each signal once or multiple times, e.g., at least Ml times the first signal and at least M2 times the second signal. The first wireless device may also be interested in monitoring the first signal and the second signal. The wireless device may determine or receive a configuration specifying how to monitor (monitoring mode) the communication resources allocated to the transmission of the first signal and second signal so that the first signal and second signal can be determined / obtained, e.g., in the best possible manner. In particular, repetitions of the first and second signals may be monitored in different manners:

[0237] - Alternatingly i.e. the monitoring of the first and second signals is interleaved. This may be preferred to reduce the chances of being subject to interferences,

[0238] - Sequentially, i.e., monitor first the first signal till reception and then monitor the second signal till reception.

[0239] Alternatively or sequentially may refer to the monitoring of time resources, frequency resources, beam resources, code resources, etc. as per other embodiments.

[0240] For instance, the first signal may be, e.g., a low power synchronization signal or a wake up signal, and the second signal may be, e.g., a normal synchronization signal or a paging message, etc.

[0241] In another embodiment that may be combined with other embodiments or used independently, the first set of communication resources may comprise communication resources used by the second wireless device to transmit the signal in at least a first communication occasion, and the communication resources of at least a reference communication occasion may use a communication configuration different than the communication configuration of the first communication occasion. The reference communication occasion may be, e.g., a guard-band.

[0242] This can allow the receiving device to determine whether a signal is present in the at least first communication occasion or not, e.g., by comparing the signal / measurement in the at least first communication occasion with the measurement in the reference communication occasion.

[0243] In another embodiment that may be combined with other embodiments or used independently, the first set of communication resources may comprise communication resources used by a wireless device that may be an access point (AP) or a base station ( BS) to transmit the signal in at least a first communication occasion, and the communication resources used for at least a reference communication occasion may use a communication configuration different than the communication configuration of the first communication occasion. The reference communication occasion may be used to transmit a reference message using a specific (reference) communication configuration. The communication configuration may refer to various parameters such as the type of signal transmitted,2025P00096EP03

[0244] the signal strength, modulation and coding schemes, frequency bands, pre-coding matrix, beams, and time division duplexing (TDD) configurations.

[0245] In another embodiment that may be combined with other embodiments or used independently, the wireless device may monitor and compare the communication configurations estimated and / or measured in, e.g., the first and reference communication occasions. For example, the wireless device may compare at least one measured communication parameter of the first communication occasion with at least one measured communication parameter in the reference communication occasion. These communication parameters may include signal-to-noise ratio (SNR), received signal strength indicator (RSSI), or error vector magnitude (EVM).

[0246] In an example, the comparison may be performed between different parts of the communication occasions. The wireless device may compare at least one measured communication parameter of a first part in the first communication occasion with a corresponding measured communication parameter of a second part in the same occasion. For instance, the device may measure and compare the preamble, or a part of the preamble, and the payload signal quality.

[0247] In another example, the wireless device may compare at least one measured communication parameter of a first message part transmitted in the first communication occasion with a second message part within the same occasion. The message parts may include different segments of a data packet where each segment may carry different levels of importance or redundancy.

[0248] In an example, the wireless device may also compare the measured communication parameter of the first communication occasion with a configured threshold value. The threshold value may be a numerical value representing a specific signal quality / quantity metric that must be met or exceeded for successful communication, e.g., signal strength, signal quality, error rate, etc. This ensures that the wireless device maintains a reliable connection even in varying network conditions.

[0249] In an example, the embodiment may include determining that at least a first message part transmitted in the first communication occasion can be decoded correctly, e.g., the preamble. This determination may involve complex signal processing techniques such as sequence matching, error detection and correction algorithms, which may use CRCs or other error-checking methods.In an embodiment that may be combined with other embodiments or used independently, the first set of communication resources may comprise communication resources used by a wireless device that may be an access point (AP) or a base station ( BS) to transmit the signal at least in a first communication occasion and in a second communication occasion. The first configuration may require monitoring the second communication occasion if a wireless device that may be a User Equipment (UE) or a station (STA) determines the presence of the transmission of the signal in the first communication occasion and the measurement of the signal does not achieve a minimum quality.

[0250] This embodiment may include the optional step of evaluating one or more communication parameters, such as signal-to-noise ratio (SNR) or received signal strength indicator (RSSI), in the first communication occasion before deciding to monitor the second communication occasion. Additionally, the wireless device may be configured to use advanced signal processing techniques such as error vector magnitude (EVM) analysis to determine signal quality. If the signal quality in the first communication occasion is below the configured threshold value, the wireless device may then proceed to monitor the second communication occasion to ensure a reliable connection. This can allow reducing the energy consumption of the receiver since a receiver may only need to monitor the second communication occasion when the reception was not sufficient, e.g., better than a threshold.

[0251] In an embodiment that may be combined with other embodiments or used independently, the wireless device that may be a User Equipment (UE) or a station (STA) may undertake one or more of the following actions:

[0252] - receive a second set of communication resources and a third set of communication resources to monitor: The second and third sets of communication resources may be subsets of the first set of communication resources. This can include or refer to frequency bands, time slots, and spatial channels that the wireless device, i.e., UE or STA, needs to monitor. By receiving these resources, the device can ensure it has all the necessary information to maintain a robust connection and optimize its performance in varying network conditions, thereby enhancing overall communication reliability. - obtain a second intermediate signal measurement by monitoring the second set of communication resources: This step may involve gathering detailed metrics such as signal strength, signal-to-noise ratio (SNR), error vector magnitude (EVM), and other relevant parameters. These measurements are crucial for understanding the quality of the signal received from the second set of communication resources. Accurate signal measurement allows the device to make informed decisions about future communication strategies, leading to improved signal integrity and reduced transmission errors.2025P00096EP03

[0253] - determine or receive a second configuration comprising criteria to evaluate the second intermediate signal measurements: The second configuration may include specific threshold values for various signal quality metrics, such as minimum acceptable SNR or maximum allowable error rates. By evaluating these criteria, the device can decide whether it needs to monitor the third set of communication resources. This evaluation process ensures that the device only engages in further monitoring when necessary, conserving resources and enhancing efficiency. For instance, the device may only monitor the third set of communication resources if it has a clear indication that a signal is being transmitted in the second set of communication resources. For instance, the device may only monitor the third set of communication resources if it cannot receive the signal properly based on the second intermediate signal measurement.

[0254] - monitor the third set of communication resources to obtain third intermediate signal measurements: If the criteria of the second configuration are met, the device may proceed to monitor the third set of communication resources. This monitoring may involve advanced techniques such as cross-band and temporal analysis, which help in understanding the signal quality across different dimensions and / or set of communication resources. The data from the second and third intermediate signal measurements can be combined to form a comprehensive assessment of the signal, e.g., to reduce the signal to noise ratio. Combination may be done by adding all or part of the measurements, e.g., those parts carrying the same signal. This thorough monitoring ensures that the device can maintain high-quality communication links, adapt to changing conditions, and minimize the likelihood of connection drops.

[0255] In a related embodiment that may be combined with other embodiments or used independently, the first configuration and / or the second configuration comprise one or more of: - Communication resources used by the first, second, or third set of communication resources, - Condition to monitor the signal M times, with M less or equal than N, and which signal / occasions should be monitored. This condition may specify how often the signal should be monitored, the frequency of monitoring the signal to ensure it meets the required quality standards. For example, if M is set to 3, the device will monitor the signal three times within a specified period to gather enough data for accurate quality assessment. For instance, if a signal is repeated N = 8 times, the wireless device may be instructed to monitor the signal M = 4 times that may correspond to the first 4 signal repetitions, or alternating signal repetitions, e.g., 1, 3, 5, 7, or a subset of them. Which signal repetitions need to be monitored may be signaled by means of a codebook, or by means of a bitmap. By setting M < N, where N is a predefined maximum value, the system ensures that resources are not overutilized, thereby maintaining efficiency while guaranteeing reliable communication.It is to be noted that in some embodiments of this invention, the first configuration may refer specifically to the set of resources that require monitoring (e.g., as in previous embodiment) and / or the mode of monitoring. In some embodiments, it may refer to the configuration required to perform a wireless procedure (e.g., random access) over multiple beams.

[0256] In a related embodiment that may be combined with other embodiments or used independently, the communication resources may include various types of resources required for signal transmission and reception. For example,

[0257] - Time resources: Specific time slots allocated for transmitting or receiving data to avoid collisions and ensure synchronization in a time-division multiplexing system.

[0258] - Frequency resources: Distinct frequency bands assigned to different communication signals to minimize interference and maximize bandwidth in frequency-division multiplexing systems.

[0259] - Code resources: Unique codes used in code-division multiple access (CDMA) to differentiate between multiple signals sharing the same frequency band.

[0260] - Spatial resources: Different spatial paths utilized in multiple-input multiple-output (MIMO) systems to increase data throughput and reliability.

[0261] - Beam resources: Directional beams formed using advanced antenna techniques to enhance signal strength and reduce interference in beamforming technologies.

[0262] - 0AM mode: Orbital Angular Momentum modes used in advanced communication systems to encode additional information by manipulating the phase of electromagnetic waves.

[0263] - Time resources: In time-division multiplexing (TDM), time slots are allocated to different users or data streams. Each slot represents a specific duration during which the user or data stream has exclusive access to the communication channel. This allocation helps avoid data collisions and ensures that all users or streams can transmit their data without interference.

[0264] - Frequency resources: In frequency-division multiplexing (FDM), the available bandwidth is divided into multiple frequency bands, each assigned to a different communication signal. This division allows multiple signals to coexist on the same communication medium without interfering with each other, thus optimizing the use of available bandwidth.

[0265] - Code resources: In code-division multiple access (CDMA), each user is assigned a unique code sequence that modulates their signal. These codes are orthogonal, meaning that they do not interfere with each other, allowing multiple users to share the same frequency band simultaneously. The receiver uses the same code to demodulate the signal, separating it from other signals.

[0266] - Spatial resources: In multiple-input multiple-output (MIMO) systems, multiple antennas are used at both the transmitter and receiver ends. These antennas create multiple spatial paths for the signal,increasing the data throughput and reliability of the communication link. By exploiting the spatial diversity, MIMO systems can achieve higher data rates and better performance in challenging environments.

[0267] - Beam resources: Beamforming is a technique used in advanced antenna systems to focus the signal in a specific direction. By controlling the phase and amplitude of the signal at each antenna element, the system can create a directional beam that enhances the signal strength and reduces interference from other sources. This technique is particularly useful in dense urban environments and for long-range communications.

[0268] - 0AM mode: Orbital Angular Momentum (0AM) modes involve manipulating the phase of electromagnetic waves to create helical wavefronts. These wavefronts carry additional information, allowing for higher data rates and more efficient use of the communication spectrum. 0AM modes are being explored for various applications, including high-capacity wireless communications and optical fiber networks.

[0269] In a related embodiment that may be combined with other embodiments or used independently, a wireless device, e.g., a UE, may be configured (e.g., by an access device) with communication resources determining when / how a signal is transmitted through at least two beams. The wireless device may then receive the signal, e.g., a wake-up signal (WUS) and / or synchronization signal, through the two or more beams. Allocated communication resources in different beams may have different periodicity, this may allow reducing the energy consumption on the device since it may need to monitor less communication resources, while still allowing to monitor multiple beams. The wireless device may use signals measurements obtained from / through both beams to receive / obtain the signal. The wireless device may perform measurements of the signal, e.g., WUS, to determine the preferred beam. The wireless device may report the measurements and / or preferred beam. The wireless device may use the preferred beam to contact the network, e.g., an access device. The network may use the preferred beam to distribute another type of signal, e.g., wake up signal. The measurements that are transmitted may be compressed, e.g., if a signal is repeated 4 times, the absolute value of the first measurement (e.g., signal strength) is transmitted and for the remaining 3 measurements, only the differential value is transmitted.

[0270] Some embodiments are illustrated by means of Fig. 13 that represents the signaling between a first wireless device 1300 and a second wireless device 1301. Not all the steps may be required. Steps maybe repeated and may also be executed in different order. In step 1302, the second wireless device 1301 may provide the first wireless device with a configuration of the first set ofcommunication resources. In step 1303, the second wireless device 1301 may provide the first wireless device 1300 with a first configuration containing the monitoring mode and / or the first wireless device may determine such a first configuration. In step 1304, the second wireless device may distribute signals according to a fourth set of communication resources comprising the first set of communication resources configured in the first wireless device. The first wireless device may perform monitoring activities to obtain measurements of the transmitted signal as described in other embodiments. In step 1305, the first wireless device may report measurements to the second wireless device.

[0271] Fig. 12 schematically represents the first, second, third, and fourth set of communication resources. The fourth set of communication resources 1200 comprises the first set of communication resources 1201. The first set of communication resources comprises the second set of communication resources 1202 and the third set of communication resources 1203.

[0272] Some embodiments are illustrated by means of Fig. 10 wherein the time distribution of signals is illustrated through a first, second, and third beam. The signals distributed through each beam are indicated as 1000, 1001, and 1002, respectively. The signals 1001 transmitted through a second beam are distributed with a higher frequency / shorter period than signals 1000 and 1002 distributed through a first and third beams. The timing of the signals in different beams may be aligned so that a wireless device may monitor multiple signals transmitted through multiple beams. For instance, the six signals within the dashed square 1003 are time aligned so that communication resources used to transmit signals do not overlap. The timing of the communication resources used to transmit a signal through the same beam may depend on the number of beams also transmitting the same signal. For instance, signals 1001' transmitted through the second beam when the first / third beams do not transmit any signals are repeated faster (communication resources are allocated shortly after each other) compared with signals 1001 transmitted through the second beam when the first / third beams do transmit signals 1000 and 1002, respectively.

[0273] In a related embodiment that may be combined with other embodiments or used independently, the reference communication occasion, which may be adjacent to, e.g., the first communication occasion (i.e., in resources such as time resources or frequency resources that are next to the resources of the first communication occasion), or at a known position, e.g., relative to, e.g., the first communication occasion, or a part of the first communication occasion or a part of the message transmitted in the first communication occasion, first set of communication resources, etc, may need to be configured. This configuration ensures that the reference communication occasion is2025P00096EP03

[0274] optimally scheduled and aligned with the overall communication strategy. The configuration process may involve defining specific time slots, frequency bands, message parts, or code sequences that the reference communication occasion will use. These parameters are typically determined based on the network requirements, the quality of service (QoS) criteria, and the specific application needs. The configuration may be done by means of a configuration message (e.g., RRC message). The configuration may be done using absolute values or relative to the first communication occasion. The reference communication occasion can be a dedicated time slot within a time-division multiplexing (TDM) framework, a particular frequency band in a frequency-division multiplexing (FDM) system, or a unique code in a code-division multiple access (CDMA) environment. The goal is to allocate these resources in a way that maximizes efficiency and reliability while minimizing interference and ensuring seamless integration with other communication occasions.

[0275] In a related embodiment that may be combined with other embodiments or used independently, the first wireless device, e.g., a UE or STA, may transmit to the second wireless device measurements and / or selected parameters used by the first wireless device to monitor the first set of communication resources when obtaining the measurement of the signal. This embodiment is advantageous because it may allow the second wireless device to select more suitable parameters for the first wireless device, e.g., in a subsequent communication round.

[0276] In a related embodiment that may be combined with other embodiments or used independently, a second wireless device such as a base station or an access point, may transmit a configuration of a first set of communication resources to monitor by a first wireless device such as a UE or STA, where the first set of communication resources may be transmitted within a fourth set of communication sources used by a wireless device to transmit the signal two or more times; and transmit, a first configuration determining how the first wireless device (e.g., UE / STA) may monitor the first set of communication resources to obtain the measurement of the signal.

[0277] In a related embodiment that may be combined with other embodiments or used independently, the signal may be a reference signal, e.g., synchronization signals, and the measurement of the signal is the measurement of the reference signal. The reference signal may be transmitted multiple N times and a wireless device may be provided with a configuration to monitor all N times or a subset of M of these times, depending on its capabilities. A wireless device may determine based on the configurations whether it is required to monitor all M reference signals or only a subset.2025P00096EP03

[0278] In a related embodiment that may be combined with other embodiments or used independently, a signal such as a wake up signal or a low power synchronization signal may contain an identifier, e.g., a group identifier. The group identifier may be used to wake-up multiple wireless devices simultaneously, e.g., when multiple wireless devices are supposed to receive a common signal, e.g., a broadcast message, e.g., a SIB, e.g., an emergency message, a public warning system (PWS) message or an ETWS (Earthquake and Tsunami Warning System), or a CMAS (Commercial Mobile Alert System) message.

[0279] In a related embodiment that may be combined with other embodiments or used independently, a wake-up signal may be transmitted, e.g., prior to a paging occasion. A group identifier may be determined according to the location, e.g., area that needs to receive the wake-up signal. The identifier itself may relate to the geographic location that requires receiving the wake-up signal, e.g., it may be the center of a circle (determined by the latitude and longitude) and the radius of the circle. Any wireless device within the area may be required to wake up. This approach may allow, e.g., for the specific distribution of emergency messages without requiring the preconfiguration of many groups and this may be more specific than using a common WUS group to wake up all wireless devices monitoring the same WUS / communication resources. This approach may be more accurate. For instance, all or a subset of UEs may be required to monitor some communication resources, e.g., WUS resource, and react when they determine that their / its location falls within the area determined by the group ID transmitted in the communication resource, where the group ID encoded in the transmitted signal represents / encodes / indicates the area. Since this approach may allow addressing / waking up millions of devices simultaneously, devices may be configured to not accept certain group IDs, e.g., group IDs encoding an area larger than a threshold. Additionally or alternatively, wireless devices may be configured with communication resources, e.g., WUS resources, to monitor and identifiers according to the area where they were located. Wireless devices in that area may then wake up when such a WUS is received and may monitor a subsequent message, e.g., the paging message. The paging message may indicate the type of emergency message and may include information about the area that is affected. The paging message may include information to receive the emergency message directly without requiring the acquisition of SI Bl. Wireless devices accepting the paging message may then receive the emergency message that may further specify which devices are affected.2025P00096EP03

[0280] In an embodiment that may be combined with other embodiments or used independently, a (group) wake up signal ((G)WUS) may be used not only in the most recent cell where the wireless device went into inactive / idle state but also in other cells. For instance, if a wireless device goes in inactive / idle state when boarding a boat and going towards the sea, and then an emergency happens, the wireless device may not be able to receive an emergency message. Thus, wake up signals may also need to be monitored from other cells, e.g., NTN cells. For instance, the wireless device may receive a message, e.g., an RRCConnectionRelease, indicating the communication resources, e.g., WUS parameters, it has to monitor. This may be beneficial because a wireless device in inactive / idle mode may not be able to connect to a cell first to obtain SIB(l) including the wake up signal configuration.

[0281] In a related embodiment that may be combined with other embodiments or used independently, the wake-up signal and a low power synchronization signal may be transmitted following a similar common schedule, wherein the wake-up signals fill in gaps in between the low power synchronization signals. This may be advantageous because it allows a receiver to keep synchronized knowing that the synchronization signals occur with a period T_SS, and in between, the receiver may only need to monitor the LP-WUS transmitted with period T_WUP, and if no signal is determined go back to sleep. The period T_WUP and T_SS may be related, e.g., be a fixed or configurable multiple. The communication resources (or repetitions) to transmit a first signal (e.g., synchronization signal) may be related to the communication resources (or repetitions) to transmit a second signal (e.g., wake-up signal). The communication resources allocated to a first signal may be implicitly indicated / determined given the communication resources allocated to a second signal, wherein, e.g., an access device may perform the allocation / configuration of the resources to, e.g., a wireless device.

[0282] The above embodiment as well as other embodiments may be illustrated by means of Fig. 9 wherein the regular distribution of a first type of signals 900, e.g., low-power synchronization signals is depicted, wherein the first signal is distributed in this specific / illustrative example with period T_SS and each signal is transmitted twice (and thus, communication resources for the transmission of two signals may be allocated). A second type of signal 901, e.g., wake up signal is transmitted with period T_WUS. Communication resources are allocated to a wireless device for monitoring this second type of signal. In this example, this second type of signal are transmitted four times, and a wireless device may be configured to monitor the second type of signal up to four times and the wireless device may determine locally how many times it needs to monitor the signal to obtain / receive it (e.g., as per other embodiments). It is also possible to see that the second type of signal may be transmitted during / after the first type of signal as 902.In a related embodiment that may be combined with other embodiments or used independently, the signal may be a low power wake-up signal (LP-WUS) and the measurement of the signal is the measurement of one of a low power wake-up signal. For instance, K LP-WUS monitoring occasions (MOs) may be allocated for a beam, and may be divided into X (X>=1) groups of R LP-WUS MOs. A wireless device may monitor all or some of the MO(s) within the K LP-WUS MOs. For each group of R LP-WUS MOs, the same LP-WUS information may be transmitted as in other embodiments. Different LP-WUS information may be transmitted in different groups of R LP-WUS MOs. Signals transmitted in a group of R LP-WUS MOs may be monitored according to some embodiments.

[0283] In a related embodiment that may be combined with other embodiments or used independently, the measurement of the signal is the measurement of one of:

[0284] - a low power synchronization signal, e.g., a LP-SS transmitted with a low frequency, e.g., every T = 320 ms or more and that is transmitted in short bursts, e.g., every T seconds N LP-SS are transmitted and a wireless device is configured to monitor up to M out of them.

[0285] - an emergency message, e.g., transmitted from an NTN access device N times to ensure its reliable transmission and a wireless device is configured up to monitor up to M transmission occasions;

[0286] - similar to the emergency message, it may be a paging early indication, and / or a paging message, and / or a downlink message;

[0287] - an uplink message, e.g., a Wake-up signal transmitted from a wireless device to an (NTN) access device. In this case, a first access device (e.g., primary cell) may have configured the wireless device with a number of communication resources to transmit the WUS up to N times and a second access device (e.g., a secondary cell) may be configured (e.g., by the first access device) to monitor up to M messages / WUS.

[0288] In a related embodiment that may be combined with other embodiments or used independently, the signal may be a wireless sensing signal and the measurement of the signal may be the measurement of the reflection of the wireless sensing signal. The wireless sensing signal may be, e.g., a chirp signal, and the chirp signal of duration T between frequencies fO and fl may be repeated N times, the wireless sensing signal may be an OFDM-based wireless sensing reference signal that may also be repeated multiple times. The wireless sensing signal may be distributed by the second wireless device. The first wireless device may receive the reflection of the wireless sensing signal and may be configured to monitor up to M chirps (in general, repetitions of a basic wireless sensing signal). The2025P00096EP03

[0289] wireless device may determine whether an object is being sensed depending, e.g., on the signal strength detected in a first monitoring occasion, e.g., in a first time slot used for wireless sensing. This may be a second set of communication resources. Only if an object is being sensed in such a second set of communication resources and / or the sensing measurement is not of sufficient quality, the wireless device may attempt to perform further wireless sensing in subsequent communication resources (which in this case may be called sensing resources), e.g., a third set of communication resources. Similarly, the wireless device may determine to stop monitoring chirps (sensing signals), e.g., to save energy. It may take the decision to stop monitoring chirps (sensing signals) when the wireless sensing measurement fulfils certain criteria, e.g., if the measurements in the second set of communication resources are sufficient, the wireless device may stop further measurements and may skip further monitoring. When a wireless sensing signal is repeated up to M times, e.g., a chirp, the wireless device receiving the reflection of the wireless sensing signal may aggregate some of the repetitions, e.g., in groups of S wireless sensing signals.

[0290] The wireless device receiving the wireless sensing signal may extract one or more parameters associated with the reflection characteristics of the sensed environment and / or detected objects. Such parameters may include, for example, delay / range, Doppler or velocity, angle (e.g., horizontal and / or vertical components of 3D angle), received power, and optionally one or more confidence metrics associated with each measurement.

