Pdsch coverage enhancement during random access procedure

Abstract

A user equipment (UE) configured for operation in a fifth-generate new radio (5GNR) network may perform a four-step random-access (4-step RACH) procedure for initial access. The UE may decode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission. For coverage enhancement during initial access, the UE may decode repetitions of the Msg4 PDSCH transmission received from a gNB in accordance with the scheduling. The repetitions of the Msg4 PDSCH transmission may be configured to the UE via higher layer signalling and / or signaled to the UE via a field of the DCI format. For communicating with the gNB via a non-terrestrial network (NTN), the DCI format and the Msg4 PDSCH transmission are received from the gNB via the NTN. When the UE is communicating with the gNB via the NTN, the Msg4 PDSCH transmission may be transmitted with repetitions for coverage enhancement.

Description

PDSCH COVERAGE ENHANCEMENT DURING RANDOM ACCESS PROCEDUREPRIORITY CLAIM

[0001] This application claims priority to United States Provisional Patent Application Serial No. 63 / 574,023, filed April 3, 2024 [reference number AG0399-Z] which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] Embodiments pertain to wireless communications. Some embodiments relate to wireless networks including 3 GPP (Third Generation Partnership Project) and fifth-generation (5G) networks including 5G new radio (NR) (or 5G-NR) networks. Some embodiments relate to sixth-generation (6G) networks.BACKGROUND

[0003] Mobile communications have evolved significantly from early voice systems to today’s highly sophisticated integrated communication platform. With the increase in different types of devices communicating with various network devices, usage of 3GPP 5G NR systems has increased. The penetration of mobile devices (user equipment or UEs) in modem society has continued to drive demand for a wide variety of networked devices in many disparate environments. 5G NR wireless systems are forthcoming and are expected to enable even greater speed, connectivity, and usability, and are expected to increase throughput, coverage, and robustness and reduce latency and operational and capital expenditures. 5G-NR networks will continue to evolve based on 3 GPP LTE- Advanced with additional potential new radio access technologies (RATs) to enrich people’s lives with seamless wirelessconnectivity solutions delivering fast, rich content and services. As current cellular network frequency is saturated, higher frequencies, such as millimeter wave (mmWave) frequency, can be beneficial due to their high bandwidth.

[0004] One issue with communicating data over a wireless network is coverage. For a cellular system, coverage is an important factor for successful operation. Compared to LTE, NR can be deployed at a relatively higher carrier frequency in frequency range 1 (FR1) (e.g., at 3.5GHz). In this case, coverage loss is expected due to larger path-loss, which makes it more challenging to maintain an adequate quality of service. Typically, uplink coverage is the bottleneck for system operation considering the low transmit power at the UE side. This is particularly an issue for cellular systems that use Non-Terrestrial Networks (NTN), where a UE is served via satellites or High-Altitude Platform Stations. Considering the significant distances between the NTN and the UE, additional coverage enhancements may be needed for NTN deployment.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 A illustrates an architecture of a network, in accordance with some embodiments.

[0006] FIG. IB and FIG. 1C illustrate a non-roaming 5G system architecture in accordance with some embodiments.

[0007] FIG. 2 illustrates a four-step random-access (4-step RACH) procedure for initial access, in accordance with some embodiments.

[0008] FIG. 3 illustrates an NTN-based NG radio access network (RAN) and Terrestrial NG-RAN, in accordance with some embodiments.

[0009] FIG. 4 illustrates a functional block diagram of a wireless communication device, in accordance with some embodiments.DETAILED DESCRIPTION

[0010] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and otherchanges. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0011] Embodiments disclosed herein provide coverage enhancement for 5GNR systems. In some embodiments, these coverage enhancements are applicable to NTN deployments although the scope of the embodiments is not limited in this respect. In some embodiments, repetitions of one or more messages for initial access that are transmitted via an NTN provide coverage enhancement during initial access. In some embodiments, repetitions of the Msg4 PDSCH transmission provide coverage enhancement during initial access via an NTN.

[0012] Some embodiments are directed to a user equipment (UE) configured for operation in a fifth-generate new radio (5G NR) network. To perform a four-step random-access (4-step RACH) procedure for initial access, the UE may encode a message three (Msg3) physical uplink shared channel (PUSCH) transmission to a gNodeB (gNB). The UE may also decode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission. For coverage enhancement during initial access, the UE may decode repetitions of the Msg4 PDSCH transmission received from a gNB in accordance with the scheduling. In these embodiments, the repetitions of the Msg4 PDSCH transmission may be configured to the UE via higher layer signalling or signaled to the UE via a field of the DCI format. In these embodiments, repetitions of the Msg4 PDSCH transmission provide coverage enhancement during initial access. In these embodiments, repetitions of the Msg4 PDSCH transmission provide coverage enhancement during initial access via an NTN. These embodiments as well as others are discussed in more detail here.

[0013] Some embodiments are directed to a gNodeB (gNB) configured for operation in a fifth-generate new radio (5GNR) network. To perform a four- step random-access (4-step RACH) procedure with a user equipment (UE) for initial access, the gNB may decode a message three (Msg3) physical uplink shared channel (PUSCH) transmission from the UE and encode a downlink control information (DCI) format scheduling a message 4 (Msg4) physicaldownlink shared channel (PDSCH) transmission. In these embodiments, the gNB may encode repetitions of the Msg4 PDSCH transmission for transmission to the UE in accordance with the scheduling. In these embodiments, the repetitions of the Msg4 PDSCH transmission may be configured to the UE via higher layer signalling and / or signaled to the UE via a field of the DCI format.

[0014] FIG. 1 A illustrates an architecture of a network in accordance with some embodiments. The network 140A is shown to include user equipment (UE) 101 and UE 102. The UE 101 and UE 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks) but may also include any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, drones, or any other computing device including a wired and / or wireless communications interface. The UE 101 and UE 102 can be collectively referred to herein as UE 101 or UE 102, and UE 101 and / or UE 102 may be used to perform one or more of the techniques disclosed herein.

[0015] In accordance with embodiments, UE 101 and / or UE 102 may be configured for operation in a fifth-generate new radio (5G NR) network. To perform a four-step random-access (4-step RACH) procedure for initial access, the UE may encode a message three (Msg3) physical uplink shared channel (PUSCH) transmission to a gNodeB (gNB). The UE may also decode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission. For coverage enhancement during initial access, the UE may decode repetitions of the Msg4 PDSCH transmission received from a gNB in accordance with the scheduling. In these embodiments, the repetitions of the Msg4 PDSCH transmission may be configured to the UE via higher layer signalling and / or signaled to the UE via a field of the DCI format. In these embodiments, repetitions of the Msg4 PDSCH transmission provide coverage enhancement during initial access.

[0016] Any of the radio links described herein (e.g., as used in the network 140 A or any other illustrated network) may operate according to any exemplary radio communication technology and / or standard.