[0291] In some examples, the wireless device may further derive parameters at different measurement levels, such as raw-data-level quantities (e.g., amplitude and phase samples), partial raw-data profiles in delay, Doppler, and / or angle domains, or higher-level per-path or per-point features extracted from the sensing signal.

[0292] In some configurations, multiple detected points sharing the same delay and Doppler but different 3D angles may correspond to a single detected path, for example when angular ambiguity occurs at the TRP / gNB. Similarly, multiple detected points may correspond to distinct scattering features of the same physical object, and the device may optionally associate these measurements across multiple sensing occasions.

[0293] Depending on the configuration, the wireless device may also compute higher-level object / target measurements, such as estimating one or more position-velocity pairs in a global coordinate system. These measurements may be reported individually or may include associations across consecutive sensing timestamps when supported.

[0294] This embodiment may be illustrated by means of Fig. 11, wherein the (wireless sensing) signal transmitted by a second wireless device is illustrated. This signal may comprise a first2025P00096EP03

[0295] signal 1100 and / or a second signal 1101 and / or a third signal 1102 and / or a sixth signal 1103. The first signal may comprise a chirp (in general, a wireless sensing signal since it does not need to be limited to a chirp type of signal) 1100-1 and / or a block of information (communication signal 1100-2). The chirp 1100-1 may span from frequencies fO to fl and last T1 seconds. The block of information may contain, e.g., an identifier. The second signal 1101 may include Ml repetitions of a wireless sensing signal, e.g., a chirp. In this case, 3 repetitions are depicted. The third signal 1102 may include M2 repetitions of a wireless sensing signal, e.g., a chirp. In this case, 3 repetitions are depicted. There may be a fourth and a fifth, etc signal similar to the second and third signals. Finally, a sixth signal may be transmitted, e.g., similar to signal 1100. The block of information 1103-2 may signal that the overall signal has finished. A wireless device may be configured to monitor communication resources (or sensing resources) used to transmit, e.g., 1100, 1101, 1102, and 1103. As per other embodiments, 1101 and / or 1102 may not need to be monitored if, e.g., 1100 is not received. 1102 may not need to be monitored if the quality obtained from the signal measurements of 1100 and / or 1101 is sufficient. As per other embodiments, the signal (e.g., chirp) repetitions in, e.g., signal 1101, may be combined to improve the signal quality.

[0296] In an embodiment of the disclosure that may be combined with other embodiments or used independently, the wireless device may determine a monitoring mode forthe wireless sensing signal, wherein the wireless device needs to monitor and / or measure the (repetitions) of the (reflected) wireless sensing signal until one or more conditions are met, e.g., until the quality / confidence level in the detection of a target is higher than a first threshold, e.g., until certain measurements remain stable up to a second threshold, etc. Additional parameters may further determine whether the wireless sensing signal is measured with sufficient quality. For instance, the wireless device may evaluate one or more physical-layer metrics associated with the reflected signal, such as the signal-to-noise ratio (SNR), the signal-to-interference-plus-noise ratio (SINR), the received signal strength indicator (RSSI), the error vector magnitude (EVM), or the error variance of estimated sensing parameters. Stability of phase measurements over multiple repetitions, consistency of Doppler shift estimates, or convergence of range estimates to within an allowable error margin may also be used as criteria. Furthermore, the wireless device may assess confidence metrics derived from detection algorithms, e.g., correlation peak sharpness, matched-filter output power, likelihood ratios, or the variance of peak positions across consecutive sensing occasions. If any of these parameters indicate that the sensing quality remains below a configured threshold— such as large fluctuations in measured range, excessive phase jitter, wide Doppler spread, or inconsistent angle-of-arrival estimates— the wireless device may continue monitoring additional repetitions. Conversely, if themeasured parameters satisfy predefined stability or accuracy criteria, the wireless device may determine that additional monitoring is unnecessary and may suspend further sensing operations to save energy.

[0297] Reliability and resilience are important goals when distributing some messages or signals, e.g., emergency messages, e.g., from an NTN device, and thus, in an embodiment that may be combined with other embodiments or used independently, a first wireless device may be configured with a plurality of occasions / occurrences (communication resources) when the different messages / signals (e.g., first message and / or second message) may be distributed. For instance, a first message (e.g., wake up signal and / or paging message and / or emergency message) may be distributed N times in a given set of communication resources, e.g., a period of time T. For instance, N repetitions distributed in time, or N repetitions distributed in different frequencies, or N repetitions distributed in different spatial streams (e.g. pre-coding matrix), or N repetitions using different codes, or N repetitions in time / using different frequencies / using different codes. This can be advantageous since there are devices with different clock accuracies, devices with different radio capabilities, devices with different radio communication links (e.g., line of sight vs non-light of sight) that may not be able to receive a message properly if it is sent a single time. However, forcing the devices to monitor all N repetitions may be energy consuming. Wireless devices may be given a configuration to monitor certain (e.g., a subset M of) resources, e.g., a time window TW within T, or a subset of frequencies, etc. to monitor those messages. The configured resources to monitor, e.g., the time window TW, may also be different for different (types of) wireless devices, e.g., depending on how many times a message may need to be received to ensure a certain level of reliability and resilience for a specific device, depending on the type of device, location, energy budget, etc. For instance, the first message (e.g., paging message or wake up signal) may be a configuration provided by the network when the wireless device connects to it, e.g., by means of an RRC message. For instance, the first message may carry the configuration for the reception of a second message / emergency message. A wireless device may then be required to monitor the configured communication resources knowing that they carrythe relevant message. The wireless device mayuse multiple measurements of multiple messages to aggregate the signal / message, and improve the reliability when retrieving the corresponding message, e.g., first message and / or emergency message.

[0298] In an embodiment that may be combined with other embodiments (e.g., the previous one) or used independently, the resources used to transmit the messages may belimited by, e.g., non-transmission periods, e.g., a non-transmission period before and after a transmission or in the surrounding frequencies. If a wireless device determines that the configured resources used to receive the first and / or emergency messages have a lower signal strength, in general, better fulfil a given criterion, than the resources, e.g. reference signals, surrounding it, the wireless device may be configured (e.g., based on a policy / configuration) to monitor other configured resources. This additional monitoring may be done even if the wireless device is not capable of decoding the signal properly. In general, the criterion may be configurable and may determine the communication features to consider (e.g., signal strength and / or quality of the decoded signal / message and / or whether parts of the message can be decoded, etc), signal strength difference between the configured resources used to receive a signal and surrounding resources triggering further monitoring, whether part or whole of the signal needs to be decodable to trigger further monitoring, etc. If further monitoring is performed or required in a second set of resources, the wireless device may combine the messages / signals obtained from the first set of resources and second set of resources to obtain a signal of better quality (e.g., better Signal to Noise ratio). This embodiment is advantageous because it allows a wireless device to monitor a first set of resources only, and only if a potential signal is suspected, one or more second set of resources needs to be monitored. This approach provides a good trade-off between energy requirements of the wireless device and reliability when receiving communication signals.

[0299] The above embodiments and other embodiments may be illustrated by means of Fig. 8 that schematically represents a set of resources (e.g., time / frequency) resources and the signaling used to transmit a signal (e.g., wake up signal, paging message, emergency message) in a reliable manner while keeping into account energy consumption of wireless devices. An access device may be configured to transmit a signal of interest, e.g., first message, e.g., paging message or wake up signal, in a set of resources (e.g., at times t1, t2, and t3 using frequencies f1 and f2). Furthermore, the resources around some of the selected resources may be kept “empty”, i.e., non-signal, i.e., zero signal (ZS). This may allow a wireless device to better determine whether there is a signal being transmitted in the selected resources. A wireless device may be provided with a policy / configuration determining the set of resources to monitor, e.g., frequencies f1 at times t1, t2, and t3, whereby some of the monitoring may only be performed if an event occurs, e.g., when there is an indication that, e.g., some of the resources (e.g., at a first frequency f1 and a first time t1) may carry a signal, and this indication may be obtained by comparing one or more communication features, such as, e.g., the signal strength,2025P00096EP03

[0300] of the signal in such a first / time resources with the one or more communication features of surrounding frequencies / times. For instance, a wireless device may monitor usually only resources t1 / f1 unless it is determined that the signal strength in t1 / f1 is lower than in the surrounding resources,e.g., in reference positions. In this case, the wireless device is required to further monitor f1 at t2 and t3 and use that information in all communication resources to receive the messages, e.g., to improve the quality of the received signal. The wireless device may use the information in all communication resources to receive the message, e.g., by combining (adding the received signals) to reduce the noise, e.g., by maximum ratio combining, e.g., by only decoding the message in the resource with the highest signal strength, e.g., by decoding the messages in each of the measured signals followed by majority voting, i.e., selecting the most frequent decoding result, etc. The procedure in Fig. 8 may be used, e.g., to make the reception of wake-up signals / paging messages / early paging / emergency messages more efficient / reliable, messages more efficient / reliable, messages more efficient / reliable, messages more efficient / reliable.

[0301] Section: coverage enhancementsand uplink repetition

[0302] Some aspects of this embodiment of the invention are illustrated in the context of enhanced coverage in wireless networks, e.g., with the purpose of ensuring that a wireless device can communicate with and / or through an access device.

[0303] Some aspects of the invention rely on the usage of signal repetition. Signal repetition is a critical technique in wireless communication systems, particularly for enhancing coverage and improving signal quality. When a signal is transmitted multiple times, the probability that it will be successfully received increases. This document explores how signal repetition contributes to better coverage by increasing the signal-to-noise ratio (SNR).

[0304] Signal repetition involves the transmission of the same signal multiple times over a communication channel. Each of these repeated signals can be received independently or combined at the receiver to improve the quality of the signal. When a signal is transmitted multiple times, each instance of the signal is subject to different propagation characteristics such as path loss, fading, and interference. At the receiver, these multiple instances can be processed and combined to reconstruct a more accurate version of the original signal. Methods to achieve this may include: (1) Diversity Combining: Techniques such as maximal-ratio combining (MRC) or equal-gain combining (EGC) are2025P00096EP03

[0305] used to combine multiple received signals. This enhances the overall received signal quality by taking advantage of the diversity in the signal paths. (2) Repetition Coding: Redundant copies of (parts of) the signal are transmitted, and error correction algorithms are employed at the receiver to detect and correct potential errors, leading to improved reliability. (3) Time Diversity: The same signal is sent at different time intervals, reducing the likelihood that all instances will be affected by the same fading or interference condition.

[0306] The effectiveness of signal repetition in enhancing coverage is largely attributed to its impact on the signal-to-noise ratio (SNR). SNR is a measure of signal strength relative to background noise, and higher SNR values typically indicate better signal quality and reliability. When a signal is received multiple times, the noise components in each instance are typically independent and uncorrelated. By combining these multiple signal instances, the overall noise effect can be averaged out, effectively increasing the SNR. The mathematical basis for this improvement is rooted in the principles of additive noise reduction, where the combined signal has a higher power compared to the combined noise. Consider a simplified model where a signal X is transmitted N times and received as Y_l, Y_2,..., Y_N. If the noise in each received instance is N_l, N_2,..., N_N, the combined received signal Y can be expressed as (Y_l + Y_2 +...+ Y_N + N_1 + N_2 + N_N) / N. Given that noise N_i is typically zero-mean Gaussian noise, the variance of the noise component in the combined signal is reduced by a factor of N, resulting in an improved SNR.

[0307] In an embodiment that may be combined with other embodiments or used independently, we consider that a wireless device such as a User Equipment (UE) or a STA may need to perform a wireless procedure, e.g., initial access, e.g., establish a connection with and / or perform a data exchange with / through an access device. The wireless device may then transmit a signal denoted as second signal to a first access device. The wireless device may have and / or have received a configuration denoted a first configuration from the first access device and / or a second access device and / or a third access device. This first configuration may be used to determine how the second signal is transmitted, e.g., how it is "repeated". After transmission of the second signal to the first access device, the wireless device may establish a connection with the first access device and / or a second access device. Additionally or alternatively, after transmission of the second signal to the first access device, the wireless device may perform a data exchange with or through the first access device and / or a second access device.In an example, a wireless device may receive a configuration via a SIB from a first access device and the wireless device may transmit the second signal, e.g., a preamble, multiple times through two beams to establish the connection with the first access device.

[0308] In an example, a wireless device may receive a configuration (e.g., the first configuration) via a message, e.g., an RRC message, from an access device, e.g., the first access device or even third access device, the wireless device may transmit the second signal, e.g., a preamble, multiple times through two beams to establish the connection with the first access device.

[0309] In an example, a wireless device may receive a configuration via a SIB from the first access device and the wireless device may transmit the second signal, e.g., a preamble, multiple times through two or more beams. The first access device may then use the received second signals to obtain measurements, and inform a second access device. The second access device and the wireless device may then connect and / or perform a data exchange.

[0310] In an example, the third access device, e.g., a terrestrial base station, may provide a first configuration, e.g., via an RRC message, to the wireless device. The wireless device may be, e.g., a UE whose user is taking a cruise. The UE may then, in the middle of the ocean, require a call via a second access device, e.g., a GEO satellite. The UE may send one or more second messages to the first access device, e.g., a base station on the cruise ora LEO satellite, to trigger the setup of the connection with the second access device.

[0311] In some examples, some of the access devices may be mobile access devices, e.g., mounted on a vehicle or a UAV or a satellite. In some cases, the wireless device may also be mobile.

[0312] In some examples, the first, second, and third access devices may be distributed units, and / or transmission and / or reception points (TRPs), e.g., in a cell-free cellular system or a multiantenna system. The wireless device may wish to perform a wireless procedure, e.g., initial access, with one or more of those TRPs.

[0313] In an embodiment that may be combined with other embodiments or used independently, the wireless device may be capable of receiving a first message with the first configuration to access / communicate / contact the first access device and / or a second access device, and transmitting to the first access device up to N second messages with N equal or greater than 1,through M beams with M equal or greater than 1, and wherein the selection of N and M may be according to the first configuration. The wireless device may select specific beams based on criteria such as signal strength, interference levels, and the quality of the communication channel. This selection process ensures that the transmission is optimized for better performance and reliability. The first configuration may also be stored on the wireless device, e.g., as part of a specification. In some situations, a first part of the first configuration may be retrieved from the wireless device memory, and a second part of the first configuration may be received via a (first) message.

[0314] In an embodiment that may be combined with other embodiments or used independently, the wireless device may perform a data exchange with or through the first access device and / or a second access device. This means that the mere fact of sending the second messages by the wireless device and the first access device receiving those second messages may be a sufficient condition to allow the data exchange. For instance, the second messages may be the initial part of a random access procedure. For instance, the second messages may contain the data that needs to be exchanged, e.g. small data transmission, early data transmission.

[0315] In an embodiment that may be combined with other embodiments or used independently, the wireless device may connect to the first access device and / or second access device upon transmitting at least one of the N second messages. For instance, if the second messages are part of a random access procedure, in general, of a protocol to establish a connection, the successful exchange of the second messages allows establishing the connection. This can allow, e.g., the wireless device to contact the first access device, when required, or the other way around.

[0316] In an embodiment that may be combined with other embodiments or used independently, the path loss between the wireless device and the first access device may be lower than the path loss between the wireless device and the second access device. This may happen, e.g., when the first access device is closer to the wireless device than the second access device. For instance, the first access device may be a LEO satellite, and the second access device may be a GEO satellite. The first access device may be a more suitable candidate to receive the second messages, i.e., the messages that allow triggering the establishment of a connection or a data exchange. The first access device may inform the second access device about the reception of the second messages.

[0317] In an embodiment that may be combined with other embodiments or used independently, it may be beneficial to use a first access device at a first altitude (e.g., UAV or LEO2025P00096EP03

[0318] satellite) to establish the communication with a second access device at a second altitude, e.g., a GEO satellite. In some cases, the first access device may be an access device having a first path loss with the wireless device and the second access device may be another access device having a second path loss with the wireless device. For instance, a wireless device may not be able to wake up or trigger the communication with the second access device directly, but the wireless device may be able to do that through the first access device. In particular, the first access device may receive second messages, e.g., wake up signals (e.g., a preamble) to wake up and / or trigger the communication with the second access device. The first access device upon receiving such second messages, e.g., may contact (and optionally provide information / configurations to) the second access device and / or the wireless device to setup / enable the communication between them. This may comprise the second access device transmitting certain signals to the wireless device (e.g., reference signals, e.g., synchronization signals or a SIB (e.g., SI Bl) and / or the wireless device transmitting certain signals (e.g., preamble) to the second access device.

[0319] In a related embodiment that may be combined with other embodiments or used independently, the second access device may start said connection and / or data exchange with the wireless device. The first access device may provide the second access device with information to facilitate the connection and / or data exchange. For instance, information detailing the estimated location of the wireless device. For instance, information related to the wake up period of the device. In some cases, this information may be extracted from the second messages received from the wireless device.

[0320] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may start the connection and / or data exchange with / through the second access device. In some cases, the second access device may start the connection and / or data exchange.

[0321] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may know that the first access device serves as a bridge / relay and / or allows facilitating the connection with the second access device, e.g., the first access device may inform about this capability in a SIB, e.g., SIB1 or an NTN specific SIB. The wireless device may then use one or more second messages, e.g., a specific uplink wake up signal, to signal this need allowing for the setup of the connection with the second access device and / or data exchange with or through the second access device without the need to connect to the first access device first. In some cases, it may require setting up a connection with the first access device, and then performing, e.g., a handover to the second access device.In some cases, the first message may be one or more of:

[0322] an RRC message,

[0323] a SIB, e.g., SIB1,

[0324] received from the first access device, the second access device, and / or the third access device.

[0325] In an embodiment that may be combined with other embodiments or used independently, the wireless device may receive one or more reference signals, e.g., synchronization signals, the wireless device may measure one or more parameters of the reference signals, e.g., synchronization signals, and the wireless device may determine N (e.g., number of second messages that are transmitted) based on the one or more measured parameters and / or the first configuration, in other words, it may determine the number of times that the second message needs to be repeated / transmitted. The reference signals, e.g., synchronization signals may be transmitted, e.g., by the first access device. For example, depending on the signal strength of the reference signals, e.g., synchronization signals, the wireless device may determine whether it has to transmit the second message once, twice, and so on. In this invention, in this embodiment and other embodiments, the reference signals may refer to, e.g., synchronization signals, or channel state information reference signals, etc.

[0326] In an embodiment that may be combined with other embodiments or used independently, the wireless device may receive one or more reference signals, e.g., synchronization signals, the wireless device may measure one or more parameters of the reference signals, e.g., synchronization signals, and the wireless device may determine M based on the one or more measured parameters and the first configuration. In other words, the wireless device may determine the number of beams through which the second message needs to be transmitted. Furthermore, it may determine other parameters, e.g., the specific beams that need to be used. For instance, if a wireless device detects only five beams from a base station (e.g., first access device) and with a very low signal strength, the wireless device may determine that it is preferable to transmit the second messages through, e.g., three of them. For instance, the three that have the highest received signal strength. For instance, the beam that is received with the highest signal strength and the two beams that are adjacent to it.

[0327] As a matter of clarification, the number of beams used may refer to the number of beams of the access device that are addressed by the wireless device when transmitting the second messages.In an embodiment that may be combined with other embodiments or used independently, in order to determine the beams and / or number the beams used to transmit / perform the random access procedure through multiple beams, the wireless device may be configured with a configuration (e.g., first configuration) determining one or more of:

[0328] the minimum M_min number of beams that need to / can be used;

[0329] the maximum M_max number of beams that can be used;

[0330] a first threshold value for selecting only the minimum number of beams, e.g., if the threshold value refers to a signal strength of a SSB, if the measured signal strength is greater than the threshold value, only the minimum number of beams maybe used, but if the measured signal strength is less than the first threshold more than the minimum number of beams may be used;

[0331] a second threshold for determining which beams are eligible for the transmission through multiple beams. Only beams whose measurements, e.g., signal strength, are greater than the second threshold may be eligible, but if the number of eligible beams is less than M_min, some non-eligible beams may be used as well;

[0332] the conditions to use multiple beams, e.g., when the wireless device is moving multiple beams (e.g., more than the minimum) may be used, while if the wireless device is static, multiple beams (e.g., more than the minimum) may not be used. This may require, e.g., configuring a further threshold value, e.g., speed related, so that that UE can measure the current speed, and make choices based on it. For instance, when beam measurements are (highly) variable (e.g., the currently (within a first time window) strongest beam becomes rapidly less strong, and the currently second strongest beam becomes rapidly (within a second time window) the strongest one), multiple beams may be used;

[0333] a configuration determining how the number of beams used increases with the number of failed random-access procedures. For instance, the first random access procedure may start with the minimum number of beams that can be used, and the number of beams used may increase after one or more failed random-access attempts.

[0334] In some scenarios, for a wireless procedure such as initial random access (RACH), the determination of the total number of PRACH transmissions (number of transmitted first messages) per RACH attempt can be based on one or more of:

[0335] Option 1: a single RSRP threshold is introduced to determine whether multiple PRACH transmissions with different Tx beams can be applied

[0336] Option 2: each of the values of multiple RPSP thresholds corresponding to each of the values of the total number of multiple PRACH transmissionsOption 3: each of the values of multiple RSRP thresholds corresponding to each of the values of the number of repetitions of a PRACH transmission per Tx beam.

[0337] Option 4: UE determines total number of PRACH transmissions based on the number of beams it supports.

[0338] In some examples, when receiving one or more reference signals (e.g., SSBs), the wireless device performs one or more measurements (signal strength, signal quality, frequency shift, etc) and the wireless device may select one or more beams with one or more repetitions to transmit the second messages. The selection of the beams and / or the number of repetitions of second messages transmitted on each beam may depend on the results of the measurements.

[0339] For instance, the wireless device may select a single beam for which the received signal strength is higher than a first threshold. For instance, if one or more of the beams are used to transmit reference signals that are measured with an RSRP greater than the first threshold, the wireless device may select any of those beams (used to transmit the SSBs), or the one with the highest signal strength, or the one whose measured parameters best fulfils one or more conditions evaluated by the wireless device.

[0340] For instance, if one or more measured parameters do not fulfil one or more conditions (e.g., if received signal strength of all beams is lower than the first threshold), and the wireless device determines that the one or more measured parameters fulfil other secondary conditions (e.g., that the received signal strength (RSRP) of two or more beams is higher than a second threshold), the wireless device may determine that those two or more beams may be eligible for transmission of second messages via said beams.

[0341] For instance, which of those beams whose one or more measured parameters fulfil other secondary conditions are used for the actual transmission of second messages may depend on one or more third conditions, e.g., a third threshold. The third threshold may be used to determine that only beams whose received signal strength is higher than the received signal strength of the strongest received beam minus the third threshold are used for preforming multiple transmissions of second messages through different beams.

[0342] In an embodiment that may be combined with other embodiments or used independently, a wireless device may receive and use a configuration (e.g., the first configuration) determining whether beams of a single access device or beams of multiple (up to a maximum of) access devices may be used. For instance, a wireless device may determine that two access devices are potential access devices, in particular, synchronization signals distributed through two beams2025P00096EP03

[0343] transmitted from two access devices are potential candidates, e.g., a first and a second access device. The wireless device may perform an initial transmission (transmitting a second message / preamble) targeting two potential access devices. For instance, this may involve transmitting two or more second messages / preambles. The configuration may determine the maximum number of access devices a wireless device may address. This embodiment means that a wireless device may only perform the access device selection upon reception of the random access response from one or both potential access devices. For instance, the access device / beam selection may depend on the signal strength / quality of the random access response. For instance, the transmitted second messages / preambles may indicate that the wireless device is performing a random access procedure through multiple beams / access devices and / or the number of such beams / access devices For instance, the wireless device may include in the second message / preamble towards the first beam / access device an indication of the second beam / access device that it is trying to access simultaneously As a matter of clarification, one or more parameters in the first configuration may be common for several access devices.

[0344] As a matter of clarification, in an embodiment that may be combined with other embodiments or used independently, the wireless device may be configured with a first configuration that may comprise one or more parameters common to multiple access devices (e.g., the first access device and the second access device), e.g., a common RACH configuration for the one or two more access devices (e.g., communication resources for the transmission of one or more second messages, e.g., RACH Occasion (RO), RO Group, preambles). The wireless device may use the parameter(s) of the common configuration to perform a wireless procedure, e.g., initiate the access to the one or more access devices.

[0345] In an embodiment that may be combined with other embodiments or used independently, a wireless device may provide feedback / measurements about the beams that it has tried to use in more or less successful manner. For instance, if a wireless device is no mobile (e.g., like a fixed wireless access device, e.g. a residential gateway), or has low mobility, and some beams are less useful (e.g., because previous random access procedures failed), the wireless device may report this information to the network / access device. This may be indicated during the random-access procedure itself (e.g., embedded in a message such as preamble, or Msg 3) and / or in an RRC message. This may help the access device to determine the best beams to use for further communication. For instance, the access device may determine that the next time that the wireless device performs a wireless procedure, e.g., initial access, the wireless device needs to use M beams, and M specific beams.2025P00096EP03

[0346] In cellular networks, a wireless device, e.g., a User Equipment (UE) such as smartphones, tablets, and loT devices utilize antennas to communicate with access devices. The quantity of antennas or antenna panels is based on the device type and supported frequency bands. For sub-6 GHz frequencies, commonly employed in 4G LTE and 5G networks, wireless devices typically incorporate 2 to 4 antennas. These antennas facilitate Multiple-Input Multiple-Output (MIMO) technology, enabling the UE to transmit and receive multiple data streams simultaneously, thereby significantly enhancing data rates and improving link reliability. For instance, a wireless device equipped with 4 antennas can support 4x4 MIMO, which is ideal for high-throughput, spatial diversity, mitigating signal fading caused by multipath propagation and enhancing overall signal quality. Conversely, for millimeter-wave (mmWave) frequencies in 5G, UEs employ multiple antenna panels, each comprising several antenna elements functioning collaboratively as a phased array. These panels are pivotal for beamforming, a technique whereby the UE concentrates its signal in specific directions to counteract the high path loss and limited range inherent to mmWave bands. A typical 5G smartphone may feature 3 or 4 antenna panels, strategically positioned to ensure coverage regardless of the device's orientation. These panels facilitate beam management, allowing the UE to perform beam sweeping to ascertain the optimal direction for communication, and spatial multiplexing, which augments throughput by transmitting multiple data streams concurrently. Antennas support supplementary modes such as transmit diversity, where multiple antennas transmit the same signal to improve reliability, and receive diversity, where signals from multiple antennas are amalgamated to enhance reception. Furthermore, multiple antennas enable carrier aggregation, combining different frequency bands to increase bandwidth. As cellular technology progresses, the role of antennas in UEs remains crucial, with their number and configuration directly influencing the ability to leverage technologies like MIMO, beamforming, and diversity. This adaptability ensures that UEs can meet diverse use case demands, from everyday mobile browsing to high-speed data transfers in next-generation networks.

[0347] To this end, in an embodiment that may be combined with other embodiments or used independently, a wireless device may have multiple A antennas / antenna panels, and the wireless device may determine through how many B of the antennas / antenna panes an initial message (e.g., preamble) should be transmitted. For instance, a wireless device may determine the strongest beam / SSB of an access device. However, the wireless device is moving so that the "optimal" antenna may change. To address this issue, the wireless device may transmit the same second message towards the strongest beam / SSB of the access device through multiple antennas / antenna panels. The transmission may be simultaneous, or time multiplexed. The operation of this embodiment may also be controlled by means of a first configuration, e.g., determining whether in afirst attempt a single antenna / antenna panel should be used, and how the number of antennas / antenna panels should be increased.

[0348] It is to be noted that throughout this invention, a beam may refer to, e.g.,

[0349] (1) a beam used by the access device to transmit a first message, and / or (2) a beam used by the access device to receive a second message / preamble and / or (3) a beam transmitted by a wireless device to transmit the second message / preamble (e.g., using different antenna / antenna panels);

[0350] (4) a beam used by the access device to transmit a third message.

[0351] In an embodiment that may be combined with other embodiments or used independently, the wireless device may receive one or more reference signals, e.g., on demand or reference signals transmitted, e.g., every T seconds, e.g., 80 msec. The wireless device may use the first configuration to determine a first configuration of transmission parameters of the second messages at time tO (e.g., after receiving the first set of reference signals, e.g., in a first PRACH transmission / RACH attempt). If no answer is received, the wireless device may determine a second configuration of transmission parameters of the second messages, e.g., at time tl (e.g., after receiving a second set of reference signals), e.g., in a second PRACH transmission / RACH attempt. For instance, the first time at time tO, a single second message is transmitted. For example, the second time at time tl, 2 second messages are transmitted through a single beam. For example, the third time at time t2, 4 second messages are transmitted through two different beams. This embodiment represents an adaptive approach that allows adjusting the transmission parameters (of the second messages) depending on the communication link. This approach may provide a suitable balance between enhanced coverage and energy consumption.

[0352] In some scenarios, for multiple PRACH transmissions with different Tx beams, candidate values of the total number of PRACH transmissions are {2,4,8} in one RACH attempt.

[0353] In an example, two second messages via a single beam are transmitted.

[0354] In an example, four second messages via a single beam are transmitted. In an example, eight second messages via a single beam are transmitted.

[0355] In an example, two second messages via two beams are transmitted.

[0356] In an example, four second messages via two, three, or four beams are transmitted. In an example, eight second messages via two to eight beams are transmitted.In an example, the wireless device may obtain and / or the access device may signal which configurations are allowed. A configuration may refer to the number of repetitions in a single beam and / or multiple beams in total. For instance {(1), (2), (4), (8), (1,1), (2,2), (1,2,1), (4, 4), (2,4,2)} indicates 9 allowed configurations. (1) uses a single beam and a single repetition; (2,2) uses two repetitions and two beams, in general (al, a2,...ai,..., an) indicates that n beams are used, and ai indicates the number of repetitions in the i-th beam. The potential configurations may be indexed with the integers 1,2,.., L, where L is the number of allowed configurations, and a collection of allowed configurations may be indicated by a binary sequence of length L, a 0(1) in position i indicating that configuration with index is not allowed (is allowed), respectively.

[0357] In an example, the wireless device may obtain and / or the access device may signal a configuration determining how many repetitions (or transmissions) are used, and how many beams, e.g., {(1,1), (2,1), (4,1), (8,1), (2,2), (4,2), (4,3), (8, 4), (8, 3)} represent 9 configurations (a,b) wherein a indicates the number of transmissions, and b represents the number of beams. For example, for (4,2), either there are two beams both with two transmissions, or a beam with a single transmission and another beam with three transmissions. For each a, there are a potential configurations with a transmissions, viz (a, 1 ), (a, 2),.., (a, a). The number of potential configurations for 2,4 or 8 transmissions thus equals 2+4+8=14, and the potential configurations may be indexed by the integers 1,2,...,14, and a collection of allowed configurations may be indicated by a binary vector of length 14.

[0358] In an example, the wireless device may obtain and / or the access device may signal a configuration determining the order of the second messages in beams, e.g., {(1), (1,1), (1,1, 1,1), (1, 1,2, 2), (1,2, 1,2), (1,1, 2, 2, 2, 2, 3, 3) }. The number of entries in each configuration determines the total number of repetitions / transmissions. The entry in position i of a configuration indicates the index of the beam used for transmission i of a second message. For instance, (1) indicates a single transmission of a second message using beam 1. For instance, (1,1) indicates two transmissions of a second message using a single beam 1. For instance (1,1, 2, 2) indicates four transmissions of second messages using beams 1, and 2, the first two transmissions using beam 1 and the last two transmissions using beams 2.

[0359] In an example, the configurations may be known, and the active configurations are signaled by means of a bitmask, e.g., if the list {(1,1), (2,1), (4,1), (8,1), (2,2), (4,2), (4,3), (8, 4), (8, 3)} is known, it may be possible to transmit (1,1, 1,1, 1,0, 0,0,0) to indicate that the first 5 entries are active / allowed / can be used by a wireless device, and the last 4 are not allowed. The bitmask may be with respect to the list of allowed configurations, or with respect a pre-specified list of all potential configurations.In an example, the configurations may be known, and the active configurations are signalled by indicating the index of the first inactive configuration / index of the last active configuration, e.g., in previous example, it may be possible to transmit just 4 as the index of the last active configuration.

[0360] These examples allow signaling the configurations that are active / inactive.

[0361] It is to be noted that these configurations may also refer to the time / frequency resources used to transmit the one or more second messages via one or more beams.

[0362] In an embodiment that may be combined with other embodiments (e.g., the previous two) or used independently, the one or more parameters that may be measured from reference signals, e.g., synchronization signals may comprise one or more of:

[0363] signal strength of each reference signal,

[0364] signal quality of each reference signal,

[0365] measured frequency shift of each reference signal,

[0366] angle of arrival of the reference signal.

[0367] In some examples, the time / timing between second messages may be determined based on the first configuration. This timing may be, e.g., for repetitions through a same beam, and / or through repetitions through two or more beams.

[0368] In some examples, the wireless device may transmit the second messages through M different beams according to a beam transmission mode and the beam transmission mode is one of:

[0369] (1) simultaneously, i.e. two or more second messages are transmitted through two or more beams simultaneously;

[0370] (2) sequentially, i.e., second messages are transmitted through a single beam or through multiple beams one second message after another, for instance, N1 second messages are firstly transmitted through a first beam and then N2 second messages are transmitted through a second beam;

[0371] (3) alternating, i.e., second messages are transmitted through different beams in an alternating manner, for instance, N1 second messages are firstly transmitted through a first beam, then N2 second messages are transmitted through a second beam; then N1 second messages are transmitted through the first beam, then N2 second messages are transmitted through the second beam; etc.

[0372] (4) increasing, i.e., an increasing number of second messages are transmitted, for instance, one second message is firstly transmitted through a first beam, then one second message istransmitted through a second beam; then two second messages are transmitted through the first beam, then two second messages are transmitted through the second beam; etc.

[0373] The beam transmission mode may be configured, e.g., by means of the first configuration. The parameters used in the beam transmission mode may also be configurable.

[0374] In some examples, at least one of the N second messages encodes the value N. This may be advantageous so that the receiving access device can determine the number of repetitions of the second message.

[0375] In some examples, the second message transmitted in k position encodes the value k. For instance, if the second message is transmitted twice, the first transmitted second message may encode the number "1" and the second transmitted second message may encode the number "2". For instance, it may encode the temporal position when the multiple second messages are time multiplexed. For instance, the second messages may encode different sequence numbers (related to the position term before), where a second message with a lower sequence number is transmitted at the same or at an earlier time than a second message with a higher sequence number.

[0376] In some examples, a first (or current) second message encodes the beam identifier used to transmit a second (or subsequent) second message. In other words, if the wireless device decides to transmit the second messages through beams bl and b2, the second messages transmitted through beam bl may include the identifier of b2, and vice versa. In some cases an access device may have many beams, e.g., 64 beams and encoding a beam identifier requires therefore 6 bits. However, a wireless device may indicate related beams in a relative manner. For instance, if a wireless device selects beams 33, 34, and 35, and the main choice is beam 34 (e.g., because it is the beam for which the measured signal strength is the strongest one), beam 34 may be identified by means of 0, beam 33 may be identified by the relative position to the main beam, i.e., -1, and beam 35 may be identified by the relative position to the main beam, i.e., 1. This approach reduces the overhead. This approach also allows identifying which beams are preferred and / or their relative position to the preferred one.

[0377] In some examples, the same second message (e.g., preamble) may be transmitted in each of the selected beams. In some cases, different second messages (e.g., different preambles) may be sent in different beams. In some cases, the second messages transmitted in different beams may be variations of a same root message. For instance, a cyclic rotation of a root message. For instance, if the strongest beams are beam 33, 34, and 35, and a root sequence is 000001000000, then the root sequence may be transmitted as it is to beam 34, and it may be transmitted with a left cyclic rotationtowards beam 33 (previous beam), e.g., as 0000 10000000, and it may be transmitted with a right cyclic rotation towards beam 35 (next beam) e.g., as 00000010000.

[0378] In general, the invention may be used to enhance coverage during a wireless procedure, e.g., random access. The second messages may be preambles transmitted multiple times / through different beams. A challenge is that the access device may consider that the multiple transmissions in different beams of the second messages originate in multiple wireless devices, and not a single one. To deal with this, one or more embodiments may be applicable:

[0379] In an embodiment of the invention that may be combined with other embodiments or used independently, in some examples, a first (or current) second message encodes the parameters used to transmit a second (or subsequent) second message. It is to be noted that in some variant of this embodiment the second second message may be sent prior to the first second message, or even simultaneously. This embodiment is a generalization of other embodiments, e.g., the previous one, since other parameters may be also indicated, e.g., transmission power, and / or transmission time. For instance, the transmission power may be included, e.g., it may be included as a relative factor to the transmission power of the current beam. For instance, the transmission time of another second message may be encoded (and / or known), e.g., relative to the transmission time of the current second message. For instance, a first second message (first preamble) may also encode an identity of the second second message (e.g., a second preamble). Additionally, or alternatively, the first and second second messages may be related, e.g., be the same and / or a simple modification / transformation (e.g., a cyclic rotation) of the same second message (e.g., a root sequence). This may allow an access device to determine what to look for and / or when to search for the related second messages and / or determine whether it is capable of decoding them.

[0380] In some examples, the N second messages may encode one or more identifiers, and the one or more identifiers are associated to the N second messages. Identifiers may include a wireless device identifier or a second message set identifier that links multiple second messages together. This may be useful, e.g., to determine that a group of second messages are associated to each other, e.g., are transmitted by the same wireless device.

[0381] In some examples, the second messages may be related to each other by the content. For instance, a root second message may be selected to be transmitted through a first second beam, and second messages in distributed through a second second beam and / or a third second beam may correspond to a transformation of the root second message, e.g., a cyclic shift.In general, the type of the transformation (e.g., cyclic shift to the right or left and / or amount) of the root second message (e.g., root Zadoff-Chu sequence) may depend on the spatial location of the beams and / or the communication resources / transmission occasions selected and / or the beam indexes, e.g., if three beams are selected with three different indexes (b-1, b, b+1), the transformation may depend on the beam index differences, e.g., (-1, 0, 1), obtained from (b-1, b, b+1) by subtracting b.

[0382] In some scenarios, an access device may configure in a wireless device a first set of one or more second messages (e.g., preambles) to be used when the wireless device transmits one or more second messages through a single (M=l) beams. In some scenarios, the access device may configure in a wireless device a second set of one or more second messages (e.g., preambles) to be used when the wireless device transmits one or more second messages through multiple (M>1) beams. In some cases, the access device may allocate an mth set of one or more second messages to be used when the wireless device transmits one or more messages through m beams.

[0383] The set of second messages to be used depending on the number of beams used when transmitting the second messages. For instance:

[0384] If a single beam is used, a set of second messages with indexes 0, 1, 2, 3 may be used

[0385] If two beams are used, a set of second messages with indexes 4, 5 may be used, If four beams are used, a set of second messages with indexes 6, 7 may be used. In an example, an index may represent a specific ZC root sequence, o a specific preamble.

[0386] In an example, when the wireless device transmits the N second messages, the wireless device may select one or more of the second messages in the corresponding set (depending on the number of beams used), and may transmit that second message N times.

[0387] In an example, the wireless device may also select a second message with a given index, and transmit the selected second message with small shifts through the different beams, e.g., as in other examples of the invention. This allows linking second messages to each other.

[0388] In an example, the second messages in different sets (e.g., second messages with indexes 6, 7) may be selected in such a manner than shifted versions of the second messages 6 and 7 can be distinguished from each other, and / or other second messages in other sets.

[0389] In an example, the wireless device may select a second message from the corresponding set, and transmit the same second message in all selected beams.For instance, if the second second beam is (spatially) located before the first second beam, the cyclic shift may be to the left b bits. For instance, if the third second beam is (spatially) located after the first second beam, the cyclic shift may be to the right b bits.

[0390] For instance, if the wireless device may select transmission occasions 11000000

[0391] 00011000

[0392] 00000110

[0393] these transmission occasions may be defined / determined by means of a codeword out of 24 transmission occasions. The transmission occasions may be mapped to beam and time resources. For instance, a first, second, and third beams, and 8 time slots. For instance, the first codeword may be assigned to the first beam, the second codeword part may be assigned to the second beam, and so on. The second beam may be the strongest one (currently measured), thus, the root sequence may be transmitted in the communication resources of the second beam. Thus, the root sequence may be transmitted in the central time resources assigned to the second beam, e.g., time slot 4 and 5. For instance, the first beam may be spatially located on the left, so the root sequence may be cyclic shifted to the left y*X bits, where y=3 corresponds to the number of bit shifts between the the first part of the codeword (assigned to the first beam) and the second part of the codeword (assigned to the second beam). Similarly, the third beam may be spatially located on the right, so the root sequence may be cyclic shifted to the right y'*X bits, where y=2 corresponds to the number of bit shifts between the second part of the codeword (assigned to the first beam) and the third part of the codeword (assigned to the third beam). X may be the (unit of) number of bits that are cyclic shifted.

[0394] In some examples, the second messages may be related to each other by the communication resources and / or transmission occasions (e.g., random occasions (RO)) used to transmit the second messages. For instance, the wireless device may have a configuration determining sets of communication resources / transmission occasions (e.g., determined by means of a codeword / codebook as in other embodiments / examples) that may be used together to transmit the N second messages. Thus, all second messages transmitted in those N transmission occasions can be considered as related. This means that the wireless device may be configured to support separate ROs when performing a wireless procedure, e.g., random access, using multiple beams.

[0395] In some examples, the second messages may be related to each other by the communication resources and / or transmission occasions used to transmit the second messages. For instance, the wireless device may have a configuration determining sets of communicationresources / transmission occasions (e.g., determined by means of a codeword / codebook as in other embodiments / examples) that may be used together to transmit the N second messages. Thus, all second messages transmitted in those N transmission occasions will consider as related.

[0396] In some examples, the transmission occasions / communication resources for transmitting one or more second message (preambles) multiple times may be a different than transmission occasions / communication resources for transmitting a second message (preamble) a single time. This allows the access device to differentiate between a wireless devices transmitting multiple second messages and wireless devices transmitting a second message a single time.

[0397] In an embodiment that may be combined with other embodiments or used independently, the beams selected to transmit the second messages are selected based on contextual information, e.g., the moving direction of the wireless device and / or first access device. For instance, even if a beam seems to be weak (based on the received reference signals, e.g., synchronization signals), if the wireless device determines that (e.g., based on their moving direction) the beam is likely to become more suitable for further communication, the wireless device may select such a beam for the transmission of second messages as well. Similarly, the access device may reply using a different beam, and / or the wireless device may monitor a different beam that is expected to be preferred.

[0398] In an embodiment that may be combined with other embodiments or used independently, the wireless device may be configured with an AI / ML model and the AI / ML model may allow the wireless device to determine suitable parameters for the transmission of the second messages, e.g.: N, M, selected beams, transmit power, etc. The AI / ML model may also be configured as part of the first configuration or independently of it. The usage of such an AI / ML model for this task may also be enabled and / or disabled by an access device. The usage of such an AI / ML model for this task may also be made dependent to its performance, e.g., be disabled if no connection and / or data exchanged can be performed.

[0399] In a related embodiment that may be combined with other embodiments or used independently, a wireless device may have historical data (e.g., the last t ms or the last t seconds) about the beams that have the best performance, e.g., the beams / SSBs measured from an access device. The wireless device may have an AI / ML model / function that may allow predicting the beams / SSBs that are predicted to have the best performance at a subsequent point of time.

[0400] For instance, if an access device has a fixed beam / SSB configuration (i.e., beams / SSBs do not move and cover a fixed area) and wireless device moves (and / or the wireless access device moves), the wireless device may observe / measure how based on their relative movement some ofthe beam measurement values (e.g., signal strength) increase / decrease. The wireless device may then select one or more beams based on such predictions for the transmission of the second messages.

[0401] For instance, when sending one or more second messages (e.g., preambles) for the initial random access, the wireless device may select the beam that currently offers the best communication link (e.g., measured with the highest signal strength) and the beam that is expected to offer the best communication link at a subsequent time (e.g., when receiving a later message, e.g., a third message.

[0402] In an embodiment that may be combined with other embodiments or used independently, the wireless device may transmit one or more second messages (e.g., preambles) to an access device through a first beam. The one or more second messages may include an indication of and / or indicate a second beam that may be used by the access device to transmit a third message (e.g., random access response) to the wireless device (in general, to perform a data exchange between wireless device / access device). This embodiment may apply, e.g., when the wireless device has an AI / ML model that allows predicting which beams may be more suitable for the communication in the uplink (e.g., transmit the second message) and downlink (e.g., receive the third message). In this case, instead of having to transmit the second message through both the first and second beams, the uplink is done through the first beam and the downlink is done through the second beam. The wireless device may have a configuration (e.g., first configuration) determining whether this operation is feasible / allowed. This operation may be triggered based on one or more conditions, e.g., as in previous embodiment.

[0403] In an embodiment that may be combined with other embodiments or used independently, the second messages are transmitted through at least a wide beam and at least a narrow beam, in other words, the narrow beam may be narrower than the wider beam. This may be beneficial because the (first) access device may monitor, e.g., first, the wide beam, and then use a "hint" in the signal (e.g., a second message) received through the wide beam, to monitor the corresponding narrow beam or narrow beams. This is illustrated by means of Fig. 15 as elaborated below.

[0404] In an embodiment that may be combined with other embodiments or used independently, an access device, upon reception of one or more second messages may transmit to the wireless device multiple third messages, e.g., L third messages with L equal or greater than 1. The wireless device may therefore be adapted to receive up to L third messages. The third messages may be used to confirm / setup the connection. The third message may be, e.g., a random-access response.In a related embodiment that may be combined with other embodiments or used independently, the access device may transmit the third messages in different manners, e.g., one or more of:

[0405] one or more third messages after the reception of each second message, this may be advantageous because the wireless device receives feedback as early as possible from the first access device and it can allow for a more efficient communication;

[0406] up to L third messages after the reception of all N second messages, this is advantageous because it allows the first access device to obtain the second message in the most reliable manner;

[0407] the third messages may be transmitted through all the beams used for the reception of the second messages, this ensures path diversity in the transmission back to the wireless device;

[0408] the third messages may be transmitted through a selection of the beams used for the reception of the second messages, e.g., one or more of those beams in which the second message was decoded or was received fulfilling certain criteria, e.g., high enough received signal strength, e.g., the best beam, this allows reducing resource needs and performing beam selection.

[0409] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may be adapted to perform the opposite actions of the last embodiment, e.g.: receive at least one third message after the transmission of a second message; and / or receive up to L third messages after transmitting all N second messages, etc.

[0410] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may be adapted to perform the data exchange with or through the first access device and / or second access device as a result of receiving at least 0 third messages, with 0 equal or greater than 1. In other words, the wireless device may require receiving multiple third messages to communicate further. This may be advantageous to ensure a sufficient link quality. The value 0 may be encoded in one or more of the third messages, and / or be provided by means of the first configuration, etc.

[0411] In an embodiment that may be combined with other embodiments or used independently, the wireless device may stop transmitting any further second messages as a result of receiving at least one third message. This may be advantageous to reduce latency and energy consumption while ensuring higher reliability and coverage.