[0017] LTE and LTE- Advanced are standards for wireless communications of high-speed data for UE such as mobile telephones. In LTE- Advanced and various wireless systems, carrier aggregation is a technology according to which multiple carrier signals operating on different frequencies may be used to carry communications for a single UE, thus increasing the bandwidth available to a single device. In some embodiments, carrier aggregation may be used where one or more component carriers operate on unlicensed frequencies.

[0018] Embodiments described herein can be used in the context of any spectrum management scheme including, for example, dedicated licensed spectrum, unlicensed spectrum, (licensed) shared spectrum (such as Licensed Shared Access (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and further frequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and further frequencies).

[0019] Embodiments described herein can also be applied to different Single Carrier or OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-based multicarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio) by allocating the OFDM carrier data bit vectors to the corresponding symbol resources.

[0020] In some embodiments, any of the UE 101 and UE 102 can comprise an Intemet-of-Things (loT) UE or a Cellular loT (CIoT) UE, which can comprise a network access layer designed for low-power loT applications utilizing short-lived UE connections. In some embodiments, any of the UE 101 and UE 102 can include a narrowband (NB) loT UE (e.g., such as an enhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An loT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or loT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An loT network includes interconnecting loT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The loT UEs may execute background applications(e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the loT network.

[0021] In some embodiments, any of the UE 101 and UE 102 can include enhanced MTC (eMTC) UEs or further enhanced MTC (FeMTC) UEs.

[0022] The UE 101 and UE 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110. The RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UE 101 and UE 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to- Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth-generation (5G) protocol, a New Radio (NR) protocol, and the like.

[0023] In an aspect, the UE 101 and UE 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

[0024] The UE 102 is shown to be configured to access an access point (AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as, for example, a connection consistent with any IEEE 802.11 protocol, according to which the AP 106 can comprise a wireless fidelity (WiFi) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0025] The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), Next Generation NodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). In some embodiments, the RAN nodes 111 and 112 can be transmission / reception points (TRPs). In instances when the RAN nodes 111 and 112 are NodeBs (e.g., eNBs or gNBs), one or more TRPs can function within the communication cell of the NodeBs. The RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro-RAN node, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node.

[0026] RAN 110 may include a terrestrial network (TN) (i.e., a Terrestrial NG-RAN) and / or a non-terrestrial network (NTN) (i.e., an NTN- based NG RAN). An example of an NTN-based NG RAN and a Terrestrial NG- RAN is illustrated in FIG. 3.

[0027] Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UE 101 and UE 102. In some embodiments, any of the RAN nodes 111 and 112 can fulfill various logical functions for the RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management. In an example, any of the RAN nodes 111 and / or 112 can be a new generation Node-B (gNB), an evolved node-B (eNB), or another type of RAN node.

[0028] The RAN 110 is shown to be communicatively coupled to a core network (CN) 120 via an SI interface 113. In embodiments, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN (e.g., as illustrated in reference to FIGS. 1B-1C). In this aspect, the SI interface 113 is split into two parts: the Sl-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the SI -mobility management entity (MME) interface115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs 121.

[0029] In this aspect, the CN 120 comprises the MMEs 121, the S-GW 122, the Packet Data Network (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility embodiments in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing / roaming, authentication, authorization, naming / addressing resolution, location dependencies, etc.

[0030] The S-GW 122 may terminate the SI interface 113 towards the RAN 110, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities of the S-GW 122 may include a lawful intercept, charging, and some policy enforcement.

[0031] The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123 may route data packets between the CN 120 and external networks such as a network including the application server 184 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. The P-GW 123 can also communicate data to other external networks 131 A, which can include the Internet, IP multimedia subsystem (IPS) network, and other networks. Generally, the application server 184 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this aspect, the P-GW 123 is shown to be communicatively coupled to an application server 184 via an IP interface 125. The application server 184 can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol(VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UE 101 and UE 102 via the CN 120.

[0032] The P-GW 123 may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, in some embodiments, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with a local breakout of traffic, there may be two PCRFs associated with a UE's IP- CAN session: a Home PCRF (H-PCRF) within an HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be communicatively coupled to the application server 184 via the P- GW 123.

[0033] In some embodiments, the communication network 140 A can be an loT network or a 5G network, including 5G new radio network using communications in the licensed (5GNR) and the unlicensed (5GNR-U) spectrum. One of the current enablers of loT is the narrowband-IoT (NB-IoT).

[0034] An NG system architecture can include the RAN 110 and a 5G network core (5GC). In these embodiments, the RAN 110 can include a plurality of nodes, such as gNBs and NG-eNBs. The CN 120 (e.g., a 5G core network or 5GC) can include an access and mobility function (AMF) and / or a user plane function (UPF). The AMF and the UPF can be communicatively coupled to the gNBs and the NG-eNBs via NG interfaces. More specifically, in some embodiments, the gNBs and the NG-eNBs can be connected to the AMF by NG- C interfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBs can be coupled to each other via Xn interfaces.

[0035] In some embodiments, the NG system architecture can use reference points between various nodes as provided by 3GPP Technical Specification (TS) 23.501 (e.g., V15.4.0, 2018-12). In some embodiments, each of the gNBs and the NG-eNBs can be implemented as a base station, a mobile edge server, a small cell, a home eNB, and so forth. In some embodiments, a gNB can be a master node (MN) and NG-eNB can be a secondary node (SN) in a 5G architecture.

[0036] FIG. IB illustrates a non-roaming 5G system architecture in accordance with some embodiments. Referring to FIG. IB, there is illustrated a 5G system architecture 140B in a reference point representation. More specifically, UE 102 can be in communication with RAN 110 as well as one or more other 5G core (5GC) network entities. The 5G system architecture 140B includes a plurality of network functions (NFs), such as access and mobility management function (AMF) 132, session management function (SMF) 136, policy control function (PCF) 148, application function (AF) 150, user plane function (UPF) 134, network slice selection function (NSSF) 142, authentication server function (AUSF) 144, and unified data management (UDM) / home subscriber server (HSS) 146. The UPF 134 can provide a connection to a data network (DN) 152, which can include, for example, operator services, Internet access, or third-party services. The AMF 132 can be used to manage access control and mobility and can also include network slice selection functionality. The SMF 136 can be configured to set up and manage various sessions according to network policy. The UPF 134 can be deployed in one or more configurations according to the desired service type. The PCF 148 can be configured to provide a policy framework using network slicing, mobility management, and roaming (similar to PCRF in a 4G communication system). The UDM can be configured to store subscriber profiles and data (similar to an HSS in a 4G communication system).

[0037] In some embodiments, the 5G system architecture 140B includes an IP multimedia subsystem (IMS) 168B as well as a plurality of IP multimedia core network subsystem entities, such as call session control functions (CSCFs). More specifically, the IMS 168B includes a CSCF, which can act as a proxy CSCF (P-CSCF) 162B, a serving CSCF (S-CSCF) 164B, an emergency CSCF (E-CSCF) (not illustrated in FIG. IB), or interrogating CSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the first contact point for the UE 102 within the IM subsystem (IMS) 168B. The S-CSCF 164B can be configured to handle the session states in the network, and the E-CSCF can be configured to handle certain embodiments of emergency sessions such as routing an emergency request to the correct emergency center or PSAP. The I-CSCF 166B can be configured to function as the contact point within an operator's networkfor all IMS connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator's service area. In some embodiments, the I-CSCF 166B can be connected to another IP multimedia network 170E, e.g. an IMS operated by a different network operator.

[0038] In some embodiments, the UDM / HSS 146 can be coupled to an application server 160E, which can include a telephony application server (TAS) or another application server (AS). The AS 160B can be coupled to the IMS 168B via the S-CSCF 164B or the I-CSCF 166B.

[0039] A reference point representation shows that interaction can exist between corresponding NF services. For example, FIG. IB illustrates the following reference points: N1 (between the UE 102 and the AMF 132), N2 (between the RAN 110 and the AMF 132), N3 (between the RAN 110 and the UPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF 148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152), N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM / HSS 146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown), N10 (between the UDM / HSS 146 and the SMF 136, not shown), Ni l (between the AMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and the AMF 132, not shown), N13 (between the AUSF 144 and the UDM / HSS 146, not shown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148 and the AMF 132 in case of a non-roaming scenario, or between the PCF 148 and a visited network and AMF 132 in case of a roaming scenario, not shown), N16 (between two SMFs, not shown), and N22 (between AMF 132 and NSSF 142, not shown). Other reference point representations not shown in FIG. IB can also be used.

[0040] FIG. 1C illustrates a 5G system architecture 140C and a servicebased representation. In addition to the network entities illustrated in FIG. IB, system architecture 140C can also include a network exposure function (NEF) 154 and a network repository function (NRF) 156. In some embodiments, 5G system architectures can be service-based and interaction between network functions can be represented by corresponding point-to-point reference points Ni or as service-based interfaces.

[0041] In some embodiments, as illustrated in FIG. 1C, service-based representations can be used to represent network functions within the control plane that enable other authorized network functions to access their services. In this regard, 5G system architecture 140C can include the following service-based interfaces: Namf 158H (a service-based interface exhibited by the AMF 132), Nsmf 1581 (a service-based interface exhibited by the SMF 136), Nnef 158B (a service-based interface exhibited by the NEF 154), Npcf 158D (a service-based interface exhibited by the PCF 148), a Nudm 158E (a service-based interface exhibited by the UDM / HSS 146), Naf 158F (a service-based interface exhibited by the AF 150), Nnrf 158C (a service-based interface exhibited by the NRF 156), Nnssf 158A (a service-based interface exhibited by the NSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF 144). Other servicebased interfaces (e.g., Nudr, N5g-eir, and Nudsf) not shown in FIG. 1C can also be used.

[0042] In some embodiments, any of the UEs or base stations described in connection with FIGS. 1 A-1C can be configured to perform the functionalities described herein.

[0043] Mobile communication has evolved significantly from early voice systems to today’s highly sophisticated integrated communication platform. The next generation wireless communication system, 5G, or new radio (NR) will provide access to information and sharing of data anywhere, anytime by various users and applications. NR is expected to be a unified network / system that targets to meet vastly different and sometimes conflicting performance dimensions and services. Such diverse multi-dimensional requirements are driven by different services and applications. In general, NR will evolve based on 3 GPP LTE- Advanced with additional potential new Radio Access Technologies (RATs) to enrich people's lives with better, simple, and seamless wireless connectivity solutions. NR will enable everything connected by wireless and deliver fast, rich content and services.

[0044] Rel-15 NR systems are designed to operate on the licensed spectrum. The NR-unlicensed (NR-U), a short-hand notation of the NR-based access to unlicensed spectrum, is a technology that enables the operation of NR systems on the unlicensed spectrum.

[0045] In NR Rel-15, a 4-step procedure was defined for initial access. In the first step, UE transmits physical random-access channel (PRACH) in the uplink by randomly selecting one preamble signature, which would allow gNB to estimate the delay between gNB and UE for subsequent UL timing adjustment. Subsequently, in the second step, gNB feedback the random-access response (RAR) which carries timing advanced (TA) command information and uplink grant for the uplink transmission in the third step. The UE expects to receive the RAR within a time window, of which the start and end are configured by the gNB via system information block (SIB). The UE then sends Msg3 based on the uplink grant in the RAR. The Msg3 may include a physical uplink shared channel (PUSCH). The gNB then sends a Msg4 for contention resolution.

[0046] For an NTN deployment, coverage of physical downlink shared channel (PDSCH) transmissions during 4-step RACH procedure and / or 2-step RACH procedure may need to be improved to meet the targeted requirements. In this case, certain mechanism may need to be defined to enhance the coverage of Msg2 and Msg4 PDSCH transmissions during random access procedure.

[0047] In some embodiments, PDSCH coverage enhancement is provided during the random-access procedure. In some embodiments, coverage enhancement is provided for Msg2 PDSCH for initial access. In some embodiments, coverage enhancement is provided for Msg4 PDSCH for initial access. In some embodiments, conditions on request of Msg2 / Msg4 PDSCH repetitions during random access are provided.

[0048] Coverage enhancement for Msg2 PDSCH for initial access

[0049] As mentioned above, for an NTN deployment, coverage of physical downlink shared channel (PDSCH) transmissions during 4-step RACH procedure and / or 2-step RACH procedure may need to be improved to meet the targeted requirements. In this case, certain mechanism may need to be defined to enhance the coverage of Msg2 and Msg4 PDSCH transmissions during randomaccess procedure. Embodiments of coverage enhancement for Msg2 PDSCH for initial access are described below.

[0050] In some embodiments, UE may report the UE capability on the support of the repetition of Msg2 physical downlink shared channel (PDSCH), MsgB PDSCH and / or Msg4 PDSCH transmission to the gNB using physical random-access channel (PRACH) resource partitioning. In some embodiments, a set of PRACH resources may be configured for the UE (via SIB1) to indicate the support of the repetition of Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH. Similarly, UE may transmit request for repetition of Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH transmission to the gNB using PRACH resource partitioning.

[0051] In addition, a UE may transmit the PRACH using the separate PRACH preambles in case of shared PRACH occasions (RO) or with separate ROs that are different from the PRACH resources for the case when UE does not support Msg2 and Msg4 PDSCH repetitions.

[0052] In some embodiments, when UE transmits the PRACH with repetitions using the PRACH resources that are configured for PRACH repetitions, this may indicate that UE supports the Msg2 and Msg4 PDSCH repetitions.