[0412] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may stop transmitting any further second messages through a second beam as a result of receiving at least one third message through a first beam. This may allow the wireless device to reduce energy consumption. When the wireless device receives the secondmessage through the first beam, the wireless device may understand that the second beam is not a preferred beam for further communication.

[0413] In a related embodiment that may be combined with other embodiments or used independently, when a wireless device uses two or more beams to send the second messages, the wireless device may determine the preferred beam for further communication based on the beam used by the access device to provide the third message. This embodiment provides therefore an implicit indication of the preferred / chosen beam by the access device.

[0414] In a related embodiment that may be combined with other embodiments or used independently, the second message may be one or more of:

[0415] a preamble to perform a random-access procedure,

[0416] an uplink wake-up signal,

[0417] a message to complete the setup of a radio resource control protocol.

[0418] In a related embodiment that may be combined with other embodiments or used independently, the third message may be one of:

[0419] random access response message.

[0420] an RRC Registration Request,

[0421] an RRC Connection Complete,

[0422] an RRC Connection Reconfiguration Complete.

[0423] In a related embodiment that may be combined with other embodiments or used independently, the wireless device may determine a preferred beam for further communication based on one or more of:

[0424] an indication (implicit or explicit) on at least one third message and / or measurements (e.g., signal quality / strength) of the third messages and / or measurements (e.g., signal quality / strength) of the reference signals, e.g., synchronization signals.

[0425] This approach may provide a more reliable selection mechanism when selecting a communication beam since it is based on not only on the choice of the wireless device but also on, e.g., the indication of the access device and / or measurements of both the wireless device and the first access device.

[0426] In a related embodiment that may be combined with other embodiments or used independently, the first configuration may comprise one or more of:

[0427] transmission power of the reference signals, e.g., synchronization signals, load indication of the first access device,

[0428] load indication of the second access device,indication of the maximum N, M, L, and 0 values allowed and / or used by the first access device and / or second access device,

[0429] beam transmission mode,

[0430] timing between transmission of second messages when sent through the same and / or different beams (e.g., referring to T_l, T_2, T_3, T_4, T_5 as per Fig. 16),

[0431] one or more values (allowing) determining the N value based on the one or more measured parameters and / or a fixed configuration,

[0432] one or more values (allowing) determining the M value based on the one or more measured parameters and / or a fixed configuration,

[0433] adapting rules that allow adapting the different parameters, e.g., N, M,... depending on the context, e.g., when no answer (no third message) was received after a first transmission of N second messages,

[0434] transmission parameters as a function of N and / or M, wherein the transmission parameters may comprise one or more of transmission power, timing, encoding, and modulation of one or more of the N second messages,

[0435] an AI / ML model used to determine suitable parameters, e.g., N, M, selected beams, or timing values;

[0436] monitoring / transmission mode;

[0437] communication parameters of, e.g., second messages, such as time location, frequency location, pre-coding matrix of the spatial stream, etc.

[0438] In a related embodiment for enhanced coverage when providing access to a network that may be combined with other embodiments or used independently,

[0439] the first access device may receive one or more times a second message from a first wireless device attempting to connect to the network,

[0440] the first access device may transmit L third messages with L greater or equal than 1 upon reception of one or more second messages, and

[0441] the first access device may perform or enable a data exchange with the first wireless device.

[0442] In a related embodiment for enhanced coverage when providing access to a network that may be combined with other embodiments or used independently,

[0443] the first access device may receive one or more times a second message from a first wireless device attempting to connect to the network,2025P00096EP03

[0444] the first access device may transmit an indication to the second access device, wherein the indication indicates the reception of the one or more second messages from the first wireless device.

[0445] In a related embodiment for enhanced coverage when providing access to a network that may be combined with other embodiments or used independently,

[0446] the second access device may receive an indication from a first access device, wherein the indication may indicate the reception of the one or more second messages from the wireless device.

[0447] the second access device may transmit L third messages with L greater or equal than 1 upon reception of the indication, and

[0448] the second access device may perform or enable a data exchange with the wireless device.

[0449] In a related embodiment for enhanced coverage when providing access to a network that may be combined with other embodiments or used independently, the first access device may transmit one or more of:

[0450] reference signals,

[0451] synchronization signals,

[0452] a SIB message containing a first configuration,

[0453] an RRC message containing a first configuration,

[0454] an RRC Registration Request,

[0455] an RRC Connection Complete,

[0456] an RRC Connection Reconfiguration Complete,

[0457] In a related embodiment for enhanced coverage when providing access to a network that may be combined with other embodiments or used independently, the first access device may determine a preferred beam for communication with the wireless device based on the one or more received second messages.

[0458] An access device such as a base station may be able to support receive multiple second messages (repetitions of the second messages) over multiple beams (e.g., as per embodiments of the invention) and the access device may need to give access to both wireless devices supporting embodiments in this invention as well as legacy devices (that do not support repetitions over multiple beams). For instance, a Release 195G UE may be a legacy device while a Release 205G-Advanced may be a non-legacy device.2025P00096EP03

[0459] A question is how an access device should behave to support legacy devices while still enabling enhanced performance in devices supporting repetitions over multiple beams. To address this problem:

[0460] In an embodiment of the invention that may be combined with other embodiments or used independently, an access device may indicate in a configuration in the first message (e.g., SI Bl) the support of repetitions through multiple beams, transmission of second messages through multiple beams, and one or more corresponding configurations. Legacy devices may ignore this one or more configurations, and rely on a legacy configuration, while non-legacy devices may use it.

[0461] In an embodiment of the invention that may be combined with other embodiments or used independently, a non-legacy wireless device may determine whether an access device may or may not support of repetitions through multiple beams upon reception of the configuration (e.g., in SIB1).

[0462] In an embodiment of the invention that may be combined with other embodiments or used independently, a non-legacy wireless device may determine whether to transmit one or more second messages via one or more beams upon receiving the configuration (in the first message) and receiving reference signals (e.g., an SSB burst / synchronization signals). The access device may then need to determine whether the wireless device is using repetitions through multiple beams or not, i.e., transmit second messages through a single beam or through multiple beams.

[0463] In an example, an access device may treat the second messages received through a first beam independently of the second messages received through a second beam. This may facilitate backwards compatibility because the access device does not distinguish whether a single wireless device is trying to gain access through two different beams or two wireless devices are trying to gain access each through a different beam. However, this approach does not allow the access device to assess which of the beams may be best in the case the wireless device is trying to gain access through two or more beams, in other words, the selection is with the wireless device only. If a wireless device transmitted two or more second messages through two or more beams, the wireless device may monitor resources for the reception of two or more third messages transmitted via the corresponding beams. The wireless device, if receives two or more third messages may select a single one, e.g., the preferred one based on one or more parameters of the reference signal and / or the received third messages. In a further subsequent message, the wireless device may inform the access device of the fact that some of the second messages were related and transmitted via different beams. This allows the access device to be aware that a single wireless device was seeking access.2025P00096EP03

[0464] In an example, upon reception of a first second message, the access device may check whether the first second message is indicative of the transmission of one or more second messages via multiple beams. For instance, second messages using specific identifiers (e.g., specific preambles) or using specific communication resources (time, frequency, beam) may be indicative of using repetitions (transmitting one or more second messages) through multiple beams. When the access device determines that the wireless device is (may be) transmitting through multiple beams, the access device may look for other related repetitions (or other related second messages). This approach allows the access device to assess which of the beams may be more favourable.

[0465] In an example, upon reception of a first second message, the access device may try to determine whether a second second message was transmitted / can be received via another beam by the same wireless device. The access device may be able to link the first second message and the second second messages, e.g., by knowing that the first second message and the second second message:

[0466] carry and / or indicate a common and / or related identifier (e.g., a common related preamble); and / or

[0467] are transmitted using common and / or related communication resources (e.g., frequency, time, beam resources).

[0468] For instance, a first second message may carry and / or indicate a first identifier and may be transmitted in a first set of resources (frequency, time, beam). The first identifier and / or first set of resources may be indicative of one or more second set of resources that may be used to transmit (by the wireless device) / receive (by the access device) one or more second messages. For instance, if an access device receives first second message with identifier ID (e.g., related to a preamble with index ID), in time T, and frequency F, in beam B_i, the access device may expect a second second message featured by one or more of:

[0469] with identifier ID' that may depend on ID, T, F, and B_i by means of a function Fl, e.g., ID' = ID, and / or

[0470] at time T' that may depend on ID, T, F, and B_i by means of a function F2, e.g., T' = T, or T' = T+k, and / or

[0471] at frequency F' that may depend on ID, T, F, and B_i by means of a function F3, e.g., F' = F, and / or

[0472] via beam B' that may depend on ID, T, F, and B_i by means of a function F4, e.g., B' = B_{(i+1) mod K} or B' = B_{(i-1) mod K} where K is the number of beams used by the access device.This approach allows reducing the search time at the access device, and it also allows the access device to determine which of the beams may be better or worse.

[0473] In an embodiment of the invention that may be combined with other embodiments or used independently, an access device may determine that one or more of the second messages that were expected to be received could not be received (e.g., due to bad conditions through a given beam). The access device may determine whether / how to adapt the transmission parameters for the one or more third messages (e.g., random access response messages).

[0474] For instance, the access device may indicate via SIB1 that a wireless device must use a number of beams when transmitted second messages.

[0475] For instance, the number of required beams may depend on one or more parameters, e.g., frequency range (frequency < 3GHz, between 3 and 6 GHz, or > 6 GHz), the beam index (since different beams are usually transmitted towards different areas), the RSRP, etc. This may also be indicated by means of the configuration.

[0476] For instance, the access device may only transmit third messages through beams through which second messages were received properly. For instance, if the wireless device transmits second messages through a first, second, and third beam, and only second messages through the first and third beams, are received, then the access device may only transmit the third messages through the first and third beams, and not through the second beam. Similarly, if the wireless device only receives the third message through the first and third beams, this may also imply that the second beam is discarded for further communication since no third message is received through it. This example illustrates that the access device can select the preferred / selected beam by sending a third message via the selected beam.

[0477] In an embodiment of the invention that may be combined with other embodiments or used independently, the second messages (e.g. preambles) transmitted from the wireless device may be configured by the access device in a dedicated RRC reconfiguration message, and these preambles (e.g. ZC sequence) are dedicated for the wireless device to use for the repetitive transmission of the second messages (e.g. preambles) in different beams. The wireless device may select one from the set of the configured preambles to use to transmit one or more second messages (e.g., preambles) in different beams.

[0478] In an embodiment of the invention that may be combined with other embodiments or used independently, the wireless device may be configured with a first configuration by the access device in a dedicated RRC reconfiguration message of a dedicated RACH Occasion (RO) Group where one or more ROs may be configured in the RO Group to be used for the UE to transmit one or more2025P00096EP03

[0479] second messages (e.g., preambles) and each RO in the RO group may be used by the UE to transmit one second message (e.g., preamble). The UE may use the configured RO Group to transmit one or more second messages (e.g., preambles) in different beams.

[0480] In an embodiment of the invention that may be combined with other embodiments or used independently, the wireless device may be configured by the access device in a dedicated RRC reconfiguration message of a set of dedicated preambles and a dedicated RACH Occasion (RO) Group where one or more ROs may be configured in the RO Group to be used for the UE to transmit one or more second messages (e.g., preambles) and each RO in the RO Group may be used by the UE to transmit one second message (e.g., preamble). The UE may use the configured preamble and RO Group to transmit one or more second messages (e.g., preambles) in different beams.

[0481] In an embodiment of the invention that may be combined with other embodiments or used independently, the access device may monitor the RACH Occasion (RO) in the RO Group and / or preambles and may determine one or more beam directions to be used for the UE to transmit the subsequent one or more uplink transmissions. The access device may transmit the information of the selected beam direction(s) to the UE in the message (e.g., RAR) after receiving one or more second messages (e.g., preambles). The UE may transmit the subsequent uplink messages using the beam direction(s) indicated by the access device once the UE receives the indication message (e.g., RAR).

[0482] For instance, the access device may transmit third messages through all beams through which second messages were supposed to be received. For instance, if the wireless device transmits second messages through a first, second, and third beam, and only second messages through the first and third beams, are received, then the access device may still transmit the third messages through the first, second and third beams. This assumes that the reception of second messages through the first and third beams are indicative of a second message through the second beam.

[0483] For instance, the access device may determine the best beam upon reception of the one or more second messages, and the access device may transmit the third message only through the one or more best beams, i.e., the selected beams, e.g., beams such that the second messages are received with certain quality (RSRP, RSRQ, etc). This reduces the communication / energy consumption of the access device to transmit the third message.

[0484] For instance, the access device may determine the (one or more) best beams upon reception of the one or more second messages, and the access device may transmit a third message(that may contain an indication of the access device selection (e.g., best beam, and / or one or more preferred beams) by the access device) through two or more beams used by the wireless device when transmitting the one or more second messages. This may allow the access device to indicate the wireless device the best beams upon reception of the one or more second messages and increase the chances of reception of the third messages (due to the transmission of multiple third messages).

[0485] For instance, the access device selection may comprise indicating suitable beams, for instance if wireless device used beams 53, 54, 55, 56, 57 out of 64 to transmit the second messages, and three of the beams are suitable (e.g., 54, 55, 56), the access device may indicate, e.g.,:

[0486] First suitable, and the number of suitable ones (e.g., by transmitting 1, 2 wherein 1 refers to beam number 1 and a total of 2 more beams are suitable);

[0487] Bitmask indicating the selected beams, e.g., Ox 0000 0000 0000 0C10 where the bitmask length in number of bits equals the number of beams used by the access device.

[0488] Bitmask indicating the selected beams, e.g., Ox 0C10 where the bitmask length in number of bits is shorter than the number of beams used by the access device and focuses on the beam indexes used / received.

[0489] For instance, the access device selection may comprise a ranking of the beams used to transmit the one or more second messages.

[0490] For instance, the access device selection may be transmitted by encoding each of the beam identifiers according to its preferences. For instance, if wireless device used beams 54, 55, 56, and 57, the access device may transmit 56, 55, 57, and 54 in preference order.

[0491] For instance, the encoding of the beam identifiers may not be an absolute number related to k, the number of beams used by the access device, but to m, the number of beams used by the wireless device to transmit the one or more second messages. For instance, if wireless device used beams 54, 55, 56, and 57 out of 64 possible beams, the access device prefers 56, 55, 57, and 54 in preference order, the access device may transmit 2, 1, 3, 0. This approach reduces the communication requirements from m*ceil(log2(k)) to m*ceil(log2(m)) where ceil() returns the next positive integer and Iog2 returns the logarithm base 2. In this example, the communication overhead is reduced form 4 bytes to 1 byte.

[0492] For instance, the encoding of the preferred beam identifiers may be done by means of a single identifier. To illustrate this, if m beams are used, for the best beam there are m options, for the second best beam there are m-1 options, for the third best beam there are m-2 options,... so in total there are ml Options. If m=4, this is m!=4*3*2= 24. The number ml can be encoded inceil( Iog2 (m! )) bits that is less than m*ceil(log2(m)) for certain m values, and thus, it may lead to a lower communication overhead. For instance, in above example, 5 bits are required instead of 8 bits.

[0493] For instance, the access device selection may also include metadata, e.g., an indication of how well one or more beams is received, e.g., an indication related to RSRP / RSRQ. This indication may be used by the wireless device to, e.g, perform a final selection of the beam.

[0494] In an embodiment of the invention that may be combined with other embodiments or used independently, the wireless device, upon reception of the reference signals, may determine the need to transmit one or more second messages through one or more beams. When transmitting the one or more second messages, the wireless device may indicate its (current) wireless device selection / preference with regard to the best beams.

[0495] This wireless device selection may indicate and / or be encoded similarly to other embodiments / examples related to the access device selection.

[0496] For instance, the preference may be encoded, e.g., by means of the selection of one or more identifiers transmitted in the one or more second messages in the one or more beams. For instance, if the access device uses k = 64 beams, and the wireless device uses k = 4 beams to transmit the one or more second messages, the wireless device may use four identifiers corresponding to related preambles. The identifier selection may indicate the wireless device selection. For instance, the beam carrying the second message with the highest identifier may be considered the most preferred one. For instance, the beam carrying the second message with the second highest identifier may be considered the second most preferred one, etc.

[0497] In an embodiment of the invention that may be combined with other embodiments or used independently, the access device may express and / or indicate its access device selection to the wireless device. The wireless device may also obtain a wireless device preference from the reception of one or more reference signals (e.g., SSB burst) and / or one or more third messages. The wireless device may determine from the access device selection and / or its own wireless device preference which beam to use for further communication (e.g., Msg3 in RACH).

[0498] In an example, this may be based on the configuration received in the first message (SIB1). For instance, the configuration may indicate whether the wireless device has to use the indication of the access device selection and / or whether the wireless device may select the best beam upon reception of the access device selection in the third message by combining this information with its own wireless device selection and / or whether the wireless device may select the best beam for the transmission of the third message solely based on its own wireless device selection.In an example, if the access device selection ranks beams #2, #1, #0, #3 and the wireless device selection ranks beams #1, #2, #0, #3, the wireless device may (1) select beam #2 if the wireless device is requested to pick up the selection of the access device; or (2) pick up a beam that depends on both selections.

[0499] In an example, the wireless device selection may be based on the received reference signals (only) and it may have been signalled when transmitting the one or more second messages.

[0500] In an example, the wireless device selection may be based on the received one or more third messages / signals.

[0501] In an example, the wireless device selection may be based on the received reference signals and the one or more third messages / signals.

[0502] In an embodiment of the invention that may be combined with other embodiments or used independently, upon reception of the one or more third signals / messages, the wireless device and access device have agreed / can derive / obtain a single beam that can be used to transmit a subsequent message, e.g., Msg3 in the random access procedure. Whether this agreement is achievable at this stage may be indicated by the configuration, e.g., obtained in the first message. This means that the access device may need to monitor a single beam when monitoring / receiving the subsequent message. This means that the access device takes the final decision of the preferred beam for communicating the subsequent message based on the interaction when transmitting the first message(s), reference signals, third messages and receiving the second messages.

[0503] In an embodiment of the invention that may be combined with other embodiments or used independently, upon reception of the one or more third signals / messages, the wireless device and access device may have not agreed / cannot derive / obtain a single beam that can be used to transmit a subsequent message, e.g., Msg3 in the random access procedure. That this agreement is not achievable at this stage may be indicated by the configuration, e.g., obtained in the first message. This means that the access device may need to monitor one or more beams when monitoring / receiving the subsequent message (e.g., Msg3). This means that the wireless device takes the final decision of the preferred beam based on the interaction when receiving the first message(s), reference signals, third messages and transmitting the second messages.

[0504] Fig. 14 describes a procedure according to several embodiments of the invention. Entities 1401, 1402, and 1403 represent the wireless device, the first access device and the third access device, respectively. The arrows represent signals or messages that may be transmitted once or multiple times, the order may also change, and not all signals may be always required. Message 1404represents a first message in which either the first access device 1402 or the third access device provide the wireless device with the first configuration. Signal 1405 represents the regular distribution of reference signals, e.g., synchronization signals by the first access device. The synchronization signals may be transmitted as SSBs in an SSB burst, wherein each of the SSBs is transmitted through a different beam. The wireless device may measure those reference signals, e.g., synchronization signals. Signal 1406 represents the transmission of the second messages (e.g., N second messages through M beams, e.g., N preambles through M beams). Signal 1407 represents the transmission of multiple third messages, e.g., the transmission of multiple copies of the random access response. Messages 1408, 1409, and 1410 represent subsequent messages in the random access procedure, e.g., RRCSetup Request, RRCSetup, and RRCSetupComplete, respectively.

[0505] Fig. 15 schematically describes the communication between the first access device 1500 and the wireless device 1507 using multiple beams. The first access device may have / use one or more wide beams 1505 and 1506. The first access device may have / use one or more narrow beams 1501, 1502, 1503, 1504. Similarly, the wireless device may have one or more wide beams 1511 and / or one or more narrow beams 1508, 1509, and 1510. The first access device may transmit multiple second messages (denoted as 1512) through several of its beams. The wireless device may transmit multiple second messages (denoted as 1512) through several of its beams. The first access device may reply with multiple third messages (denoted as 1513) through several of its beams.

[0506] Fig. 16 schematically describes the transmitted second messages through three beams Beam A, Beam B, and Beam C. Beam B and Beam C may be, e.g., narrow beams and Beam A may be, e.g., a wide beam. Beam A and Beam B may be, e.g., narrow beams and Beam C may be, e.g., a wide beam. The figure illustrates that different beams may transmit second messages with different periodicities. For instance, second messages transmitted through Beam A have a periodicity of time T_2 and second messages transmitted through Beam B have a periodicity of time T_l. It is to be noted that second messages may be transmitted in groups. For instance, 1600 represents a group of two second messages transmitted through Beam B. For instance, 1603 represents a group of six second messages transmitted through all three beams. Second messages transmitted within a group may be repeated with a given periodicity, e.g. 1600 has periodicity T_3. For instance, second messages transmitted through the same beam in group 1603 are repeated with period T_4. For instance, second messages transmitted (independently of the beam used) in group 1603 are repeated with period T_5.2025P00096EP03

[0507] Fig. 17 further illustrates a scenario related to Fig. 15 wherein the wireless device 1507 is moving. At time tO is at location pO and at time tl it is at location pl. This embodiment illustrates a further usage of the transmission of the second messages through multiple beams. When the wireless device remains static at location pO, the choice of transmitting the second messages 1512 through beams 1509 and 1510 is good, but if the wireless device moves that choice may not allow a good connection and transmitting the second messages 1514 through beam 1508 is more suitable. This figure illustrates therefore the advantages of performing the transmission of the second messages through beams that may be suitable for the communication based on the relative movement of the wireless device and first access device. It is to be noted that the relative movement of the devices may be described as a prediction of the beams that are expected to have better performance. For instance, in Fig. 17, attO,pO, beams 1501, 1502, 1503, 1504 are such that beams 1502 and 1503 have the highest signal strength. The analysis of the beam measurements over time may allow predicting that at time tl, pl, beams 1501, 1502, 1503, 1504 are such that beams 1503 and 1504 have the highest signal strength.

[0508] Fig. 18 schematically illustrates some embodiments of the invention wherein 1507 represents a wireless device having a single beam 1510. 1500 represents an access device having three beams 1501, 1502, and 1503. Beam 1502 is the strongest one as measured by wireless device 1507. Wireless device 1507 may determine codeword

[0509] 11000000

[0510] 00011000

[0511] 00000110

[0512] Determining 6 transmission occasions (highlighted as dark rectangles 1800) out of 24 possible transmission occasions 1603. Not selected transmission occasions are indicated as white rectangles. Transmission occasions assigned to beam A (1501), beam B (1502), and beam C (1503) are indicated as 1602, 1601, and 1600 respectively. Transmission occasions are also distributed in time, wherein transmission occasions on the left occur before than transmission occasions on the right.

[0513] Section: pi / 2 BPSK related embodiments

[0514] Further aspects of the invention are described in the context of coverage enhancement for uplink data transmission since the coverage in the cell edge or in non-terrestrial networks is still challenging.In (uplink) transmission, the use of DFT-s-OFDM combined with n / 2-BPSK modulation provides a low peak-to-average power ratio, thereby enabling efficient utilization of the power amplifier. The n / 2-BPSK constellation offers improved robustness against channel impairments and nonlinear distortion relative to higher-order modulations. This approach facilitates extended coverage and reliable transmission for power-constrained devices, including those operating at the cell edge or in non-terrestrial networks.

[0515] The DFT (S0, S1,..., SL-1) of a n / 2-BPSK sequence of even length L has the symmetry property that Sk= (Sm)* whenever k + m mod L = L / 2. When L mod 4 = 2, this implies that the information in each subcarrier is mirrored in a distinct partner subcarrier. When L mod 4 = 0, the information in all but two subcarriers is mirrored in a different subcarrier; the exceptions are the subcarriers with indices L / 4 and 3L / 4, which do not have a distinct partner, but are both real-valued. These symbols are sometimes called pilots.

[0516] In some scenarios, the mirrored symbols may be removed so that only around half of the symbols need to be transmitted. This improves the spectral efficiency of n / 2-BPSK. However, reliability may still be challenging.

[0517] In an embodiment of the invention that may be combined with other embodiments or used independently, since all symbols except two are mirrored, the non-mirrored symbols may be transmitted (e.g., by the transmitted of a wireless device) in two additional carriers. Thus, a n / 2-BPSK sequence can achieved increased reliability or coverage extension since each symbol (or a mirrored version of it as described above) is transmitted twice. In this version, the transmission will have four pilots, i.e., four symbols / carriers that only have the real part of the coefficient.

[0518] In an embodiment of the invention that may be combined with other embodiments or used independently, the transmitter of a wireless device may fill the empty imaginary part of subcarriers L / 4 and 3L / 4 with the (real) value of the other subcarrier, so in subcarrier L / 4 the value SL / 4+ j S3L / 4is transmitted, and in subcarrier 3L / 4 the value S3L / 4+ j SL / 4is transmitted. This improves over previous embodiment since it is not required to use additional carriers.

[0519] In the embodiment it is to be noted that the new values are complex values. Thus, there is no clear reference symbol for the reception. Thus, in an embodiment of the invention that may be combined with other embodiments or used independently, the transmitter of a wireless device may fill may transform / rotate one of the symbols to transform it into a real number so that the n / 2-2025P00096EP03

[0520] BPSK sequence has at least a pilot symbol. The same rotation / transformation may be applied to all symbols. This may facilitate the operation of the receiver.

[0521] In an embodiment of the invention that may be combined with other embodiments or used independently, the uplink receiver may use the symmetry in the transmitted signal by combining the signals in each pair of partner subcarriers, thus enhancing the effective signal-to-noise ratio and further increasing the coverage and / or increasing the reliability of the transmission.

[0522] In an embodiment of the invention that may be combined with other embodiments or used independently, the (uplink) transmitter nulls the transmitted values in up to half of the subcarriers (e.g., this may assume that an L / 2 DFT is performed in the OFDM transmitter instead of an L DFT so that the remaining L / 2 carriers can remain unused, i.e., are nulled). This enhances the spectral efficiency, at the expense of peak-to-average power ratio and receiver SNR.

[0523] In an example, if the transmitter nulls up to half of the coefficients 0,..., L-l (the mirrored coefficients), the transmitter may transmit the non-nulled coefficients rearranged over the L carriers for enhanced performance.

[0524] For instance, if the original coefficients are numbered 0 to L-l, the coefficients that are not nulled are the coefficients with indexes L / 4,..., 3L / 4-1. In this case:

[0525] - for instance, up to L / 4 nulled carriers may be set before and after the up to L / 2 nonnulled carriers (corresponding to the output of the L / 2 OFDM transmitter taking as input the L / 2 nonnulled coefficients) so that the nulled carriers act as guard bands.

[0526] - for instance, a nulled carrier (corresponding to a nulled coefficient) may be placed between every pair of non-nulled carriers, i.e., increasing the subcarrier spacing;

[0527] - for instance, any carrier (coefficient) which has a mirror may be nulled, provided the mirror is not nulled.

[0528] In an example, when half of the coefficients are nulled, the processing of the data stream may be as follows:

[0529] - a block of 2L data symbols is processed.

[0530] - the block of 2L data symbols is divided into two blocks, each of L data symbols. - an L-DFT is performed on each of the two blocks of L data symbols, - half of the coefficients of each of the L-DFT coefficients is redundant / mirrored, and thus, these can be nulled obtaining L / 2 DFT coefficients per block,- the L / 2 DFT coefficients originating from the first block and the L / 2 DFT coefficients originating from the second block may be mixed, e.g., interleaved, e.g., if the L / 2 non-nulled coefficients of the first and second blocks are named F_i and S_i, respectively, the input coefficients may be F0, SO, Fl, SI, F2, S2,..., F_{L / 2-l}, SJL / 2-1}

[0531] - the mixed coefficients are used as input into the OFDM transmitter using as L-Inverse DFT.

[0532] In an alternative embodiment of the invention that may be combined with other embodiments or used independently, the uplink transmitter transmits different information, e.g., parity bits, or data for another purpose, in up to half the subcarriers. For instance, the parity bits may be just the repetition of the mirrored symbols as in previous embodiments. For instance, the parity bits may be derived from an error correction scheme.

[0533] In an embodiment of the invention that may be combined with other embodiments or used independently, the uplink receiver (e.g., of the access device, e.g., base station) indicates, in feedback to the uplink transmitter (e.g., wireless device), the uplink transmitter may adapt the operation of the n / 2-BPSK modulation, e.g., it may require the reduction of the number of subcarriers for subsequent transmissions, and / or how many subcarriers the transmitter may nullify or use for another purpose and / or the transmission of additional carriers duplicating non-mirrored symbols and / or including additional information in the non-mirrored symbols (as explained above).

[0534] In an embodiment of the invention that may be combined with other embodiments or used independently, different configurations for the transmission of an uplink message using a n / 2-BPSK modulation may be applied, e.g., to Msg3 in a random access procedure, e.g., upon performing a random access procedure in which multiple beams are involved, e.g., when a wireless device transmits one or more second messages (e.g., preambles) through one or more beams, and the wireless device receives one or more third messages (e.g., random access response messages) through one or more beams. At this stage, the wireless device may need to transmit Msg3 and it may need to transmit using a suitable modulation, e.g., a n / 2-BPSK modulation in which data symbols are transmitted redundantly, e.g., by using mirrored symbols, and / or may be performed more efficiently (from an spectral point of view) by removing mirrored symbols.

[0535] In an example, the access device may measure one or more parameters of the received second messages, and based on the one or more parameters, it may determine the suitable2025P00096EP03

[0536] modulation, wherein the suitable modulation may be at least one of then / 2-BPSK modulation variants described in embodiments of this invention.

[0537] In an example, the wireless device may determine a suitable configuration, e.g., based on an indication (transmitted by the access device) in one or more of the received third messages and / or measurements of the one or more third messages and / or reference signals.

[0538] Section: parameter signaling for pi / 2 BPSK

[0539] In current 3GPP NR (New Radio) systems, each MCS (Modulation and Coding Scheme) index typically maps to a single combination of modulation order and code rate, ensuring deterministic physical layer processing. However, this rigid mapping limits flexibility when adapting transmission robustness in poor radio conditions. Specifically, n / 2-BPSK is defined in 3GPP TS 38.211 as a low-PAPR modulation option for uplink, but existing signaling does not efficiently indicate whether the wireless device supports it for particular MCS indices. Consequently, base stations cannot dynamically select between n / 2-BPSK and QPSK within a shared MCS index range, leading to inefficient spectral utilization and inconsistent UE capability handling.

[0540] In accordance with a current definition of the inventive concept of this embodiment, this embodiment distinguishes itself by enabling a single MCS index to represent multiple modulation-code-rate pairs, where a signaling mechanism explicitly indicates whether n / 2-BPSK (q=l) or QPSK (q=2) applies, along with per-MCS capability signaling for n / 2-BPSK support. This provides greater flexibility for coverage enhancement and minimizes control signaling overhead.

[0541] In an embodiment of the invention that may be combined with other embodiments or used independently, a wireless device may (be able to) transmit uplink data using an MCS index associated with both n / 2-BPSK and QPSK options. The access device (e.g., gNB) may determine, via downlink control information (DCI), a field pi2_bpsk_indicator that equals 0 or 1. When pi2_bpsk_indicator = 1, the wireless device modulates the data using n / 2-BPSK, i.e., q=l,with a first coding rate, and when pi2_bpsk_indicator=0, it applies QPSK, i.e., q=2, with a second coding rate. The access device may transmit signaling indicating that n / 2-BPSK is (to be) / may be used, allowing proper demodulation. The wireless device may report, in RRC signaling, a bitmap identifying the subset of MCS indices for which it supports n / 2-BPSK.

[0542] In general, the indication may be for other higher order modulation schemes, e.g., higher than QPSK.

[0543] For instance, the indicator may indicate whether 16-QAM with coding rate R or l-Q offset QPSK with coding rate 2R is to be, or may be, used.2025P00096EP03

[0544] In an embodiment of the invention that may be combined with other embodiments or used independently, a wireless device may (be able to) transmit uplink data using an MCS index associated with a plurality of (modulation order, code rate) pairs, e.g, (1, R( 1) ), (2, R(2)), (4, R(4)) and (8, R(8)). These may be encoded in DCI or uplink signaling using a codebook using an appropriate number of bits, e,g. '00' may indicate (1, R( 1)), '01' may indicate (2, R(2 )), '10' may indicate (4, R(4)) and '11' may indicate (8, R(8)). Appropriate number of bits may refer to an approach that minimizes the number of bits. For instance, a bitstring of b bits may be used to indicate (modulation order, code rate) pairs wherein the first bl bits of the b bits indicate the modulation order and the subsequent b2 bits indicate the code rate, wherein b= bl+b2. For instance, if there are N (modulation order, code rate) pairs, then b may be the next integer greater than log2(N). Each b bit value may indicate a specific (modulation order, code rate) pair. The embodiment enables dual-mode operation per MCS index, improving coverage in low-SNR conditions while maintaining backward compatibility.

[0545] In an example, the implementation of the code rate may benefit of embodiments of this invention, e.g., when mirrored pi / 2 BPSK coefficients can be removed and / or kept. In particular, the amount of mirrored coefficients that are removed or kept or added may serve as a coding technique and may be additionally signaled and the MCS index may also account for it.

[0546] In another embodiment variant that may be combined with other embodiments or used independently, an indication may be used to indicate whether modulation and coding scheme are coupled or decoupled. If the indication Q. is set to a predefined value (e.g., 0) or is not present, the modulation and coding scheme are coupled, similar to a legacy scheme. While if the indication Q. is set to a predefined value (e.g., 1 or is present), the modulation and coding scheme are decoupled, so that for each MCS index, one more modulation indicator z may be expected indicating the modulation scheme that is used or to be used..).

[0547] As a matter of clarification, in an example, this indication Q. (or also an indication as in other examples, clarifications, e.g., z below) may be included in a SIB, e.g., SI Bl, an RRC message, or a DCI message.

[0548] As a matter of clarification, in an example, this modulation indicator z may apply to a complete MCS table, wherein each MCS index may have one or more modulation values, and the indication may indicate which of the modulation values may be applicable. For instance, given the following table, a modulation indicator z=0 may indicate modulation orders q={l,l, 1,2,2} for MCS indices = {0,1, 2, 3, 4} while indication z= 1 may indicate q={2,2,2,4,4} for MCS indices = {0,1, 2, 3, 4}. For2025P00096EP03

[0549] instance, an modulation indicator z= 0 may indicate a configuration suitable to achieve low PAPR, while a modulation indicator z= 1 may indicate a configuration suitable to achieve higher spectrum efficiency.

[0550] MCS index Modulation order q Code rate x 1024

[0551] 0 1,2 240 / q

[0552] 1 1,2 314 / q

[0553] 2 1, 2 386 / q

[0554] 3 2,4 1360 / q 4 2, 4 1512 / q

[0555]

[0556] As a matter of clarification, in an example, the indication Q. may apply to a subset of the indices in the MCS table, for instance, in above table the indication Q=0 may indicate that only MCS indices {0,1,2} may be used with two modulation values, while MCS indices {3, 4} may only be used with a default modulation value, e.g., q=2. The MCS index up to which two modulation values may be used may be obtained from a specification or from earlier signalling.

[0557] In another embodiment variant that may be combined with other embodiments or used independently, the signaling of Q. is performed through a second signaling (e.g, MAC-CE (Medium Access Control Control Element), or RRC or SIB) rather than a first signaling (e.g., DCI), thereby reducing the size of the first signaling (e.g., DCI field size) and preserving spectral efficiency. The wireless device may preconfigure or indicate, e.g., via a third signaling (e.g., RRC signaling, (a message exchanged during) initial random access procedure), its n / 2-BPSK support for certain MCS levels (one or more MCS indices, e.g., up to a given MCS index), allowing the access device to infer possible modulation choices.

[0558] As a matter of clarification,

[0559] the access device may transmit to a wireless device via a second signaling (e.g., MAC CE, RRC or SIB, e.g., SI Bl) whether modulation and coding scheme are coupled or decoupled;

[0560] the wireless device may indicate to the access device via a third signaling its n / 2-BPSK support for certain MCS levels; and

[0561] the access device may transmit to the wireless device via a first signaling (e.g., DCI) the modulation and coding scheme to be used by the wireless device in a subsequent transmission, e.g., an uplink transmission.

[0562] It is to be noted that the third signaling, in which the wireless device indicates its modulation order support is required by an access device to differentiate between legacy devices,2025P00096EP03

[0563] which may support two modulation order values only for the first two MSC entries, and non-legacy devices that may support two or more modulation order values for up to N MCS entries, with N>2. The indication in the third signaling may allow differentiating the behavior of a legacy and non-legacy device.

[0564] The indication in the third signaling may be explicit, or implicit, e.g., encoded in a certain field in Msg3 of the random access procedure.

[0565] In another embodiment variant, the access device may indicate its support for pi / 2-BPSK for all MCS indices up to a maximum value, for instance 'up to MCS=6' would indicate that MCS indices 0, 1, 2, 3, 4, 5, and 6 have a pi / 2-BPSK variant.

[0566] This embodiment increases the flexibility and / or may reduce downlink control overhead while supporting dynamic adaptation of modulation type.

[0567] In another embodiment variant that may be combined with other embodiments or used independently, the wireless device may dynamically switch between modulations, e.g., n / 2-BPSK and QPSK, within a wireless procedure, e.g., within a HARQ. process, based on instantaneous channel quality metrics. The access device may use uplink channel quality indication (CQ. I ) reports to determine the modulation, e.g., if n / 2-BPSK should be used, and signals the modulation indicator z.

[0568] In another operation, the wireless device may maintain a capability table mapping MCS indices to modulation options and may report it during the capability exchange. This allows the access device to select MCS and modulation options suitable for the wireless device.

[0569] Additionally or alternatively, the wireless device may take the decision on which modulation scheme to use based on the measured and reported uplink CQI, e.g., based on a configuration. The wireless device may report the configuration used for the transmission of a second uplink message, e.g. the modulation indicator by means of a first uplink message (e.g., the second messages / preambles, or Msg3 in the random access procedure) encoded using a first set of (default) transmission parameters (e.g., pi / 2 BPSK). This embodiment enhances link robustness under fading conditions, ensuring consistent throughput with minimal retransmissions.

[0570] In an example, the wireless device may use a modulation and coding scheme (MCS) index for which multiple combinations of modulation depth and code rate are defined. For instance, when using MCS index 0, the modulation depth may be q = 1 or 2, and the corresponding code rate isR = (240 / q / 1024). When q = 1, the modulation is n / 2-BPSK, which gives signal waveforms with a lower peak-to-average-power ratio (PAPR) than the QPSK waveforms for q = 2. A lower PAPR is advantageous in operating the power amplifier. The wireless device may indicate for which MCS indices it will use n / 2-BPSK modulation.

[0571] In an embodiment of the invention that may be combined with other embodiments or used independently, an access device (e.g., the first access device) may provide a configuration to a wireless device; or the wireless device may obtain the configuration via other means, e.g., retrieve it from memory.

[0572] In an example, the access device (e.g., the first access device) may distribute the configuration in a SIB, e.g., SI Bl, or RRC message.

[0573] In an example, a third access device may provide the configuration related to another access device, e.g., the first access device, via an RCC message, so that the wireless device can use said configuration when accessing the first access device.

[0574] The configuration may encode the maximum MCS / allowed MCSswith applicable pi / 2 BPSK and / or the default MCS, e.g., in a given communication procedure, e.g., random access. The configuration may also include other helper data, e.g., type and / or coefficients of non-transparent filters to be used as per other embodiments), e.g.:

[0575] Indication whether MCS and modulation are (de)coupled

[0576] A modulation index z for indicating which modulation scheme is being used or is to be used for a given MCSC that is decoupled from modulation, e.g. z=0 / 1 for modulation scheme of lowest order.

[0577] Which MCS indices support n / 2-BPSK (UE capability bitmap)

[0578] Parameters controlling mirrored-subcarrier usage

[0579] Rules for symbol duplication, nulling, or rearrangement

[0580] Parameters controlling spectrum extension / truncation

[0581] Parameters selecting specific low-PAPR sequences / codebooks

[0582] The wireless device may select in an initial communication, e.g., when transmitting second messages, a default value. The wireless device may also indicate via an uplink message the configurations that it supports. This knowledge may allow the access device to select MCS configurations supported by the wireless device, and to instruct the wireless device to use one of the MCS configurations supported by the wireless device.In general, it is proposed a procedure performed by a wireless device for low PAPR communication comprising:

[0583] receiving via a first signaling and / or obtaining, by the wireless device, a modulation and coding (MAC) indication whether

[0584] (1) modulation information and coding information for one or more modulation and coding scheme (MCS) indices are coupled or decoupled; and / or

[0585] (2) modulation information for one or more modulation and coding scheme (MCS) indices, and

[0586] receiving, by the wireless device, via a third signaling an assignment of a modulation and coding scheme for a subsequent transmission.

[0587] In general, the previous procedure further comprises, prior to the reception of the third signaling,

[0588] transmitting, by the wireless device, a second signaling indicating the wireless device support for pi / 2-BPSK for one or more modulation and coding scheme indices.

[0589] In general, it is proposed a procedure performed by an access device for low PAPR communication comprising:

[0590] transmitting, by the access device, via a first signaling a modulation and coding (MAC) configuration whether

[0591] (1) modulation information and coding information for one or more modulation and coding scheme (MCS) indices are coupled or decoupled; and / or

[0592] (2) modulation information (index) for one or more modulation and coding scheme (MCS) indices, and

[0593] and

[0594] transmitting, by the access device, via a third signaling an assignment of a modulation and coding scheme for a subsequent transmission.

[0595] In general, the previous procedure further comprises, prior to the transmission of the third signaling,

[0596] receiving, by the access device, a second signaling indicating the wireless device support for pi / 2-BPSK for one or more modulation and coding scheme indices.2025P00096EP03

[0597] In general, it is proposed the previous procedures:

[0598] - wherein the first signaling is transmitted via a SIB1 or RRC message; and / or - wherein the MAC configuration indicates a maximum MCS index up to which n / 2-BPSK is applicable; and / or

[0599] - wherein modulation information for one or more modulation and coding scheme (MCS) indices is 1 bit long, and indicates for two or more MCS entries whether a high PAPR modulation or a low PAPR modulation is used, and / or

[0600] - wherein modulation information for two or more modulation and coding scheme (MCS) indices is 1 bit long, and indicates whether a high PAPR modulation or a low PAPR modulation is used for each and every MCS entries for which two modulation schemes are applicable, and / or - wherein modulation information for two or more modulation and coding scheme (MCS) indices is 1 bit long, and indicates whether a high PAPR modulation or a low PAPR modulation is used for each and every MCS entries for which two modulation schemes are applicable, wherein the two or more MCS indices jointly have three or more modulation orders, and / or

[0601] - wherein the MAC configuration indicates the modulation order to be used with one or more MCS indices of an MCS table; and / or

[0602] - wherein the MAC configuration configures whether modulation order (e.g., n / 2-BPSK) selection is performed by the wireless device, the access device, or both; and / or

[0603] - wherein the MAC configuration configures whether n / 2-BPSK is applied to uplink and / or downlink transmissions; and / or

[0604] - wherein the MAC configuration configures one or more fixed spectral-efficiency thresholds used to determine the applicability of one or more modulation orders (e.g., n / 2-BPSK, QPSK, etc) for the assigned MCS index; and / or

[0605] - wherein the MAC configuration configures a table comprising multiple available modulation-coding pairs per MCS index, including at least one pair corresponding to n / 2-BPSK; and / or wherein the MAC configuration configures a decoupled MCS mode in which a modulation-order indicator is provided independently of a coding-rate and / or code scheme indicator; and / or

[0606] - wherein the wireless device stores the MAC configuration in first signaling in a configuration memory and applies the MAC configuration for subsequent uplink transmissions without further first signaling; and / or

[0607] - wherein the second signaling comprises a bitmap indicating a modulation order (e.g., n / 2-BPSK) support for a plurality of MCS indices; and / or2025P00096EP03

[0608] - wherein the second signaling comprises an indication indicating a modulation order (e.g., n / 2-BPSK) support for a plurality of MCS indices (e.g., up to a given MCS index); and / or

[0609] - wherein the second signaling identifies a set of MCS indices for which the wireless device supports both two or more modulations (e.g., n / 2-BPSK and QPSK), enabling dual-mode operation.

[0610] - wherein the second signaling indicates whether the wireless device supports n / 2-BPSK operation for one or more communication procedures (e.g., HARQ retransmissions, downlink transmission); and / or

[0611] - wherein the third signaling comprises an indicator identifying whether modulation order and coding rate / scheme are selected jointly or independently; and / or

[0612] - wherein the third signaling comprises a bitstring identifying one of a plurality of modulation-coding pairs associated with the assigned MCS index; and / or

[0613] - wherein the third signaling comprises a parameter indicating whether mirrored n / 2-BPSK coefficients are kept, removed, or added for the uplink transmission; and / or

[0614] - wherein the third signaling indicates that a fallback modulation order, including n / 2-BPSK, is to be used in case of degraded channel conditions; and / or

[0615] - wherein the first signaling and the third signaling are transmitted in the same message; and / or

[0616] - wherein the assigned modulation and coding scheme in the third signaling is selected in accordance with the wireless device's indicated modulation (e.g., n / 2-BPSK) support when the MCS index is decoupled; and / or

[0617] - wherein the wireless device determines whether to apply n / 2-BPSK or QPSK based on an additional modulation-type indicator included in the third signaling; and / or

[0618] - wherein the third signaling is transmitted via a DCI message; and / or - wherein the third signaling indicates the selection of pi / 2-BPSK; and / or - wherein the subsequent transmission is an uplink transmission; and / or - wherein the subsequent transmission is a downlink transmission; and / or

[0619] - wherein the wireless device dynamically selects n / 2-BPSK or QPSK for the scheduled uplink transmission based on an uplink channel-quality metric.

[0620] Section: application to random access procedure

[0621] In an embodiment of the invention, a message such as a preamble in a random access procedure maybe transmitted using an an l / Q-offset DFT-s-OFDM scheme with a partial overlap of the some of the carriers. If two wireless devices select two preambles that are allocated overlappingresources, the receiver (e.g., access device) can decode jointly. This approach can allow transmitting messages such as preambles with a modulation exhibiting a lower PAPR, while still enabling efficient decoding at the receiver even in the case of overlapping reception.

[0622] Section: generation of low PAPR sequences

[0623] A DFT-spread OFDM (DFT-s OFDM) transmitter is a variant of the traditional OFDM transmitter, widely used in modern wireless communication systems such as LTE and 5G NR, especially for uplink transmissions. The transmitter requires several signal processing steps, including:

[0624] a. Input Data and Modulation: The transmitter starts with a block of input data bits. These bits are mapped to modulation symbols (e.g., QPSK, 16QAM, n / 2-BPSK).

[0625] b. Discrete Fourier Transform (DFT) Spreading: The sequence of modulation symbols is passed through a DFT block. The DFT operation spreads each symbol across all subcarriers, introducing correlation between them. This is the key step that gives DFT-s OFDM its single-carrier-like properties and reduces PAPR.