[0053] Similarly, when UE transmits the Msg3 PUSCH with repetitions or indicates the supports of Msg3 PUSCH repetitions, this may indicate that UE supports the Msg4 PDSCH repetitions or that UE requests the Msg4 PDSCH repetitions.

[0054] In some embodiments, the UE request may include information about the number of repetitions recommended by the UE for DL transmission.

[0055] In another option, UE may indicate the support of Msg4 PDSCH repetitions in the Medium Access Control - Control Element (MAC-CE) in Msg3 PUSCH. In this case, a logic ID (LCID) may be defined to indicate that the MAC-CE is used to carry the indication of support of Msg4 PDSCH repetitions.

[0056] FIG. 2 illustrates a four-step random-access (4-step RACH) procedure for initial access, in accordance with some embodiments. The 4-stepRACH) procedure 200 may be performed between a UE 102 and a gNB 210 for initial access. FIG. 2 illustrates a 4-step RACH procedure that may support Msg2 PDSCH repetitions and / or Msg4 PDSCH repetitions for coverage enhancement during initial access. In operation 202, a UE 102 may transmit a PRACH preamble using a PRACH resource that is configured to indicate support of Msg2 and Msg4 PDSCH repetitions. In operation 204, a gNB 210 may indicate the number of repetitions for Msg2 PDSCH in the DCI format 1 0 with CRC scrambled with RA-RNTI and may transmits the Msg2 PDSCH using the indicated number of repetitions. In operation 206, the UE may transmit the Msg3 PUSCH with or without repetitions that carries L2 and L3 message with contention resolution ID. In operation 208, the gNB 210 may indicate the number of repetitions for Msg4 PDSCH in the DCI format 1 0 with CRC scrambled with TC-RNTI and may transmit the Msg4 PDSCH using the indicated number of repetitions.

[0057] In some embodiments, a field for the number of repetitions of Msg2 PDSCH transmission may be explicitly included in the downlink control information (DCI) for scheduling Msg2 PDSCH. In particular, the number of repetitions for the Msg2 PDSCH transmission may be included in the DCI format 1 0 with Cyclic Redundancy Check (CRC) scrambled by Random Access - Radio Network Temporary Identifier (RA-RNTI) for 4-step RACH procedure.

[0058] In these embodiments, after the UE sends Msgl PRACH, UE may start to monitor the DCI in a CORESET / search space set during a randomaccess response (RAR) window. UE may attempt to decode a DCI within the RAR window.

[0059] In some embodiments, a set of the number of repetitions for Msg2 PDSCH transmissions may be configured by higher layers via NR remaining minimum system information (RMSI), NR other system information (OSI) or dedicated radio resource control (RRC) signalling. Furthermore, one field may be included in the DCI format 1 0 with CRC scrambled by RA-RNTI to indicate the number of repetitions from the set of the number of repetitions for Msg2 PDSCH transmission. If the set of the number of repetitions is not configured, a default set of the number of repetitions for Msg2 PDSCH transmissions may bepredefined. In some embodiments, after the UE successfully detects an SSB, it will start to look for system information, like RMSI (= SIB1), OSI (= SIBx). After initial access, UE may receive the dedicated RRC signalling from gNB, (mostly would be UE specific RRC configuration)

[0060] In some embodiments, a repetition number of one may be included in the set of the number of repetitions for Msg2 PDSCH transmission (i.e., to indicate a single transmission of the Msg2 PDSCH (Msg2 PDSCH transmission without repetition)).

[0061] In some embodiments, when a repetition number of one is configured for Msg2 PDSCH transmission, the field in the DCI for the number of repetitions for Msg2 PDSCH transmissions may not be present. In this case, the number of repetitions for Msg2 PDSCH transmissions may be determined based on the configured number of repetitions. The field in the DCI for the number of repetitions for Msg2 PDSCH transmissions may be present when more than one number of repetitions is configured for Msg2 PDSCH transmissions. DCI format 1 0 is applicable to scheduling a PDSCH and may therefore be used to indicate either the number of repetitions for Msg2 PDSCH transmissions or the number of repetitions for Msg4 PDSCH transmissions.

[0062] The following text in clause 7.3.1.2.1 of 3GPP TS 38.212 for the scheduling of PDSCH may be updated to include the number of repetitions as shown below. The Reserved bits may be updated as well (as shown below) since some of the reserved bits will be used for indicating the number of repetitions.7.3.1.2.1 Format 1 0DCI format 1 0 is used for the scheduling of PDSCH in one DL cell.The following information is transmitted by means of the DCI format l_0 with CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI:- Frequency domain resource assignment -bitsJV^"BWPis the size of CORESET 0 if CORESET 0 is configured for the cell and .\'(B"B'VPis the size of initial DL bandwidth part if CORESET 0 is not configured for the cellTime domain resource assignment - 4 bits as defined in Clause 5. 1.2.1 of [6, TS38.214]- VRB-to-PRB mapping - 1 bit according to Table 7.3.1.2.2-5- Modulation and coding scheme - 5 bits as defined in Clause 5.1.3 of [6, TS38.214], using Table 5.1.3.1-1TB scaling - 2 bits as defined in Clause 5.1.3.2 of [6, TS38.214]- LSBs of SFN - 2 bits for the DCI format l_0 with CRC scrambled by MsgB-RNTI as defined in Clause 8.2A of [5, TS 38.213] if msgB- responseWindow is configured to be larger than 10 ms; or 2 bits for the DCI format l_0 with CRC scrambled by RA-RNTI as defined in Clause 8.2 of [5, TS 38.213] for operation in a cell with shared spectrum channel access if ra-ResponseWindcrw or ra-ResponseWindow-vl610 is configured to be larger than 10 ms; 0 bit otherwise- Number of repetitions - X bits- Reserved bits - (16 - A - X) bits for operation in a cell without shared spectrum access in frequency range 1 and frequency range 2-1, (18 - A - X) for operation in a cell with shared spectrum access in frequency range 1 or for operation in a cell in frequency range 2-2, where the value of A is the number of bits for the field of 'L SBs of SFN' as defined above

[0063] In some embodiments, number of repetitions may be implicitly determined in the DCI for scheduling Msg2 PDSCH. In some embodiments, X most significant bits (MSB) or least significant bits (LSB) of the modulation and coding scheme (MCS) field in the DCI format 1 0 with CRC scrambled by RA- RNTI may be used to indicate the number the repetitions for Msg2 PDSCH transmission. In addition, a set of the number of repetitions may be configured by higher layers via RMSI, OSI, or RRC signalling. Further, X MSBs or LSBs of the MCS field in the DCI format with CRC scrambled by RA-RNTI may be used to indicate the number the repetitions from the set of the number of repetitions for Msg2 PDSCH transmission. Further, a set of MCS indexes may be configured by higher layers via RMSI, OSI, or RRC signalling. For Msg2 PDSCH transmission with repetitions, the MCS field is used to indicate one MCS from the set of MCS indexes that are configured by higher layers. In one example, 2 MSBs of MCS field in the DCI format 1 0 with CRC scrambled by RA-TNTI may be repurposed to indicate the number of repetitions for Msg2 PDSCH transmission. In addition, the remaining 3 LSBs of the MCS field may be used to indicate the MCS from the 8 MCS indexes that are configured by higher layers.