[0626] c. Subcarrier Mapping: The DFT output is mapped onto a subset of the available OFDM subcarriers. This mapping can be localized (adjacent subcarriers) or distributed (interleaved subcarriers), depending on system design.

[0627] d. Inverse Fast Fourier Transform (IFFT): The mapped frequency-domain symbols are then transformed back to the time domain using an IFFT, just like in conventional OFDM. This step generates the composite time-domain signal to be transmitted.

[0628] e. Cyclic Prefix Insertion: A cyclic prefix (CP) is added to each OFDM symbol to mitigate inter-symbol interference caused by multipath propagation.

[0629] f. Digital-to-Analog Conversion and RF Processing: The signal is converted to analog, upconverted to the carrier frequency, amplified, and transmitted over the air.

[0630] A key research question is how to reduce further the PAPR in a DFT-s OFDM transmitter.

[0631] In an embodiment of the invention that may be combined with other embodiments or used independently, not all input data bitstrings (step a) will lead to a time-domain signal with a low PAPR. Certain input data bitstrings may lead to time-domain signals with a lower PAPR. Thus, a wireless device may have a list of low PAPR data bitstrings, e.g., a list of length 2n. Each bitstring may have length m, e.g., m bits. This means that a raw input data bitstring of length n bits may be mapped to an input data bitstring of length m bits.2025P00096EP03

[0632] If the raw input data bitstring has length longer than n bits, e.g., N bits, the raw input data bitstring may be divided into segments of n bits, and each of them mapped to a low PAPR input data bitstring of length m bits. The wireless device may be configured with the list of low PAPR data bitstrings. An illustrative list may be as follows

[0633] n-bit raw input data bit strings m-bit low PAPR input data bit strings

[0634] 000 1001100

[0635] 001 0101001

[0636]

[0637] In a Repeated-and-Offset QPSK (RO-QPSK) modulation scheme, offset QPSK (OQPSK), traditionally used in single-carrier satellite systems, is adapted to the DFT-s-OFDM context. The technique involves repeating and offsetting QPSK symbols in a specific pattern before DFT spreading. The repeating and offsetting is performed as illustrated by means of Fig. 19 wherein each row corresponds to a QPSK symbol, in particular, the l-branch and Q-branch, wherein l-branch and Q-branch refer to the In-phase and Quadrature components, respectively, which are two orthogonal signal channels used to transmit data simultaneously. The RO-QPSK scheme achieves a maximum PAPR on the order of 2 dB, which is significantly lower than conventional DFT-s-OFDM with standard QPSK or n / 2-BPSK modulation. However, this scheme can be further improved:

[0638] For instance, the repetition scheme is limited to two repetitions, however, a higher repetition scheme can be enabled. Thus, in an embodiment of the invention that may be combined with other embodiments or used independently, a higher repetition scheme is achieved by adding symbols. For instance, a 2krepetition scheme can be achieved by transmitting in each branch the addition of up to k input bits. For instance, a 6 repetition scheme is achieved by transmitting in each branch 1 bit or the addition of two bits, e.g., as follows:

[0639] Bits

[0640] l-branch Q-branch

[0641] bO b(N-l)+bl

[0642] Conj(bO) Conj(b(N- 1 )+b 1 )

[0643] b()+b2 bl

[0644]

[0645] 2025P00096EP03

[0646] Conj(b0+b2) Conj(bl)

[0647] b2 bl+b3

[0648] Conj(b2) Conj(bl+b3)

[0649] b2+b4 b3

[0650] Conj(b2+b4) Conj(b3)

[0651] b3+b5

[0652]

[0653] In this and other similar tables in this invention, the input bits are denoted bO, bl,... and are mapped to the components in the l-branch and Q-branch of (QPSK) modulation symbols. The first modulation symbol appears in the first row, the second modulation symbol appears in the second row, and so on.

[0654] The l-branch includes components from even bits of the input data bO, b2, b4,... and the Q-branch includes components from the odd bits of the input data bl, b3, b5,... The values of the l-branch and Q-branch have a pre-defined offset, in this case, the offset is such that when the l-branch has a value that depends on a single bit of the input data, the Q-branch has a value that depends on two bits of the input data.

[0655] In this and other examples, Conj(a) may be a function that returns 1-a. In some cases, Conj(a) may return the complex conjugate of a. The operator + in a+b may refer to an operation between the inputs a and b, e.g., it may refer to a binary addition.

[0656] In the scheme illustrated by means of previous table, each input bit is transmitted in six different symbols. This increases the redundancy and it also reduces the "jumps" between symbol.

[0657] In general, a low PAPR signal may be obtained by transmitting each input symbol in k symbols of a low PAPR signal. The higher k is, the lower the PAPR of the low PAPR signal is. Fig. 23 schematically illustrates the achievable PAPR for different repetition factors, e.g., 2, 4, 6, 8, and 16. The RO-QPSK scheme for repetition factor four may be as follows:

[0658] Bits

[0659] I-branch Q-branch

[0660]

[0661] 2025P00096EP03

[0662] bO Conj(b(N-l))

[0663] Conj(bO) bl

[0664] bO Conj(bl)

[0665] Conj(bO) bl

[0666] b2 Conj(bl)

[0667] Conj(b2) b3

[0668] b2 Conj(b3)

[0669] Conj(b2) b3

[0670] b(N-2) Conj(b(N-3))

[0671] Conj(b(N-2)) b(N-l)

[0672] b(N-2) Conj(b(N-l))

[0673] Conj(b(N-2)) b(N-l)

[0674]

[0675] In this example, the l-branch and Q-branch have a predefined offset, e.g., of value n=l. This means a new input bit is introduced in component k of the Q-branch, if a new input bit was introduced in component k-n of the Q-branch. In general, n could also be 2,...,k-l for a number of repetitions k. Odd shifts make sure that consecutive (QPSK) symbols are different.

[0676] In above schemes and examples, the repetitions are introduced in such a manner that the input low PAPR signal is not symmetric. In an embodiment of the invention that may be combined with other embodiments or used independently, repetitions can be introduced in such a manner that the input low PAPR signal is symmetric. This low PAPR signal when used as input to the DFT would result in a frequency domain signal that would have redundant components. This can be used for increasing reliability or to avoid spectrum extension. An approach to create a symmetric input low PAPR signal may be as follows:

[0677] Bits

[0678]

[0679] 2025P00096EP03

[0680] l-branch Q-branch

[0681] b(0) Conj(b(N-1))

[0682] Conj(bO) bl

[0683] b2 Conj(bl)

[0684] Conj(b2) b3

[0685] b(N-2) Conj(b(N-3))

[0686] Conj(b(N-2)) b(N-l)

[0687] Conj(b(N-2)) b(N-l)

[0688] b(N-2) Conj(b(N-3))

[0689] Conj(b2) b3

[0690] b2 Conj(bl)

[0691] Conj(bO) bl

[0692] bO Conj(b(N-l))

[0693]

[0694] In this exemplary construction, the first (Q. PSK) modulation symbol equals the last (Q. PSK) modulation symbol in the table. In general, (Q. PSK) modulation symbol s equals (Q. PSK) modulation symbol M-l-s, where M is the length of the sequence (number of rows in the table) and s = 0,..., M / 2.

[0695] In some schemes the modulation scheme is limited to QPSK-, but it may also be useful to obtain such a scheme for higher order modulation schemes, e.g., 16 QAM. In an embodiment of the invention that may be combined with other embodiments or used independently, a higher modulation scheme is supported by encoding each input bit in multiple high order modulation symbols. An input bit may influence the l-branch or Q-branch depending on the input bit index. An input bit may influence a specific bit of the l-branch or Q-branch depending on the input bit index. This is, e.g., illustrated by means of the following table mapping input bits to the corresponding values in2025P00096EP03

[0696] the I- and Q-branches in 16-QAM. Here the Conj () function may act on both two bits, for instance by negating both bits and / or on the result of the operation.

[0697] In 1p bit of the input data sequence are mapped to bits in each constellation p Bits

[0698] l-branch Q-branch

[0699] bO. bl Conj(b(N-2). b(N-l))

[0700] Conj(b(0). b1 ) b2. b3

[0701] b4. b5 Conj(b2. b3)

[0702] Conj(b4. b5) b6. b7

[0703] b8. b9 Conj(b6. b7)

[0704] Conj(b8. b9) b10. b11

[0705] b(N-4). (N-3) Conj(b(N-6). b(N-5))

[0706] Conj(b(N-4). b(N-3) b(N-2). b(N-l)

[0707]

[0708] In this scheme, each input bit is transmitted in two different 16 QAM symbols. Input bit b is transmitted in the l-branch if b mod 4 = 0 or 1, and in the Q-branch if b mod 4 = 2 or 3. Input bit b is transmitted as the first bit in the l-branch if b mod 4 = 0, and in the second bit if b mod 4 = 1.. Input bit b is transmitted as the first bit in the Q-branch if b mod 4 = 2, and in the second bit if b mod 4 = 3.

[0709] Fig. 24 schematically illustrates the PAPR achieved in a 16-QAM scheme using a variable number of repetitions showing that for two repetitions the improvement is of around 3 dB.

[0710] It is to be noted that other QAM-k schemes, with k>4 can benefit of such scheme. In QAM-schemes with k>4, each constellation point is labeled by means of 3 bits or more, e.g., in QAM-6. Then in QAM-k schemes, three or more input bits may be used to determine each QAM-k symbol.

[0711] In some examples, the input bits may be mapped to the 3 or bits of each constellation point by means of a sliding window.2025P00096EP03

[0712] In an embodiment of the invention that may be combined with other embodiments or used independently, the number of sequences may be further increased by swapping the input bits in the I- and Q-branches, e.g., for any of the schemes illustrated by means of Fig. 19 or the last two tables above, even input bits may be used in the Q-branch, and odd input bits may be used in the I-branch.

[0713] The sequences generated by above schemes (e.g., as illustrated by means of Fig. 14) have low PAPR. However, there are a few of them. Thus, in an embodiment of the invention that may be combined with other embodiments or used independently, an approach to obtain and use more sequences with even lower PAPR may be to generate multiple sequences (e.g., by introducing small errors), and select the sequence with the lowest PAPR. For instance, the Fig. 20, left illustrates a modulation scheme as in 19 while Fig. 20, right, illustrates a modulation scheme as in Fig. 19 but introducing an error, namely, instead of using symbol (b2, Conj(bl)), the symbol (Conj(b2, bl) is used. This single error can also be denoted as single flip. The wireless device transmitting the input bits may obtain both sequences, and determine which one of them leads to a lower PAPR, and select the one that has lower PAPR. A receiver can decode the sequence without problems because it can determine whether the sequence has an error or not, and if an error is detected, it can be corrected.

[0714] Fig. 21 illustrates the PAPR that is achieved by means of an RO-QPSK N=64 modulation scheme (i.e. with sequences of length N=64) as illustrated in Fig. 19 vs the PAPR achievable by means of a modulation scheme based on the selection of the sequence with the lowest PAPR out of N+l=65 possible sequences (as illustrated in Fig. 20). In this example, the N+l=65 sequences are the original sequence (without bit flips) and the 64 alterna sequences with a bit flip in any of the 64 positions.. In some cases, the transmitter may flip a symbol in one out of m fixed positions (with m less or equal than N), or not flip a symbol at all, leading to m+1 possible sequences, and the transmitter selects the sequence with lowest PAPR. e.

[0715] In an embodiment of the invention that may be combined with other embodiments or used independently, the positions of a sequence, e.g., a RO-QPSK N=64 sequence, are partitioned into v groups, where v is at least two, and bit flips can be done in one or more groups, e.g., only one group.

[0716] It is to be noted that if flips can be done in only one group, there are less potential sequences than before.2025P00096EP03

[0717] It is to be noted that the choice of the group may be used to transmit some bits. This does require that an actual flip is being made in that group. The receiver may determine in which group the flip is performed to determine the transmitted bits. The transmitted bits may correspond to the group index.

[0718] Additionally or alternatively, the same group may always be selected for (potentially) changing / adapting / improving the PAPR, this may lead to less potential sequences, so less gain in PAPR, but this may be less complex to implement. For instance, in a RO-QPSK N=64, there can be two groups of N-k = 56 and k = 8 symbols. Flips in the group with k symbols may be used to select sequences with lower PAPR while the group with N-k symbols may be used for data transmission.

[0719] Additionally or alternatively, the wireless device may perform one or more flips, e.g., at most one flip, in multiple groups, in an option such that symbols from different groups are not influenced by any bit that is to be modulated. This may lead to more opportunities and thus to potentially lower PAPR.

[0720] For instance, Fig.22 illustrates symbols similar to Fig. 20, right, e.g., for RO-QPSK N=64. However, in this example, the symbols are grouped in k groups of N / k=4 symbols each. If the wireless device needs to transmit a message related to group g (e.g., the information to be transmitted is g, and thus the selected group is group g), the wireless device may encode the information with any of the RO-QPSK sequences that have one or more flips in group g. For instance, in the context of Fig. 22, group g=0, and thus, the flip can be in the first and / or, second and / or, third and / or fourth symbols. The wireless device may determine the estimated PAPR for each of those sequences, and select the sequence (with one or more flips in the selected group) with the lowest PAPR. In this example, that sequence is the one that flips the third symbol (Conj (b2), bl).

[0721] It is to be noted that in this example the symbols in a group are selected to be consecutive to each other, but other arrangements may be feasible, e.g., the symbols in a group may be selected to be in steps of L / k symbols.

[0722] As described above, a DFT-s OFDM transmitter takes input data, feeds the input data in the DFT, and the DFT output is taken as input of an IFFT that performs the carrier mapping:

[0723] a. Input Data and Modulation: The transmitter starts with a block of input data bits. These bits are mapped to modulation symbols (e.g., QPSK, 16QAM, n / 2-BPSK).

[0724] b. Discrete Fourier Transform (DFT) Spreading: The sequence of modulation symbols is passed through a DFT block. The DFT operation spreads each symbol across all subcarriers, introducing correlation between them. This is the key step that gives DFT-s OFDM its single-carrier-like properties and reduces PAPR.2025P00096EP03

[0725] c. Subcarrier Mapping: The DFT output is mapped onto a subset of the available OFDM subcarriers. This mapping can be localized (adjacent subcarriers) or distributed (interleaved subcarriers), depending on system design.

[0726] d. Inverse Fast Fourier Transform (IFFT): The mapped frequency-domain symbols are then transformed back to the time domain using an IFFT, just like in conventional OFDM. This step generates the composite time-domain signal to be transmitted.

[0727] Embodiments of this invention may be applied to step a. so that normal input data is transformed into a low PAPR input sequence that is fed into the DFT.

[0728] It is to be noted that depending on the properties of the low PAPR input sequence (e.g., depending on whether the repetition introduces a symmetric in the signal), the DFT signal will exhibit certain properties, e.g., conjugate symmetry. This means that only a fraction of the coefficients may need to be transmitted.

[0729] Alternatively, the receiver may exploit this symmetry to improve the reception of the signal (since the receiver knows that the coefficients are, e.g., symmetric or conjugate symmetric).

[0730] Embodiments of this invention may also be applicable to the output of the DFT prior to the subcarrier mapping to further spread the output of the DFT.

[0731] Section: spectrum extension and spectrum truncation, application to l / Q -offset DFT-s OFDM

[0732] In some scenarios, uplink low-PAPR schemes may be evaluated with spectrum extension and spectrum truncation as summarized in 3GPP Tdoc Rl-2509531.

[0733] The embodiments described in this invention may be evaluated with spectrum extension. For instance, if in a RO-QPSK N=64 with k=4 repetitions as illustrated in one of the tables above, to keep the same data rate, spectrum extension (i.e., additional carriers) may be required, wherein the spectrum extension is dependent on k, the number of repetitions mapping the input data sequence to the low-PAPR input data sequence.

[0734] A scheme that may be used for spectrum extension / truncation is l / Q-offset DFT-s-OFDM that can be considered as an extension of a pi / 2 BPSK for higher order modulations. In this scheme, an M-point DFT is applied to to M QAM symbols. The DFT output is separated into real and imaginary components, forming two sequences Xr [k] and Xi [k]. Both sequences are extended from M to N (> M) points, introducing frequency redundancy. The extended real and imaginary parts are combined with a half-pulse shift (phase rotation / offset) to form the final frequency-domain sequence Xo[k]. Finally, Xo[k] is mapped to subcarriers, frequency domain spectral shaping (FDSS) is applied (bymeans of transparent or not transparent filters), IFFT and CP addition is performed to generate the time-domain signal.

[0735] This scheme benefits from the spectrum expansion technique described in this invention:

[0736] In an embodiment of the invention that may be combined with other embodiments or used independently, non-transparent filter embodiments may apply to different low-PAPR schemes with spectrum extension and / or truncation.

[0737] Section: draft clauses

[0738] In general, in a first clause, Clause 1, it is proposed a method for operating a wireless device, comprising the steps of:

[0739] Obtaining, by the wireless device, configuration information for one or more communication parameter with one or more target access devices;

[0740] determining, by the wireless device, one or more values for the one or more communication parameters with a preferred target access device based on the configuration information; and

[0741] communicating, by the wireless device, a first message with the preferred target access device using the one or more values for the one or more communication parameters.

[0742] / / clauses related to low PAPR sequences

[0743] In general, in a second clause (Clause 2), it is proposed the method of clause 1, wherein the configuration information for one or more communication parameters comprises a configuration information for low PAPR sequences.

[0744] In general, in a third clause (Clause 3), it is proposed the method of clause 2, wherein the one or more values comprise a low PAPR sequence.

[0745] In general, in an fourth clause (Clause 4), it is proposed the method of clauses 2 and 3, wherein the configuration comprises a codebook mapping an input data bitstring sequence into a low PAPR input sequence, wherein the low PAPR input sequence is used as input to the DFT in a DFT-s OFDM transmitter.In general, in a fifth clause (Clause 5), it is proposed the method of clauses 2 and 3, further comprising obtaining a low PAPR input sequence by mapping an input symbol into k low PAPR symbols in the low PAPR input sequence, with k>2.

[0746] In general, in a sixth clause (Clause 6), it is proposed the method of clauses 2 and 3, further comprising obtaining a low PAPR input sequence by mapping an input symbol into a component of a symbol of a k-QAM modulation scheme, with k>4, wherein each symbol of a k-QAM modulation system has three or more components.

[0747] In general, in an seventh clause (Clause 7), it is proposed the method of clauses 2 and 3, further comprising obtaining a first low PAPR input sequence and a second low PAPR input sequence, wherein the l-branch and Q-branch of the first low PAPR input sequence correspond to the Q-branch and l-branch of the second low PAPR input sequence.

[0748] In general, in an eighth clause (Clause 8), it is proposed the method of clauses 2 and 3, further comprising

[0749] obtaining, by the wireless device, a first low PAPR input sequence and a second low PAPR input sequence, wherein at least one of the first low PAPR input sequence and the second low PAPR input sequence is obtained by introducing a bit flip,

[0750] selecting, by the wireless device, a selected low PAPR input sequence between the first and second low PAPR input sequences, and

[0751] communicating, by the wireless device, based on the selected low PAPR input sequence.

[0752] In general, it is described a method for performing a data transmission using a n / 2-BPSK modulation that may be implemented in a transmitter, wherein the method comprises:

[0753] - obtaining an adaptable configuration for adaptable n / 2-BPSK transmission;

[0754] - obtaining an L symbol data stream;

[0755] - modulating the L symbol data stream into a n / 2-BPSK modulation scheme into an L symbol modulated stream;

[0756] - obtaining L DFT symbols by performing an L DFT on the L symbol modulated stream; - mapping the L DFT symbols into M carriers according to the adaptable configuration.

[0757] In general, it is described a method for performing a data reception using a n / 2-BPSK modulation that may be implemented in a receiver, wherein the method comprises:

[0758] - obtaining an adaptable configuration for adaptable n / 2-BPSK transmission;

[0759] - mapping M carrier symbols into L DFT symbols according to the adaptable configuration;2025P00096EP03

[0760] - obtaining an L symbol modulated stream by performing an L IDFT on the L DFT symbols;

[0761] - performing n / 2-BPSK demodulation of the L symbol modulated stream into an L symbol data stream;

[0762] In general, the adaptable configuration allows for one or more of:

[0763] Increasing the spectral efficiency by removing mirrored DFT symbols (M < L); Increasing coverage / reliability by exploiting mirrored DFT symbols to improve reception (M = L);

[0764] Increasing coverage / reliability by introducing copies of the non-mirrored DFT symbols (M >=L).

[0765] Further aspects of the invention are described in the context of massive random access and coverage enhancements.

[0766] In massive random access, the goal is to increase the number of wireless devices that perform random access simultaneously. This is important since future wireless networks may require, e.g., supporting increasing number of wireless devices and / or supporting non-terrestrial devices covering a large area, etc.

[0767] Coverage enhancements aim at ensuring the communication between a wireless device and an access device can be established (e.g., during random access) and / or is feasible despite distance between wireless and access devices, low strength and / or quality of the exchanged signals.

[0768] In cellular networks, random access is performed by transmitting a second message, e.g., preamble, to the network / access device. This comprises several steps.

[0769] Determining the preamble: The preamble is a carefully chosen signal. In a typical cell (e.g., in LTE), there are 64 possible preambles. These are derived from specific sequences with properties explained below. The wireless device learns about these preambles from the access device, which broadcasts configuration details, e.g., in. SIB (or first message). This includes parameters like the root sequence index and zeroCorrelationZoneConfig, which define the set of preambles available in that cell. The wireless device may perform contention-based or contention-free random access. In Contention-Based Random Access, the wireless device (UE) randomly picks one of the 64 preamble indices. This randomness can lead to multiple wireless devices choosing the same preamble, causing a potential collision (resolved later in the procedure). In Contention-Free Random Access, the access device assigns a specific preamble index to the wireless device, typically for scenarios like handovers, where the network needs to ensure a dedicated signal. For this explanation, we'll focus on the contention-based case, as it's more common. So, the wireless device starts by selecting a preamble2025P00096EP03

[0770] index— say, number 42 out of the 64 options— based on a random choice in the contention-based scenario.

[0771] Computing the preamble: Once the wireless device has a preamble index, it needs to generate the actual signal. The preamble is based on a Zadoff-Chu sequence, a complex-valued mathematical sequence used in LTE (and similarly in 5G). These sequences have two key properties: (1) Constant Amplitude: Ensures uniform signal strength; and (2) Zero Autocorrelation for Non-Zero Lags. In LTE, the sequence length is 839 (denoted as N_ZC=839) for the standard preamble format. Each cell uses one or more root sequences, identified by a root index (e.g., u). The root sequence is the base Zadoff-Chu sequence. From a single root sequence, multiple preambles can be generated by applying cyclic shifts. A cyclic shift is like sliding the sequence in time by a certain number of steps. The size of the shift, N_CS, is determined by the zeroCorrelationZoneConfig parameter, e.g., from a SIB. It ensures preambles are distinct and detectable. A number of preambles, e.g., 64 preambles, indices are mapped to combinations of root sequences and cyclic shifts. For example, if N_CS allows 10 shifts per root sequence, one root sequence provides 10 preambles. To reach 64, the cell uses multiple root sequences (e.g., 7 roots might cover all 64). The UE calculates which root sequence and shift correspond to its chosen index (e.g., index 42 might be the 2nd shift of the 5th root sequence). Mathematically, for a root Zadoff-Chu sequence X_u(n), the preamble with shift v is: X_u((n+v*N_CS) mod N_ZC) where n=0,1,..., N_ZC-1. V represents the number times a cyclic shift increment (N_CS). In general, v = 0, 1, 2,..., floor(N_ZC, N_CS) - 1.

[0772] Transmitting the preamble: The preamble is transmitted in a Random Access Channel (RACH) opportunity, e.g., a specific time-frequency resource allocated for random access. The raw Zadoff-Chu sequence is not sent alone. It is packaged into a specific format, like LTE's Format 0, which lasts 1 millisecond and includes: (1) A cyclic prefix (to handle timing misalignment); (2) The Zadoff-Chu sequence itself; (3) A guard time (to prevent overlap with other signals). This structure ensures the signal survives real-world issues like multipath fading. Further, The UE calculates the transmission power (power control) based on (1) estimated path loss from downlink signals and (2) Preamble initial received target power indicated by the access device. If the access device does not respond (e.g., due to a collision or weak signal), the wireless device increases the power and retransmits in a later RACH slot, up to a maximum number of attempts. The wireless device modulates the preamble onto the uplink waveform and transmits it in the chosen RACH opportunity. The wireless device listens for these signals, detects the preamble, and responds to proceed with the connection process.

[0773] In a first approach, a wireless device can transmit a second message (e.g., a preamble) in N different slots (e.g., RACH slots) selected at random, and each message indicates which other slots2025P00096EP03

[0774] were used to transmit the message. This approach, optionally combined with a Successive Interference Cancellation (SIC) receiver, increases the chances of successful transmission.

[0775] In a second approach, a wireless device may transmit a second message in N (well-known) slots and / or through B beams to increase the chances of reaching the access device. The access device can use the multiple repetitions of the second message at the well-known slots to improve the reception quality, and thus, increase the coverage.

[0776] It is however challenging to improve both coverage and increase the number of supported wireless devices. This invention aims at tackling this issue.

[0777] The invention proposes the use of a codebook to determine codewords that can facilitate both massive random access and coverage enhancements. Massive random access is facilitated by (1) increasing the chances at least one of the transmissions (of a second message, e.g., preamble) can go through and (2) supporting the usage of several second messages, e.g., one or more preambles and / or a longer preamble. Coverage is enhanced by (3) using codewords that facilitate repetition and / or multiple transmission of second messages, e.g., preambles and / or parts of a long of a preamble. A key feature of the invention is that the codewords that may represent transmission opportunities may share some common transmission opportunities. When codewords selected by wireless devices do not overlap (e.g. because there are only a few wireless devices), the coverage enhancement effect is stronger. When codewords selected by wireless devices do overlap (e.g. because there are many wireless devices), coverage enhancement because the proposed constructions ensure that codewords have at least a minimum of non-overlapping transmission occasions. Finally, the usage of a codebook to identify the codewords facilitates determining which transmission occasions are used by a wireless device, improving massive access.

[0778] In an embodiment of the invention -- allowing a wireless device to perform resilient and massive random access to the network -- that may be combined with other embodiments or used independently, a wireless device may determine a first random-access codebook, wherein the first random-access codebook comprises M codewords of length T, the wireless device may select a first codeword from the first random-access codebook; the wireless device may transmit one or more second messages according to the first codeword.

[0779] In some examples, the wireless device may be a cellular device such as a 5G UE. In some examples, the random-access codebook is a first configuration that determines the codewords that can be used by wireless devices to access the network.

[0780] In some examples, the one or more second messages are copies of each other.In some examples, the one or more second messages have a common part, and an individual part.

[0781] In some examples, the one or more second messages are different preambles selected in a random manner.

[0782] In some examples, the one or more second messages are fragments of a long second message (e.g., fragments of a long preamble).

[0783] In some examples, the one or more second messages are selected in a consecutive manner from the set of available second messages (e.g.., available preambles in a cell).

[0784] In some examples, the selection of the first codeword may be performed by selecting one of the codewords - e.g., of certain parameters in the first random-access codebook at random.

[0785] In some examples, the one or more second messages are simple modifications of the same message, e.g., multiple circular shifts of the same root sequence.

[0786] It is to be noted that the second messages in the previous and other (e.g., below) embodiments are not just be simple repetitions of the same message, while in other embodiments (e.g., above) the second messages are mainly repetitions of the same message.

[0787] In an embodiment of the invention -- allowing a wireless device to perform resilient and massive random access to the network -- that may be combined with other embodiments or used independently,

[0788] - an access device may transmit a first message, e.g., a broadcast message or a unicast message, wherein the first message is adapted to provide one or more wireless devices with a randomaccess configuration, e.g., a codebook configuration and / or a configuration to determine a codeword of a codebook,

[0789] - the access device may receive one or more second messages from at least a first wireless device, and the access device may determine the codeword and / or the one or more second messages transmitted according to the codeword, and

[0790] - the access device may determine transmission resources and / or parameters to transmit a third message, e.g., response message, e.g., a random-access response message based on the determined codebook and / or second messages,

[0791] - and the access device may transmit the third message using the determined transmission resources and / or parameters.

[0792] In an example, the access device may need to perform blind decoding to identify the codewords used during a random-access procedure when receiving the second messages.2025P00096EP03

[0793] In an example, the access device may decode at least a first second message in a transmission occasion, and the first second message may encode the codeword identifier, so that the access device can determine other transmissions occasions used to transmit the remaining of the second messages.

[0794] In a related embodiment of the invention that may be combined with other embodiments or used independently,

[0795] - the first codeword identifies N transmit occasions (e.g., RACH occasions) out of T possible transmit occasions (e.g., RACH occasions) and / or

[0796] - the first codeword has Hamming weight N.

[0797] In a related embodiment of the invention that may be combined with other embodiments or used independently, the Hamming distance between any two distinct codewords in the first random-access codebook is at least K.

[0798] In some examples, two sequences of transmit occasions from the first random-access codebook may have at least K non-overlapping transmit occasions.

[0799] In an example, the two or more sequences may form a Latin Rectangle. A Latin rectangle is a combinatorial structure that generalizes the concept of a Latin square. A Latin square is an T x T array filled with T different symbols, each occurring exactly once in each row and exactly once in each column. A Latin rectangle, on the other hand, is an M x T array (where M < T), filled with T different symbols such that each symbol appears at most once in each row and at most once in each column. The structure of Latin rectangles makes them a valuable tool in various fields such as design theory, error-correcting codes, and scheduling problems. The primary characteristic that differentiates a Latin rectangle from a Latin square is its rectangular shape and the constraint that each symbol does not necessarily need to appear in every row and column— only at most once per row and column. Constructing a Latin rectangle involves arranging symbols in such a way that the constraints are satisfied. For example, consider a 3 x 5 Latin rectangle filled with the symbols 1, 2, 3, 4, and 5. An arrangement could look like this:

[0800] 12345

[0801] 2345 1

[0802] 345 12

[0803] In the above concrete example, each column may correspond to a codeword, and the entries may indicate which of the 5 transmission occasions is used when the codeword is selected. Forinstance, the first column contains (1,2,3) indicating that the first three transmission occasions are used.

[0804] In an example, the first random-access codebook is a binary constant weight code with word length T, code weight N and minimum Hamming distance K.

[0805] For example, a codebook with M codewords may be represented as a TxM matrix C with 0,1 entries, where a device employing codeword j uses as transmit opportunities the indices i for which C(i,j)=1. For example, we can choose the 7x5 matrix with columns (100011)AT, (010101)AT,(001110)AT, (111000)AT, (100100)AT, whereAT denotes "taking the transpose" So there are T=7 transmit opportunities; the codebook has 5 words. The leftmost four codewords correspond to using three transmit opportunities; the rightmost codeword corresponds to using two transmit opportunities. No column has all its ones in the positions of the ones of another vector. As a result, if two devices use the transmit opportunities for transmitting their messages, no message collision occurs, provided that the two devices selected different codewords.

[0806] In an example, any M distinct code words form an TxM matrix comprising an MxM submatrix in which each row and each column contains exactly one '1'. This guarantees that all messages get through if at most m devices are active and each of them selects and / or is assigned a different entry. An example is a binary constant weight code with code word weight N and minimum Hamming distance equal to 2N-2, so that any two codewords share at most one common transmit opportunity. For example, the weight N=3 codewords of a Hamming code of length 15 (which by definition has minimum Hamming distance K=3) form a codebook of 35 codewords with the property that for any three devices selecting distinct codewords, each device has a transmit opportunity in which it is the only transmitting device. More generally, the Hamming code of length T(T-l) / 6 has words of weight three and thus gives rise to a codebook with T(T-l) / 6 words, any three distinct codewords allow retrieval of three transmitted messages.

[0807] In an embodiment with K=2, thew codewords are linear combinations, using the bitwise exclusive-OR as addition, of one or more basis words. There are T-l basis words, where each basis word is a binary vector of length T, where T > 2. The basis vectors are labeled 0 through T-2, and the positions within a vector are labeled 0 through T-l, and P (for parity). The basis vector with label k has a one in the position labeled k and in the position P, and zeros in the T-2 other positions. The codeword that is the addition of the basis words with labels kl...kn is assigned the codeword label 2kl+...+2kn. For example, when T=4 the basis words are given in the following table. For example, when T=4 the basis words are given in the following table.

[0808] Label position \

[0809] 0 1 2 P

[0810]

[0811] basis word2025P00096EP03

[0812] 0 1 0 0 1

[0813] 1 0 1 0 1

[0814]

[0815] 2 0 0 1 1

[0816] The codewords, with their respective codeword labels are then as follows:

[0817] 1 1001

[0818] 2 0101

[0819] 3 1100

[0820] 4 0011

[0821] 5 1010

[0822] 6 0110

[0823] 7 1111

[0824]

[0825] Codewords 1 through 6 have Hamming weight N=2, codeword 7 has Hamming weight 4. The function to generate the codeword for this particular codebook is F(i, N, T=4) = (bO, bl, b2, b3) where i = bO + 2*bl + 4*b2 and b3 = bO + bl+ b2 mod 2, 1 <= i <=7 and N=4 if i=7 and N=2 otherwise.

[0826] In an exemplary embodiment with K=3, the codewords are linear combinations of one or more basis words. Linear combinations may be done using the bitwise exclusive-or (XOR) as addition. In an example, a basis word with label k comprises two parts: one part consists of all zero bits, except for a one bit in the position with position label k, the other part consists of bits that form a binary representation of the number k. The codeword that is the addition of the basis words with labels kl...kn is assigned the codeword label 2kAl+...+2kn. The basis word labels are chosen such that the binary representation of each basis word label k has at least 2 ones, so that the Hamming weight of the corresponding basis word is at least 3. This implies that the minimum distance of the resulting codebook is at least K. The Hamming weight N of the codeword with label c is equal to the number of ones in the binary representation of c plus the number of ones in the result of the addition of parity bits of the basis words that comprise the codeword. The codebook consists of the codewords with one or more prescribed values of N. Choosing a subset of all possible codewords may increase the minimum distance to a value greater than 3. For example, this construction can be used to generate a codebook in which all codewords have Hamming weight N=5 and the minimum distance K=4. Let the basis word labels be 4-bit numbers. The 11 basis word labels are 3, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15 and the basis words are given in the following table, where the top rows contain the position and parity labels and their reduced values, and the leftmost column contains the basis word labels and its reduced values. Basis word labels 0, 1, 2, 4, and 8 do not occur, because the number of ones in their binary representations is less than 2. The codeword with label 1096 = 2A3 + 2A6+2A10 is then10100100001111 and has Hamming weight N=7. We can define the reduced base word and position words by enumerating the occurring base word labels: 3 --> 0, 5 --> 1, 6 --> 2, 7 --> 3, 9 --> 4, 10 --> 5, 11 --> 6, 12 --> 7, 13 --> 8, 14 --> 9,15 --> 10, and the corresponding code word label by replacing the base word labels in the exponents by the reduced base word labels. The codeword with label 1096 then gets reduced codeword label 2A0 + 2A2 + 2A5 = 37. The number of codewords that can be obtained by means of this approach equals two to the power of the number of labels or the number of reduced labels. In this case, there are 11 reduced labels, and thus, the total number of codewords is 2048.

[0827] Reduced

[0828] Label 0 1 2 3 4 5 6 7 8 9 10 ParO Pari Par2 Par3 Reduced

[0829] Label

[0830] Label 3 5 6 7 9 10 11 12 13 14 15 ParO Pari Par2 Par3 0 3 1 0 0 0 0 0 0 0 0 0 0 1 1 0 0 1 5 0 1 0 0 0 0 0 0 0 0 0 1 0 1 0 2 6 0 0 1 0 0 0 0 0 0 0 0 0 1 1 0 3 7 0 0 0 1 0 0 0 0 0 0 0 1 1 1 0 4 9 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 5 10 0 0 0 0 0 1 0 0 0 0 0 0 1 0 1 6 11 0 0 0 0 0 0 1 0 0 0 0 1 1 0 1 7 12 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 8 13 0 0 0 0 0 0 0 0 1 0 0 1 0 1 1 9 14 0 0 0 0 0 0 0 0 0 1 0 0 1 1 1

[0831]

[0832] 10 15 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 In this example, the codebook may also be chosen as the set of all codewords with Hamming weight N=5. This gives the following codebook with 168 codewords, together with their reduced labels:

[0833] Red. Red. Red. Red.

[0834] codeword codeword codeword codeword Label Label Label. Label 10101000000001 01101000000010 00011000000011 11011000000000 21 22 24 27

[0835] 1 1 1 1 11000100000001 01100100000100 00010100000101 10110100000000 35 38 40 45

[0836] 1 1 1 1 01001100000011 00101100000101 01011100000100 00111100000010 50 52 58 60

[0837] 0 0 0 0 01000010000011 00100010000101 01010010000100 00110010000010 66 68 74 76

[0838] 1 1 1 1 11001010000001 01101010000100 00011010000101 10111010000000 83 86 88 93

[0839] 0 0 0 0 10100110000001 01100110000010 00010110000011 11010110000000 101 102 104 107

[0840] 0 0 0 0 11000001000010 10100001000100 00010001000110 01110001000000 131 133 136 142

[0841] 1 1 1 1 10001001000011 00101001000110 10011001000100 00111001000001 145 148 153 156

[0842] 0 0 0 0 10000101000101 01000101000110 10010101000010 01010101000001 161 162 169 170

[0843]

[0844] 0 0 0 000011101000000 00000011000111 11000011000100 10100011000010 184 192 195 197

[0845] 1 0 0 0 01100011000001 00101011000000 01000111000000 00001111000001 198 212 226 240

[0846] 0 1 1 0 10000000100011 00100000100110 10010000100100 00110000100001 257 260 265 268

[0847] 1 1 1 1 11001000100010 10101000100100 00011000100110 01111000100000 275 277 280 286

[0848] 0 0 0 0 00000100100111 11000100100100 10100100100010 01100100100001 288 291 293 294

[0849] 0 0 0 0 00101100100000 10000010100101 01000010100110 10010010100010 308 321 322 329

[0850] 1 0 0 0 01010010100001 00011010100000 00000110100001 01001110100000 330 344 352 370

[0851] 0 1 1 0 10100001100001 01100001100010 00010001100011 11010001100000 389 390 392 395

[0852] 0 0 0 0 10000101100000 00001101100010 00000011100010 10001011100000 417 432 448 465

[0853] 1 0 1 0 10000000010101 01000000010110 10010000010010 01010000010001 513 514 521 522

[0854] 1 1 1 1 00001000010111 11001000010100 10101000010010 01101000010001 528 531 533 534

[0855] 0 0 0 0 11000100010010 10100100010100 00010100010110 01110100010000 547 549 552 558

[0856] 0 0 0 0 01001100010000 10000010010011 00100010010110 10010010010100 562 577 580 585

[0857] 1 0 0 0 00110010010001 00001010010001 00010110010000 00101110010000 588 592 616 628

[0858] 0 1 1 0 11000001010001 01100001010100 00010001010101 10110001010000 643 646 648 653

[0859] 0 0 0 0 10001001010000 00001101010100 00000011010100 10000111010000 657 688 704 737

[0860] 1 0 1 0 01000000110011 00100000110101 01010000110100 00110000110010 770 772 778 780

[0861] 0 0 0 0 00001000110010 00000100110100 00001010110100 00000110110010 784 800 848 864

[0862] 1 1 0 0 00010001110000 00101001110000 01000101110000 00000011110001 904 916 930 960

[0863] 1 0 0 0 00000000001111 11000000001100 10100000001010 01100000001001 1024 1027 1029 1030

[0864] 1 1 1 1 10001000001101 01001000001110 10011000001010 01011000001001 1041 1042 1049 1050

[0865] 0 0 0 0 10000100001011 00100100001110 10010100001100 00110100001001 1057 1060 1065 1068

[0866] 0 0 0 0 00001100001001 11000010001010 10100010001100 00010010001110 1072 1091 1093 1096

[0867] 1 0 0 0 01110010001000 01001010001000 00100110001000 00011110001000 1102 1106 1124 1144

[0868] 0 1 1 0 01000001001011 00100001001101 01010001001100 00110001001010 1154 1156 1162 1164

[0869] 0 0 0 0 00001001001010 00000101001100 00001011001100 00000111001010 1168 1184 1232 1248

[0870] 1 1 0 0 11000000101001 01100000101100 00010000101101 10110000101000 1283 1286 1288 1293

[0871] 0 0 0 0 10001000101000 00001100101100 00000010101100 10000110101000 1297 1328 1344 1377

[0872] 1 0 1 0 00100001101000 00011001101000 00000101101001 01000011101000 1412 1432 1440 1474

[0873] 1 0 0 0 10100000011001 01100000011010 00010000011011 11010000011000 1541 1542 1544 1547

[0874] 0 0 0 0 10000100011000 00001100011010 00000010011010 10001010011000 1569 1584 1600 1617

[0875]

[0876] 1 0 1 001000001011000 00001001011001 00010101011000 00100011011000 1666 1680 1704 1732

[0877] 1 0 0 0 00000000111001 01001000111000 00100100111000 00010010111000 1792 1810 1828 1864

[0878]

[0879] 1 0 0 0

[0880] It turns out that the minimal distance for this codebook is K=4: since in this example all codewords have the same weight, the minimum distance must be even, so it cannot be 3.

[0881] In an embodiment, a codeword is computed given an index i, a codeword Hamming weight N and a codeword length T = 2Ap - 1 where p is at least 3, using the function F given by

[0882] F(i, N, T=2Ap-l) = (X(N, p, i) * A(N, p)) mod 2

[0883] where

[0884] A(N, p) is a matrix of size (2Ap-p-l) x (2Ap-1),

[0885] the k-th row of A(N, p) has zeros in the first 2Ap - p - 1 positions, except for a 1 in position k,

[0886] the bits in positions 2Ap - p,...2Ap - 1 satisfy s(k, p) = sum( 2A(j-l) A(N, T)_{k, T - p + j }, j=l,...p), for each k=l,...,2Ap-p-l,

[0887] X(N, p, i) is the binary row vector (xl, x2,...) of length 2Ap-p-l with

[0888] sum(2A{j-l) xj, j =1,..., 2Ap-p-l) = r(N, p, i)

[0889] and [r( N,p, 1), r(N,p,2),...,r(N, p, S(N, p))] is an array of integers z for which (Z(z) * A(N, p)) mod 2 has Hamming weight N, where Z(z) is the binary row vector of length 2Ap-p-l such that z = sum(2A{j-l} Z(z)_j, j= 1,..,2Ap-p- 1 ).

[0890] In a related embodiment of the invention that may be combined with other embodiments or used independently, only a subset of the codewords (that can be generated by means of a function, e.g., F(i)) may be selected. For instance, codewords may be selected based on the Hamming weight (e.g., value N) so that only low weight codewords are selected. The available codewords may be indicated to the wireless devices by the access device so that the access device only needs to monitor the indicated subset.

[0891] In an embodiment with minimum distance at least K+l, the basis codewords are constructed from a codebook with minimum distance K, comprising S codewords of length T. The S basis codewords have length S+T. The matrix of basis codewords is the horizontal concatenation of the SxS identity matrix and the SxT codebook matrix. In an example: take the codebook with K=4 and2025P00096EP03

[0892] N=5 from the previous example. This first codebook has S=168 codewords of length T=15. This construction gives a new codebook with up to 2168-1 non-zero codewords. The minimum distance of the new codebook is 6, since each basis vector has Hamming weight 5 + 1 = 6, at least 2 basis vectors must be added to get 4 non-zero parity bits since the minimum distance of the first codebook is 4, and if it is possible to make a linear combination that gives 3 non-zero parity bits it must consist of at least 3 basis vectors. No combination of the basis vectors has less than 3 non-zero parity bits, since the first codebook is a subset of a complete (except for the all-zero codeword) linear codebook with minimum distance 3.

[0893] In a related embodiment of the invention that may be combined with other embodiments or used independently, the wireless device may receive an indication of N and / or T and / or K from a first access device; and the wireless device may use the indication to determine the first random-access codebook and / or the first codeword.

[0894] In an example, an access device may indicate the parameters in a SIB.

[0895] In an example, an access device may provide the wireless device with the parameters in an RRC message.

[0896] In an example, the wireless device may select codewords of increasing length (T), Hamming weight (N), and Hamming distance (K) for enhanced coverage and / or enhance massive access, wherein the parameters to select may be indicated by the access device, and may be adapted depending on, e.g., the number of retransmissions.

[0897] In a related embodiment of the invention that may be combined with other embodiments or used independently, the wireless device may receive a first signal (e.g., a system information block and / or synchronization signals and / or a reference signal and / or an RRC message) from a second access device,

[0898] the wireless device may determine one or more features of the first signal, and and the wireless device may determine the first random-access codebook and / or the first codeword based on the one or more features of the first signal.

[0899] In an example, the one or more features determined from the first signal may comprise at least one of:

[0900] - the signal strength of the first signal;

[0901] - the signal quality of the first signal;

[0902] - the type of second access device;

[0903] - the number of wireless devices attempting to perform random-access;In an example, a higher N value may be selected when the signal strength is below a first threshold, and / or the signal quality is below a second threshold, and / or the distance to the second access device is higher than a third threshold.

[0904] In an embodiment of the invention that may be combined with other embodiments or used independently, the number of repetitions / transmission of second messages (i.e., N value) may be determined by the UE by comparing the measured received signal strength (e.g., RSRP) of one or more reference signals and / or synchronization signals and / or beams of these signals from the access device with a threshold configured on the UE by either common RRC signalling (e.g., a SIB message) or dedicated RRC signalling (e.g., RRC reconfigurationWithSync).

[0905] In an embodiment of the invention that may be combined with other embodiments or used independently, the UE may determine the number of different beams to be used for transmission of second messages, e.g., repetitive preamble transmissions and / or the number of repetitive preambles in each beam by comparing the parameters, e.g., measured received signal strength of one or more reference signals and / or synchronization signals and / or beams of these signals from the access device with a threshold configured on the UE by either common RRC signalling (e.g., a SIB message) or dedicated RRC signalling (e.g., RRC reconfigurationWithSync).

[0906] In an embodiment of the invention that may be combined with other embodiments or used independently, the access device may associate / configure a received signal strength (e.g., RSRP) for UE to determine the number of beams to use and the number of repetitions in each beam. The UE may measure the RSRP of one or more beams from the access device and may apply a function (e.g., average, minimum, maximum) to the measurement values to determine which beam directions to use in beam sweeping and how many repetitions may be used in each beam direction.

[0907] In an embodiment of the invention that may be combined with other embodiments or used independently, each beam direction of the reference signals and / or synchronization signals from the access device may be associated / configured with a list of received signal strength (e.g., RSRP) thresholds to be used by the UE to determine the number of repetitions to be used for the RACH preamble repetitive transmissions in different beams.

[0908] In an example, a higher K value may be selected when the signal strength is below a fourth threshold, and / or the signal quality is below a fifth threshold, and / or the distance to the second access device is higher than a sixth threshold; and / or

[0909] In an example, when N increases, a higher value of T may also be required.