[0064] In some embodiments, one parameter may be included in a default PDSCH time domain resource allocation (e.g., in Table 5.1.2.1.1-2 and Table 5.1.2.1.1-3 in TS38.214) to indicate the number of repetitions for Msg2PDSCH transmission. In these embodiments, when UE indicates the support of Msg2 PDSCH repetitions, UE may use the new table that includes the parameter with the number of repetitions for Msg2 PDSCH transmission to determine the time domain resource allocation of Msg2 PDSCH transmission.

[0065] These embodiments may apply for the transmission of MsgB PDSCH which is scheduled by PDCCH format 1 0 with CRC scrambled by MsgB-RNTI for 2-step RACH procedure, although the scope of the embodiments is not limited in this respect.

[0066] Coverage enhancement for Msg4 PDSCH for initial access

[0067] Embodiments of coverage enhancement for Msg4 PDSCH for initial access are provided below:

[0068] In some embodiments, one field for the number of repetitions for Msg4 PDSCH transmissions may be included in the DCI format for scheduling Msg4 PDSCH transmission. In particular, the number of repetitions for the Msg4 PDSCH transmission may be included in the DCI format 1 0 with CRC scrambled by Temporary Cell - Radio Network Temporary Identifier (TC-RNTI) for 4-step RACH procedure. In these embodiments, the UE may start to monitor CORESET / search space to decode DCI (for Msg4 PDSCH scheduling) after it sends Msg3.

[0069] In some embodiments, a set of the number of repetitions for Msg4 PDSCH transmissions may be configured by higher layers via RMSI, OSI, or RRC signalling. Further, one field may be included in the DCI format 1 0 with CRC scrambled by TC-RNTI to indicate the number of repetitions from the set of the number of repetitions for Msg4 PDSCH transmission. If the set of the number of repetitions is not configured, a default set of the number of repetitions for Msg4 PDSCH transmissions may be predefined in the specification. As a further extension, the same set of number of repetitions for Msg2 PDSCH transmission may be configured or predefined for that of Msg4 PDSCH transmission. In some embodiments, repetition number of one may be included in the set of the number of repetitions for Msg4 PDSCH transmission.

[0070] In some embodiments, when one number of repetitions is configured for Msg4 PDSCH transmission, the field in the DCI for the number of repetitions for Msg4 PDSCH transmissions may not be present. In this case, the number of repetitions for Msg4 PDSCH transmissions is determined based on the configured number of repetitions. The field in the DCI for the number of repetitions for Msg4 PDSCH transmissions may be present when more than one number of repetitions is configured for Msg2 PDSCH transmissions. In some embodiments, number of repetitions may be implicitly determined in the DCI for scheduling Msg4 PDSCH.

[0071] In some embodiments, X most significant bits (MSB) or least significant bits (LSB) of the modulation and coding scheme (MCS) field in the DCI format 1 0 with CRC scrambled by RX-RNTI may be used to indicate the number the repetitions for Msg3 PDSCH transmission. In addition, a set of the number of repetitions may be configured by higher layers via RMSI, OSI, or RRC signalling. Further, X MSBs or LSBs of the MCS field in the DCI format with CRC scrambled by TC-RNTI may be used to indicate the number the repetitions from the set of the number of repetitions for Msg4 PDSCH transmission. Further, a set of MCS indexes may be configured by higher layers via RMSI, OSI, or RRC signalling. For Msg2 PDSCH transmission with repetitions, the MCS field is used to indicate one MCS from the set of MCS indexes that are configured by higher layers. In one example, 2 MSBs of MCS field in the DCI format 1 0 with CRC scrambled by RA-TNTI may be repurposed to indicate the number of repetitions for Msg2 PDSCH transmission. In addition, the remaining 3 LSBs of the MCS field may be used to indicate the MCS from the 8 MCS indexes that are configured by higher layers.

[0072] In some embodiments, one parameter may be included in the default PDSCH time domain resource allocation (e.g., in Table 5.1.2.1.1-2 and Table 5.1.2.1.1-3 of TS38.214) to indicate the number of repetitions for Msg4 PDSCH transmission. In this case, when UE indicates the support of Msg4 PDSCH repetition, UE may use the new table that includes the parameter with the number of repetitions for Msg4 PDSCH transmission to determine the time domain resource allocation of Msg4 PDSCH transmission.

[0073] In some embodiments, an association between the number of repetitions for PRACH or Msg3 PUSCH transmissions and the number of repetitions for Msg4 PUSCH transmissions may be defined. In this case, the association may be explicitly configured by higher layers via RMSI, OSI, or RRC signalling, or predefined in the specifications.

[0074] In some embodiments, a one-to-one association between the number of repetitions for PRACH or Msg3 PUSCH transmissions and the number of repetitions for Msg4 PUSCH transmissions may be defined. In particular, a first number of repetitions for PRACH or Msg3 PUSCH transmissions is associated with a first number of repetitions for Msg4 PUSCH transmissions, a second number of repetitions for PRACH or Msg3 PUSCH transmissions is associated with a second number of repetitions for Msg4 PUSCH transmissions, and so on. In this case, when UE transmits PRACH or Msg3 PUSCH with a first number of repetitions, gNB may use the associated number of repetitions for Msg4 transmissions, and so on.

[0075] In some embodiments, a one-to-many association between the number of repetitions for PRACH or Msg3 PUSCH transmissions and the number of repetitions for Msg4 PUSCH transmissions may be defined. In particular, a first number of repetitions for PRACH or Msg3 PUSCH transmissions is associated with a first set of the number of repetitions for Msg4 PUSCH transmissions, a second number of repetitions for PRACH or Msg3 PUSCH transmissions is associated with a second set of number of repetitions for Msg4 PUSCH transmissions, and so on. In this case, one field in the DCI may be explicitly included or repurposed to indicate the number of repetitions for Msg4 PDSCH transmissions from the associated set of number of repetitions.

[0076] In some embodiments, for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by C-RNTI, one field in the DCI format 1 0 may be explicitly included or repurposed to indicate the number of repetitions for the PDSCH transmissions.

[0077] In some embodiments, one parameter in the time domain resource allocation table for PDSCH transmission may be included to indicate the number of repetitions for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by C-RNTI.

[0078] In some embodiments, the number of repetitions for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by C- RNTI is associated with the number of repetitions for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by TC-RNTI. In one example, a same number of repetitions for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by TC-RNTI applies to the number of repetitions for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by C-RNTI. In some embodiments, this may apply for the case before UE receives the RRC configuration from the gNB. In one example, this may include the PDSCH transmission before RRC connection setup.

[0079] Conditions on request of Msg2 / Msg4 PDSCH repetitions during random access

[0080] Embodiments of conditions on request of Msg2 / Msg4 PDSCH repetitions during random access are provided below:

[0081] In some embodiments, UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition only if certain condition is met.

[0082] In some embodiments, UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if RSRP (Reference Signal Received Power) measured at the UE is lower than RSRP threshold. Further, the RSRP threshold is configured by higher layers via RMSI, OSI, or RRC signalling. The RSRP may correspond to higher layer filtered RSRP, LI -RSRP and / or SS-RSRP.

[0083] In some embodiments, UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if RSRQ (Reference Signal Received Quality) measured at the UE is lower than RSRQ threshold. Further, the RSRQ threshold is configured by higher layers via RMSI, OSI, or RRC signalling. The RSRQ may correspond to higher layer filtered RSRQ and / or SS- RSRQ.

[0084] Further, UE may transmit request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if SINR (Signal-to-Noise-Ratio)measured at the UE is lower than SINK threshold. Further, the SINK threshold is configured by higher layers via RMSI, OSI, or RRC signalling. The SINK may correspond to higher layer filtered SINK, Ll-SINR and / or SS-SINR.

[0085] Additionally, UE may transmit the request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if hypothetical PDSCH BLER (Block Error Rate) measured at the UE is higher than BLER threshold. Further, the BLER threshold is configured by higher layers via RMSI, OSI, or RRC signalling.

[0086] In some embodiments, hypothetical BLER is calculated for hypothetical PDSCH transmission with number of repetitions N, where N may be configured by higher layers via RMSI, OSI or RRC signaling. Further, multiple hypothetical BLER values are calculated for different number of repetitions and UE determines the number of repetitions recommended for PDSCH transmission based on maximum hypothetical BLER value lower than the BLER threshold. Further, UE may transmit a request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if the CQI measured at the UE is lower than a CQI threshold. Further, the CQI threshold may be configured by higher layers via RMSI, OSI, or RRC signalling.

[0087] FIG. 3 illustrates an NTN-based NG RAN and Terrestrial NG- RAN, in accordance with some embodiments. As illustrated in FIG. 3, UE 102 may communicate with NTN-based NG RAN 302 via a NR-Uu interface. UE 102 may may also communicate with Terrestrial NG RAN 304 via a NR-Uu interface. The NTN-based NG RAN 302 may at least one of a satellite and a high-altitude platform station configured to provide communications between the UE 102 and a gNB 210. In these embodiments, a satellite and / or a high- altitude platform station act as a repeater.

[0088] In accordance with embodiments, UE 102 may be configured for operation in a fifth-generate new radio (5GNR) network. To perform a four-step random-access (4-step RACH) procedure for initial access, the UE may encode a message three (Msg3) physical uplink shared channel (PUSCH) transmission to a gNodeB (gNB). The UE may also decode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission. For coverage enhancement during initial access, the UEmay decode repetitions of the Msg4 PDSCH transmission received from a gNB in accordance with the scheduling. In these embodiments, the repetitions of the Msg4 PDSCH transmission may be configured to the UE via higher layer signalling and / or signaled to the UE via a field of the DCI format. In these embodiments, repetitions of the Msg4 PDSCH transmission provide coverage enhancement during initial access.

[0089] In some embodiments, when the number of the repetitions of the Msg4 PDSCH is signaled to the UE via the field in the DCI format, the DCI format is a DCI format 1 0 with Cyclic Redundancy Check (CRC) bits scrambled with a Temporary Cell Radio Network Temporary Identifier (TC- RNTI). In these embodiments, when the number of the repetitions of the Msg4 PDSCH is configured via the higher layer signalling, the higher layer signalling indicates a set of numbers of repetitions and the field in the DCI format indicates the number of repetitions for the Msg4 PDSCH from the set.

[0090] In some embodiments, when the field in the DCI format that indicates the number of repetitions for the Msg4 PDSCH is not present, the processing circuitry is configured to decode the Msg4 PDSCH transmission received from the gNB without repetitions. In some other embodiments, the field in the DCI format that indicates the number of repetitions for the Msg4 PDSCH may indicate one indicating that the Msg4 PDSCH transmission received from the gNB without repetitions.

[0091] In some embodiments, the UE may be configured to transmit the Msg3 PUSCH transmission with repetitions to indicate that the UE supports repetition of the Msg4 PDSCH transmission.

[0092] In some embodiments, the UE may be configured to encode the Msg3 PUSCH transmission with a Medium Access Control - Control Element (MAC-CE) that indicates that the UE supports repetition of the Msg4 PDSCH transmission during the 4-step RACH procedure performed for initial access. In these embodiments, a logic ID (LCID) may be used to indicate that the MAC-CE is used to carry the indication of support of Msg4 PDSCH repetitions, although the scope of the embodiments is not limited in this respect.

[0093]

[0094] In some embodiments, the UE is configured to encode a UE capability information element (IE) for transmission to the gNB that indicates that the UE supports repetition of the Msg4 PDSCH transmission during the 4- step RACH procedure performed for initial access.

[0095] In some embodiments, the UE is configured to encode a request for repetition of the Msg4 PDSCH transmission for transmission to the gNB during the 4-step RACH procedure when a signal quality condition determined at the UE is below a threshold, the request for repetition of the Msg4 PDSCH transmission being indicated in the Msg3 PUSCH transmission.

[0096] In some embodiments, as part of the 4-step RACH procedure, the processing circuitry is further configured to encode a message one (Msgl) physical random-access channel (PRACH) transmission to the gNB for initial access, the Msgl PRACH transmission comprising one or more PRACH preambles transmitted in one or more PRACH occasions (ROs) and decode a message two (Msg2) PDSCH random access response (RAR) transmission received from the gNB, the Msg2 PDSCH including timing advance (TA) information. In these embodiments, the Msgl PRACH transmission is configured to indicate whether the UE supports repetition of at least one of repetition of the Msg2 PDSCH transmission during the 4-step RACH procedure performed for initial access; and repetition of the Msg4 PDSCH transmission during the 4-step RACH procedure performed for initial access.

[0097] In some embodiments, to indicate that the UE does not support repetitions of the Msg2 PDSCH, the processing circuity is to configure the UE to transmit the Msgl PRACH transmission using PRACH resources that are configured to the UE via higher layer signalling. In these embodiments, to indicate that the UE supports repetitions of the Msg2 PDSCH, the processing circuity is to configure the UE to transmit the Msgl PRACH transmission using separate PRACH preambles for shared PRACH occasions (RO) or transmit the Msgl PRACH transmission using separate ROs that are different from the configured PRACH resources.