[0910] In an example, when K increases, a higher value of N may be required.

[0911] In a related embodiment of the invention that may be combined with other embodiments or used independently, the first random-access codebook may be received from a third2025P00096EP03

[0912] access device and / or a core network function. For instance, it may be configured depending on the location of the wireless device, the type of access required (e.g., terrestrial vs non-terrestrial).

[0913] In some examples, the first random-access codebook may be determined from a preconfigured list or set of codebooks and the determined first random-access codebook is identified by means of a codebook index. For instance, a set of codebooks may be configured, each codebook of different properties, e.g., depending on the number of devices that are seeking access (since this influences T, N, K), the coverage requirements since this influences (K). Depending on the measurements performed by the wireless device, the type of service required by the wireless device, and / or the indications received by the wireless device, the wireless device will select / determine one of the codebooks as the first random-access codebook, and determine from it its first codeword. In some examples, a wireless device may not succeed in a first random access procedure and may adapt the parameters by selecting a different codebook.

[0914] In a related embodiment of the invention that may be combined with other embodiments or used independently, the T transmission occasions may be one of or a combination of:

[0915] - distinct time slots;

[0916] - distinct non-overlapping frequency sub-bands;

[0917] - distinct non-overlapping frequency sub-bands in a single equal timeslot, since it enables 'quick' recovery, maybe less energy usage because of not switching on and off;

[0918] - distinct non-overlapping blocks in the time-frequency plane;

[0919] - distinct transmit occasions in different beams;

[0920] - distinct transmit occasions associated to different geographical locations.

[0921] It is to be noted that a transmit occasion can also be considered / named in a different manner, e.g., communication resources, as used in embodiments of the invention.

[0922] In a related embodiment of the invention that may be combined with other embodiments or used independently, some (e.g., N) of the T transmission occasions may be selected by the wireless device means of the first codeword. The selected transmission occasions may be mapped to one or more of timeslots, frequency sub-bands, beams, geographical locations. Mapping can be done by means of function G that takes as input available resources (time, frequency, beams) and codeword, and outputs which transmission occasions are allocated in which available communication resources.In an embodiment of the invention that may be combined with other embodiments or used independently, the codebook may be encoded by indicating the non-zero positions of the codewords. For instance, the 16 bit long binary codeword 1000000100000000, where the left bit is the least significant bit may be encoded as [0,7]. This encoding requires only 8 bits.

[0923] In an embodiment of the invention that may be combined with other embodiments or used independently, M distinct codewords form an TxM matrix comprising an MxM submatrix in which each row and each column contains exactly one '1'.

[0924] In an embodiment of the invention that may be combined with other embodiments or used independently, a first random-access codebook may comprise codewords of a first length N and a second length N2. In general, it may comprise codewords of multiple lengths, e.g., lengths between N_min and N_max. A wireless device may select codewords of a given length, e.g., increasing or decreasing length, depending on the communication needs.

[0925] In some examples, a first random-access codebook comprises codewords of a first length N and a second random-access codebook comprises codewords of a second length N2. In general, there may be codebooks of multiple lengths depending on the communication needs.

[0926] In some examples, the codeword selection length and / or the codebook selection may depend on a determined required codeword Hamming weight.

[0927] Similarly, the codewords in a codebook may have different K, T parameters.

[0928] Similarly, there may be codebooks of featured by different K, T parameters.

[0929] In an embodiment of the invention that may be combined with other embodiments or used independently, the determined first random-access codebook and / or the selected first codeword depend on one or more of:

[0930] the device capabilities of the wireless device. For instance, devices with lower transmission power may select codewords with a higher N / K value. For instance, devices with higher transmission power may select codewords with a lower N value;

[0931] the detection of a second wireless device by the wireless device and / or of a transmission by the second wireless device when transmitting the second message. When a wireless device determines the transmission of the second wireless device, the wireless device may determine which potential codewords the second wireless device may be using (since it has already determined one transmission). Th is may a How the wireless device to check whether it is the same codeword and / or there is a better related choice.In an embodiment of the invention that may be combined with other embodiments or used independently, the wireless device may receive a first signal from a fourth access device, wherein the first signal (e.g., SIB, RRC message) indicates a transmission chance. The wireless device may transmit the second message according to the first codeword and to this end, the wireless device may determine whether the wireless device can perform the transmission in a first set of communication resources or a second set of communication resources based on the indicated transmission chance.

[0932] For instance, if the number of devices attempting to gain access is low, the access device may distribute a transmission chance of 1. Any wireless device may then perform random access.

[0933] For instance, if the number of devices attempting to gain access is high, the access device may distribute a transmission chance of 0.1. A wireless device may then perform random access in a current random-access procedure if it selects a random number between 0 and 1, and the random number is between 0 and 0.1. Otherwise, it may need to wait for the next random-access procedure.

[0934] For instance, certain parameters of the selected codebook and / or codeword may also depend on the transmission chance. For instance, in the previous chance, if the selected random number is between 0 and 0.1, the wireless device may select more "powerful" codewords, e.g., higher T value or higher N value. In contrast, another wireless device selecting a random number between 0.1 and 1 may need to use less powerful codewords, e.g., with a lower N value.

[0935] In an embodiment of the invention that may be combined with other embodiments or used independently, the wireless device may receive a second message (e.g., a random-access response message) from an access device. The communication resources (e.g., time / frequency) and / or parameters (e.g., radio network temporal identifier) used to transmit / encode / decode the second message may be determined - totally or partially -- by one or more of:

[0936] - the first codeword, e.g., the bit sequence indicated by the first codeword. In this case, the access device may need to determine, e.g., each of the transmission occasions used by the wireless device, and derive from it, e.g., the codeword, and use it to, e.g., determine resources / para meter;

[0937] - the codebook entry of the selected first codeword, for instance, the access device may need to determine the codebook entry (e.g., by checking it in one of the second messages transmitted in one of the transmission occasions) and verifying that the same (or related) first message appears in other related transmission occasions belonging to the same codeword. If this is confirmed, the codebook entry may then be used to determine transmission resources / parameters for the second message;2025P00096EP03

[0938] - any transmission occasion indicated by the first codeword: in some cases, the access device may not be able to decode all second messages transmitted in all transmission occasions of the codeword. Thus, the access device may select transmission resources / parameters for the second message that depend on one (or several) of the transmission occasions.

[0939] It is noted that in legacy procedures, RACH occasion used for transmitting the initial preamble has one-to-one mapping relationship between RACH Occasion and RAR response. However, when multiple second messages (e.g., preambles) are transmitted, e.g., according to the first codeword, and this may imply through different beams, the resources / parameters used for the transmission of the response message may be selected differently. This is also the case when multiple preambles through different beams are transmitted for coverage enhancements. For instance, the resources / parameters used for the transmission of RAR messages may depend on the first messages / preambles transmitted through, e.g., two beams. The UE may need to monitor multiple resources when waiting to receive the RAR. Depending on which resources are used to transmit the one or more RARs, the UE could also determine how the access device received the preambles.

[0940] In an embodiment of the invention that may be combined with other embodiments or used independently, a Radio Network Temporal Identifier, RNTI, e.g., RA-RNTI used to scramble RAR message from the access device in response to reception of one or more second messages (e.g., preambles) may be determined from the time and / or frequency location of the one or more RACH Occasions, e.g., the last RACH Occasion (RO) in a group of ROsIn each RO of the group of ROs UE may repeatthe second messages (e.g., preambles) one or more times in the same beam and / or in different beams according to the number of repetitions determined by the configuration and / or some measurement in the wireless device of some reference signals, synchronization signals. The access device may use the above RNTI (e.g., RA-RNTI) to scramble the RAR message for a wireless device, and the wireless device may use the above RNTI (e.g., RA-RNTI) to decode the RAR message from the access device.

[0941] In an embodiment of the invention that may be combined with other embodiments or used independently, the transmit occasions may be partitioned into two or more (up to S) disjoint subsets A_l, A_2,..., A_S and codewords may be pairs (a_l, a_2,...,a_S) with a_i in A_i.

[0942] In an example, the set of transmit opportunities is partitioned into two disjoint subsets A and B, and codewords are pairs (a,b) with a in A and b in B. For example, A and B may correspond to even and odd-indexed transmit opportunities, respectively. Assume that three distinct codewords (a i,bi) are chosen, and message mi is transmitted in opportunity ai and bi. If all ai are different, then each mi can be retrieved. If all ai are equal, then all bi are different, and each message can be retrieved.The essentially only problematic case is al=a2^a3 and bl=b3^b2. Then m3 can be retrieved from transmit opportunity a3, and m2 can be retrieved from transmit opportunity b2. The knowledge of m2 (m3) from transmit opportunity b2 (a3) can be used to retrieve ml from transmit opportunity al(bl). So with an interference cancellation technique, all three messages can be retrieved. For example, if T=15, and A and B correspond to the even and odd indices, then the codebook has 8x7=56 words, compared to the 35 words of weight 3 in the Hamming code of length 15. In this example, in b...

Claims

Claims1. A method performed by a first wireless device for enhancing coverage, comprising: - receiving a first message and / or determining, by the first wireless device, a first configuration for accessing a first access device and / or a second access device,- transmitting, by the first wireless device, to the first access deviceN second messages with N being at least 1,through M beams with M being at least 1, andwherein selection of N and M is according to the first configuration.

2. A method for enhancing coverage, comprising:- receiving a first message and / or determining, by a first wireless device, a first configuration for accessing a first access device and / or a second access device,- transmitting, by the first wireless device, to the first access device and the second access device,N second messages with N being at least 1,through M beams with M being at least 1, andwherein the selection of N and M is according to the first configuration.

3. The method of any previous claims, further comprising:- performing, by the first wireless device, a data exchange with or through the first access device and / or a second access device.

4. The method of any previous claims, further comprising:- connecting, by the first wireless device, to the first access device or second access device upon transmitting at least one of the N second messages.

5. The method of any previous claims, wherein a pathloss between the first wireless device and the first access device is lower than a pathloss between the first wireless device and the second access device.

6. The method of any previous claims, wherein the first message is one of:- an RRC message, and- a SIB1 message,- a SIB message,2025P00096EP03- a pre-configuration in the first wireless device,received from the first access device and / or the second access device and / or a third access device.

7. The method of any previous claims, further comprising:- receiving, by the first wireless device, one or more reference signals, - measuring, by the first wireless device, one or more parameters of the reference signals, and- determining, by the first wireless device, N based on the one or more measured parameters and the first configuration.

8. The method of any previous claims, further comprising:- receiving, by the first wireless device, one or more reference signals, - measuring, by the first wireless device, one or more parameters of the reference signals,- determining, by the first wireless device, M based on the one or more measured parameters and the first configuration.

9. The method of claims 7 or 8, wherein the one or more parameters of the reference signals comprise one or more of:- signal strength of each reference signal,- signal quality of each reference signal,- measured frequency shift of each reference signal,- angle of arrival of the reference signal.

10. The method of Claim 9, wherein the first wireless device determines the number of beams M used to perform the transmission of N second messages, based on one or more of:- the minimum M_min number of beams required,- the maximum M_max number of beams supported by the first wireless device, - a first threshold value for selecting M, wherein if the received signal strength of the reference signal is less than the first threshold, M > M_min;- a second threshold value for selecting the beams, wherein a beam is eligible if the received signal strength of the beam is greater than the second threshold.

11. The method of any previous claims, wherein the time between second messages is determined based on the first configuration.

12. The method of any previous claims, further comprisingtransmitting, by the first wireless device, second messages through M different beams according to a beam transmission mode and the beam transmission mode is one of:- simultaneously,- sequentially,- alternatingly,- increasingly.

13. The method of any of the previous claims, wherein the first configuration comprises an indication of allowed configurations, wherein an allowed configuration indicates one or more of:- number of second message transmission per beam;- total number of second message transmission;- total number of beams;- order in which the second messages are transmitted via different beams;- time / frequency resources used for a group of second messages transmitted via different beams.

14. The method of any of the previous claims,wherein the first configuration comprises a first set of communication resources allocated to transmit one or more second messages through a single beam ( M=l) and a second set of communication resources allocated to transmit one or more second messages through two or more beams (M>1), andwherein transmitting, by the first wireless device, N second messages comprises: - transmitting N second messages in the first set of resources when a single beam is used, or- transmitting N second messages in the second set of resources when two or more beams are used.

15. The method of any of the previous claims,wherein the first configuration comprises a first set of second messages allocated to transmit one or more second messages through a single beam (M=l) and a second set of second messages allocated to transmit one or more second messages through two or more beams ( M > 1 ), and wherein transmitting, by the first wireless device, N second messages comprises: -transmitting N second messages selected from the first set of second messages when a single beam is used, or- transmitting N second messages selected from the second set of second messages when two or more beams are used, wherein the N second messages are:- a shifted version of each other;- identical;- an ordered subset of the second messages in the second set of second messages.

16. The method of any previous claims, wherein the second messages are transmitted through at least two beams, wherein a first beam is a beam wider than the second beam, and wherein at least a second message transmitted through the first beam is transmitted before the first second message transmitted through the second beam.

17. The method of any previous claims, wherein at least one of the N second messages encodes the values N and / or M.

18. The method of any previous claims, wherein the second message transmitted in k position encodes the value k, or wherein each second message encodes distinct sequence numbers, wherein a second message with a lower sequence number is transmitted at the same or at an earlier time than a second message with a higher sequence number.

19. The method of any previous claims, wherein a current second message encodes a beam identifier used to transmit a subsequent second message.

20. The method of any previous claims, wherein a current second message encodes parameters used to transmit a subsequent second message.

21. The method of any previous claims, wherein the N second messages encode one or more identifiers, and the one or more identifiers are associated to the N second messages.

22. The method of any previous claims, further comprising:- after transmitting at least one of the N second messages, receiving, by the first wireless device, L third messages with L equal or greater than 1.

23. The method of claim 22, further comprisingreceiving the L third messages according to one or more of:at least one third message after the transmission of each second message;up to L third messages after the transmission of all N second messages.

24. The method of claim 22 or 23, further comprising:performing, by the first wireless device, the data exchange with or through the first access device and / or second access device as a result of receiving at least 0 third messages, with 0 equal or greater than 1.

25. The method of any of claims 22, 23 and 24, further comprising at least one of: - stopping transmitting, by the first wireless device, any further second messages as a result of receiving at least one third message;- stopping transmitting, by the first wireless device, any further second messages through a second beam as a result of receiving at least one third message through a first beam.

26. The method of any of claims 22 to 25, further comprising:- determining, by the first wireless device, the reception of less than 0 third messages; - determining, by the first wireless device, a new set of configuration parameters for the transmission of a subsequent set of second messages.

27. The method of any previous claims, wherein the second message is one of: - a preamble to perform a random-access procedure,- a wake-up signal,- an uplink wake-up signal,- a message to complete the setup of a radio resource control protocol.

28. The method of any previous claims, wherein the third message is a random access response message.

29. The method of any previous claims 21-28, comprising- determining, by the first wireless device, a preferred beam based on one or more of: an indication on at least one third message, and / ormeasurements of the third messages, and / orthe reception of one or more third messages through a beam.

30. The method of any previous claims, wherein the first configuration comprises one or more of:- transmission power of the reference signals,- a load indication of the first access device,- a load indication of the second access device,- an indication of the maximum N, M, L, and 0 values allowed and / or used by the first access device and / or second access device,- beam transmission mode,- timing between transmission of second messages,- one or more functions determining the N value based on the one or more measured parameters,- one or more functions determining the M value based on the one or more measured parameters,- transmission parameters as a function of N and / or M, wherein the transmission parameters may comprise one or more of transmission power, timing, encoding, and modulation of one or more of the N second messages,- the identity of the first access device and / or the second access device, - an AI / ML model allowing determining one or more parameters for the transmission of the second messages;- monitoring / transmission mode;- communication parameters of, e.g., second messages, such as time location, frequency location, pre-coding matrix of the spatial stream;- minimum / maximum M value;- determining the change of M based on the number failed random access procedures; - whether beams of one or more than one access devices can be used; -whether / how many multiple access device beams and / or wireless device beams are selectable.

31. The method of any of Claims 2 and 30, whereinthe first configuration comprises one or more parameters common to the first access device and the second access device.

32. The method of any previous claims, wherein at least a first beam in the M beams is selected based on a predicted beam measurement.

33. The method of any previous claims, wherein:- one or more second messages are transmitted through a first beam, and- the data exchange with or through the first access device and / or a second access device is performed through a second beam, and:- one or more of the second messages indicate the second beam.

34. The method of any previous claims 31 to 33, further comprising: transmitting, by the first access device, one or more of:reference signals,a SIB message containing a first configuration,an RRC message containing a first configuration,an RRC Registration Request,an RRC Connection Complete,an RRC Connection Reconfiguration Complete,35. The method of any previous claims, further comprising:determining, by the first access device, a preferred beam for communication with the first wireless device based on the one or more received second messages.

36. A method performed by a wireless device for low PAPR communication comprising:receiving via a first signaling and / or obtaining, by the wireless device, a modulation and coding, (MAC, indication whether (1) modulation information and coding information for one or more modulation and coding scheme, MCS, indices are coupled or decoupled; and / or (2) modulation information for one or more MCS indices, andreceiving, by the wireless device, via a third signaling, an assignment of a modulation and coding scheme for a subsequent transmission.

37. The method of claim 36, wherein prior to the reception of the third signaling, transmitting, by the wireless device, a second signaling indicating if the wireless device supports for pi / 2-BPSK for one or more modulation and coding scheme indices.

38. The method of claims 36 or 37,- wherein the first signaling is transmitted via a SIB1 or RRC message; and / or - wherein the MAC configuration indicates a maximum MCS index up to which n / 2-BPSK is applicable; and / or- wherein modulation information for one or more modulation and coding scheme (MCS) indices is 1 bit long, and indicates for two or more MCS entries whether a high PAPR modulation or a low PAPR modulation is used, and / or- wherein modulation information for two or more modulation and coding scheme (MCS) indices is 1 bit long, and indicates whether a high PAPR modulation or a low PAPR modulation is used for each and every MCS entries for which two modulation schemes are applicable, and / or - wherein modulation information for two or more modulation and coding scheme (MCS) indices is 1 bit long, and indicates whether a high PAPR modulation or a low PAPR modulation is used for each and every MCS entries for which two modulation schemes are applicable, wherein the two or more MCS indices jointly have three or more modulation orders, and / or- wherein the MAC configuration indicates the modulation order to be used with one or more MCS indices of an MCS table; and / or- wherein the MAC configuration configures whether modulation order (e.g., n / 2-BPSK) selection is performed by the wireless device, the access device, or both; and / or- wherein the MAC configuration configures whether n / 2-BPSK is applied to uplink and / or downlink transmissions; and / or- wherein the MAC configuration configures one or more fixed spectral-efficiency thresholds used to determine the applicability of one or more modulation orders (e.g., n / 2-BPSK, QPSK, etc) for the assigned MCS index; and / or- wherein the MAC configuration configures a table comprising multiple available modulation-coding pairs per MCS index, including at least one pair corresponding to n / 2-BPSK; and / or wherein the MAC configuration configures a decoupled MCS mode in which a modulation-order indicator is provided independently of a coding-rate and / or code scheme indicator; and / or2025P00096EP03- wherein the wireless device stores the MAC configuration in first signaling in a configuration memory and applies the MAC configuration for subsequent uplink transmissions without further first signaling; and / or- wherein the second signaling comprises a bitmap indicating a modulation order (e.g., n / 2-BPSK) support for a plurality of MCS indices; and / or- wherein the second signaling comprises an indication indicating a modulation order (e.g., n / 2-BPSK) support for a plurality of MCS indices (e.g., up to a given MCS index); and / or- wherein the second signaling identifies a set of MCS indices for which the wireless device supports both two or more modulations (e.g., n / 2-BPSK and QPSK), enabling dual-mode operation.- wherein the second signaling indicates whether the wireless device supports n / 2-BPSK operation for one or more communication procedures (e.g., HARQ retransmissions, downlink transmission); and / or- wherein the third signaling comprises an indicator identifying whether modulation order and coding rate / scheme are selected jointly or independently; and / or- wherein the third signaling comprises a bitstring identifying one of a plurality of modulation-coding pairs associated with the assigned MCS index; and / or- wherein the third signaling comprises a parameter indicating whether mirrored n / 2-BPSK coefficients are kept, removed, or added for the uplink transmission; and / or- wherein the third signaling indicates that a fallback modulation order, including n / 2-BPSK, is to be used in case of degraded channel conditions; and / or- wherein the first signaling and the third signaling are transmitted in the same message; and / or- wherein the assigned modulation and coding scheme in the third signaling is selected in accordance with the wireless device's indicated modulation (e.g., n / 2-BPSK) support when the MCS index is decoupled; and / or- wherein the wireless device determines whether to apply n / 2-BPSK or QPSK based on an additional modulation-type indicator included in the third signaling; and / or- wherein the third signaling is transmitted via a DCI message; and / or - wherein the third signaling indicates the selection of pi / 2-BPSK; and / or - wherein the subsequent transmission is an uplink transmission; and / or - wherein the subsequent transmission is a downlink transmission; and / or- wherein the wireless device dynamically selects n / 2-BPSK or QPSK for the scheduled uplink transmission based on an uplink channel-quality metric.

39. An wireless device for enhanced coverage, wherein the wireless device comprises: - a transceiver,- a processor configured for performing the method of any of the claims 1 to 38.

40. A method for providing access to a network, comprising:- receiving, by a first access device, one or more times, a second message from a first wireless device attempting to connect to the network,- transmitting, by the first access device, L third messages with L greater or equal than 1 upon reception of one or more second messages, and- performing or enabling, by the first access device, a data exchange with and / or through the first wireless device.

41. A method for providing access to a network, comprising:- receiving, by a first access device, one or more times, a second message from a first wireless device attempting to connect to the network, and- transmitting, by the first access device, an indication to a second access device, wherein the indication indicates the reception of the one or more second messages from the first wireless device.

42. A method for providing access to a network, comprising:- receiving, by a second access device, an indication from a first access device, wherein the indication indicates the reception of the one or more second messages from a first wireless device,- transmitting, by the second access device, L third messages with L greater or equal than 1 upon reception of the indication, and- performing or enabling, by the second access device, a data exchange with the first wireless device.

43. A method performed by a first access device for enhanced coverage comprising: - transmitting, by the first access device, a first configuration for performing random access through two or more beams of the first access device,- receiving, by the first access device, two or more second messages through two or more beams of the access device,- determining, by the first access device, a preferred beam for receiving an uplink message,- sending, by the first access device, an indication of the preferred beam in a third message,- receiving, by the first access device, the uplink message via the preferred beam.

44. A method performed by a first access device comprising:- transmitting, by the first access device, a first configuration for performing random access through a first access device and / or a second access device,- receiving, by the first access device, one or more second messages through one or more beams of the first access device,- determining, by the first access device, a preferred access device for completing the random access procedure, and- sending, by the first access device, a third message to the wireless device upon determining that the preferred access device is the first access device.

45. A method performed by an access device for low PAPR communication comprising: transmitting, by the access device, via a first signaling a modulation and coding, MAC, configuration whether (1) modulation information and coding information for one or more modulation and coding scheme, MCS, indices are coupled or decoupled; and / or (2) modulation information for one or more MCS indices, andtransmitting, by the access device, via a third signaling an assignment of a modulation and coding scheme for a subsequent transmission.

46. An access device for enhanced coverage, wherein the access device comprises: - a transceiver,- a processor configured for performing the method of any of the claims 40 to 45.

47. A computer program for enhanced coverage comprising computer instructions to perform the steps in the methods of any one of claims 1 to 38 or one of 40 to 45.

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