[0098] In some embodiments, the transmission of the Msgl PRACH transmission using PRACH resources that are configured to the UE for PRACHrepetition may also indicate that the UE supports repetition of the Msg4 PDSCH transmission, although the scope of the embodiments is no limited this respect.

[0099] In some embodiments, for communicating with the gNB via a non-terrestrial network (NTN) (e.g., NTN-based NG RAN 302 (FIG. 3), the DCI format and the Msg4 PDSCH transmission are received from the gNB via the NTN. In these embodiments, when the UE is communicating with the gNB via the NTN, the Msg4 PDSCH transmission is transmitted with repetitions for coverage enhancement. In these embodiments, when the UE is communicating with the gNB via a terrestrial network (e.g. Terrestrial NG RAN 304 FIG. 3), the Msg4 PDSCH transmission is transmitted without repetitions.

[0100] In some embodiments, the NTN comprises at least one of a satellite and a high-altitude platform station configured to provide communications between the UE and the gNB. In these embodiments, the satellite and high-altitude platform station may act as a repeater, relay or bent pipe, although the scope of the embodiments is not limited in this respect as some of the functionality of a gNB may be performed by the satellite or the high- altitude platform station.

[0101] Some embodiments are directed to a gNodeB (gNB) configured for operation in a fifth-generate new radio (5GNR) network. To perform a four- step random-access (4-step RACH) procedure with a user equipment (UE) for initial access, the gNB may decode a message three (Msg3) physical uplink shared channel (PUSCH) transmission from the UE and encode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission. In these embodiments, the gNB may encode repetitions of the Msg4 PDSCH transmission for transmission to the UE in accordance with the scheduling. In these embodiments, the repetitions of the Msg4 PDSCH transmission may be configured to the UE via higher layer signalling and / or signaled to the UE via a field of the DCI format.

[0102] FIG. 4 illustrates a functional block diagram of a wireless communication device, in accordance with some embodiments. Wireless communication device 400 may be suitable for use as a UE or gNB configured for operation in a 5GNR or 6G network. Some embodiments are directed to anapparatus of a UE or gNB comprising processing circuitry and memory configured for operation in a 5GNR or 6G network.

[0103] Wireless communication device 400 may also be suitable for use as a handheld device, a mobile device, a cellular telephone, a smartphone, a tablet, a netbook, a wireless terminal, a laptop computer, a wearable computer device, a femtocell, a high data rate (HDR) subscriber device, an access point, an access terminal, or other personal communication system (PCS) device.

[0104] The wireless communication device 400 may include communications circuitry 402 and a transceiver 410 for transmitting and receiving signals to and from other communication devices using one or more antennas 401. The communications circuitry 402 may include circuitry that can operate the physical layer (PHY) communications and / or medium access control (MAC) communications for controlling access to the wireless medium, and / or any other communications layers for transmitting and receiving signals. The wireless communication device 400 may also include processing circuitry 406 and memory 408 arranged to perform the operations described herein. In some embodiments, the communications circuitry 402 and the processing circuitry 406 may be configured to perform operations detailed in the above figures, diagrams, and flows.

[0105] In accordance with some embodiments, the communications circuitry 402 may be arranged to contend for a wireless medium and configure frames or packets for communicating over the wireless medium. The communications circuitry 402 may be arranged to transmit and receive signals. The communications circuitry 402 may also include circuitry for modulation / demodulation, upconversion / downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry 406 of the wireless communication device 400 may include one or more processors. In other embodiments, two or more antennas 401 may be coupled to the communications circuitry 402 arranged for sending and receiving signals. The memory 408 may store information for configuring the processing circuitry 406 to perform operations for configuring and transmitting message frames and performing the various operations described herein. The memory 408 may include any type of memory, including non-transitory memory, for storinginformation in a form readable by a machine (e.g., a computer). For example, the memory 408 may include a computer-readable storage device, read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices and other storage devices and media.

[0106] In some embodiments, the wireless communication device 400 may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that may receive and / or transmit information wirelessly.

[0107] In some embodiments, the wireless communication device 400 may include one or more antennas 401. The antennas 401 may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated for spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting device.

[0108] In some embodiments, the wireless communication device 400 may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0109] Although the wireless communication device 400 is illustrated as having several separate functional elements, two or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digitalsignal processors (DSPs), and / or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radiofrequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of the wireless communication device 400 may refer to one or more processes operating on one or more processing elements.

[0110] Embodiments may be implemented in one or a combination of hardware, firmware and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include readonly memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device. Some embodiments are directed to a non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a user equipment (UE) configured for operation in a fifth-generate new radio (5G NR) network.

[0111] Examples:

[0112] Example 1 : A system and method of wireless communication for a fifth generation (5G) or new radio (NR) system: indicating, by gNB, the number of repetitions for Msg2 and Msg4 physical downlink shared channel (PDSCH) in downlink control information (DCI); and transmitting, by gNB, the Msg2 and Msg4 PDSCH in accordance with the indicated number of repetitions.

[0113] Example 2: The method of example 1, wherein a set of physical random-access channel (PRACH) resources to indicate the support of Msg2 and Msg4 PDSCH repetitions during random access procedure are configured bygNB; where UE transmits a PRACH preamble using the configured PRACH resource to indicate the support of Msg2 and Msg4 PDSCH repetitions.

[0114] Example 3: The method of example 1, wherein the DCI format is the DCI format 1 0 with Cyclic Redundancy Check (CRC) scrambled by Random Access - Radio Network Temporary Identifier (RA-RNTI), MsgB- RNTI and / or temporary cell -RNTI (TC-RNTI).

[0115] Example 4: The method of example 1, wherein UE may indicate the support of Msg4 PDSCH repetitions in the Medium Access Control - Control Element (MAC-CE) in Msg3 PUSCH.

[0116] Example 5: The method of example 1, wherein one field for the number of repetitions of Msg2 PDSCH transmission may be explicitly included in the downlink control information (DCI) for scheduling Msg2 PDSCH.

[0117] Example 6: The method of example 1, wherein a set of the number of repetitions for Msg2 PDSCH transmissions may be configured by higher layers via NR remaining minimum system information (RMSI), NR other system information (OSI) or dedicated radio resource control (RRC) signalling.

[0118] Example 7: The method of example 1, wherein when one number of repetitions is configured for Msg2 PDSCH transmission, the field in the DCI for the number of repetitions for Msg2 PDSCH transmissions may not be present.

[0119] Example 8: The method of example 1, wherein X most significant bits (MSB) or least significant bits (LSB) of the modulation and coding scheme (MCS) field in the DCI format 1 0 with CRC scrambled by RA-RNTI may be used to indicate the number the repetitions for Msg2 PDSCH transmission.

[0120] Example 9: The method of example 1, wherein one parameter may be included in the default PDSCH time domain resource allocation A to indicate the number of repetitions for Msg2 PDSCH transmission.

[0121] Example 10: The method of example 1, wherein one field for the number of repetitions for Msg4 PDSCH transmissions may be included in the DCI format for scheduling Msg4 PDSCH transmission.

[0122] Example 11 : The method of example 1, wherein a set of the number of repetitions for Msg4 PDSCH transmissions may be configured by higher layers via RMSI, OSI, or RRC signalling.

[0123] Example 12: The method of example 1, wherein when one number of repetitions is configured for Msg4 PDSCH transmission, the field in the DCI for the number of repetitions for Msg4 PDSCH transmissions may not be present.

[0124] Example 13: The method of example 1, wherein X most significant bits (MSB) or least significant bits (LSB) of the modulation and coding scheme (MCS) field in the DCI format 1 0 with CRC scrambled by RX- RNTI may be used to indicate the number the repetitions for Msg3 PDSCH transmission.

[0125] Example 14: The method of example 1, wherein an association between the number of repetitions for PRACH or Msg3 PUSCH transmissions and the number of repetitions for Msg4 PUSCH transmissions may be defined.

[0126] Example 15: The method of example 1, wherein for PDSCH transmission that is scheduled by DCI format 1 0 with CRC scrambled by C- RNTI, one field in the DCI format 1 0 may be explicitly included or repurposed to indicate the number of repetitions for the PDSCH transmissions.

[0127] Example 16: The method of example 1, wherein UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition only if certain condition is met.

[0128] Example 17: The method of example 1, wherein UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if RSRP (Reference Signal Received Power) measured at the UE is lower than RSRP threshold.

[0129] Example 18: The method of example 1, wherein UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if RSRQ (Reference Signal Received Quality) measured at the UE is lower than RSRQ threshold.

[0130] Example 19: The method of example 1, wherein UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition if SINR (Signal-to-Noise-Ratio) measured at the UE is lower than SINR threshold.

[0131] Example 20: The method of example 1, wherein UE transmits request for Msg2 PDSCH, MsgB PDSCH and / or Msg4 PDSCH repetition ifhypothetical PDSCH BLER (Block Error Rate) measured at the UE is higher than BLER threshold.

[0132] The Abstract is provided to comply with 37 C.F.R. Section 1.72(b) requiring an abstract that will allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMSWhat is claimed is:

1. An apparatus for a user equipment (UE) configured for operation in a fifth-generate new radio (5GNR) network, the apparatus comprising: processing circuitry; and memory, wherein to perform a four-step random-access (4-step RACH) procedure for initial access, the processing circuitry is configured to: encode a message three (Msg3) physical uplink shared channel (PUSCH) transmission to a gNodeB (gNB); decode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission; decode repetitions of the Msg4 PDSCH transmission received from a gNB in accordance with the scheduling, wherein the repetitions of the Msg4 PDSCH transmission are at least one of: configured to the UE via higher layer signalling; and signaled to the UE via a field of the DCI format.

2. The apparatus of claim 1, wherein when a number of the repetitions of the Msg4 PDSCH is signaled to the UE via the field in the DCI format, the DCI format is a DCI format 1 0 with Cyclic Redundancy Check (CRC) scrambled with a Temporary Cell Radio Network Temporary Identifier (TC-RNTI), and wherein when the number of the repetitions of the Msg4 PDSCH is configured via the higher layer signalling, the higher layer signalling indicates a set of numbers of repetitions and the field in the DCI format indicates the number of repetitions for the Msg4 PDSCH from the set.

3. The apparatus of claim 2 wherein when the field in the DCI format that indicates the number of repetitions for the Msg4 PDSCH is not present, the processing circuitry is configured to decode the Msg4 PDSCH transmission received from the gNB without repetitions.

4. The apparatus of claim 2, wherein the processing circuitry to configure the UE to transmit the Msg3 PUSCH transmission with repetitions to indicate that the UE supports repetition of the Msg4 PDSCH transmission.

5. The apparatus of claim 2, wherein the processing circuitry is configured to encode the Msg3 PUSCH transmission with a Medium Access Control - Control Element (MAC-CE) that indicates that the UE supports repetition of the Msg4 PDSCH transmission during the 4-step RACH procedure performed for initial access.

6. The apparatus of claim 2, wherein the UE is configured to encode a UE capability information element (IE) for transmission to the gNB that indicates that the UE supports repetition of the Msg4 PDSCH transmission during the 4-step RACH procedure performed for initial access.

7. The apparatus of claim 2, wherein the UE is configured to encode a request for repetition of the Msg4 PDSCH transmission for transmission to the gNB during the 4-step RACH procedure when a signal quality condition determined at the UE is below a threshold, the request for repetition of the Msg4 PDSCH transmission being indicated in the Msg3 PUSCH transmission.

8. The apparatus of claim 2, wherein as part of the 4-step RACH procedure, the processing circuitry is further configured to: encode a message one (Msgl) physical random-access channel (PRACH) transmission to the gNB for initial access, the Msgl PRACH transmission comprising one or more PRACH preambles transmitted in one or more PRACH occasions (ROs); and decode a message two (Msg2) PDSCH random access response (RAR) transmission received from the gNB, the Msg2 PDSCH including timing advance (TA) information, wherein the Msgl PRACH transmission is configured to indicate whether the UE supports repetition of at least one of:repetition of the Msg2 PDSCH transmission during the 4-step RACH procedure performed for initial access; and repetition of the Msg4 PDSCH transmission during the 4-step RACH procedure performed for initial access.

9. The apparatus of claim 8 wherein to indicate that the UE does not support repetitions of the Msg2 PDSCH, the processing circuitry is to configure the UE to transmit the Msgl PRACH transmission using PRACH resources that are configured to the UE, and wherein to indicate that the UE supports repetitions of the Msg2 PDSCH, the processing circuitry is to configure the UE to transmit the Msgl PRACH transmission using separate PRACH preambles for shared PRACH occasions (RO) or transmit the Msgl PRACH transmission using separate ROs that are different from the configured PRACH resources.

10. The apparatus of claim 2, wherein for communicating with the gNB via a non-terrestrial network (NTN), the DCI format and the Msg4 PDSCH transmission are received from the gNB via the NTN, wherein when the UE is communicating with the gNB via the NTN, the Msg4 PDSCH transmission is transmitted with repetitions for coverage enhancement, and wherein when the UE is communicating with the gNB via a terrestrial network, the Msg4 PDSCH transmission is transmitted without repetitions.

11. The apparatus of claim 10, wherein the NTN comprises at least one of a satellite and a high-altitude platform station configured to provide communications between the UE and the gNB.

12. A non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a user equipment (UE) configured for operation in a fifth-generate new radio (5G NR) network, wherein to perform a four-step random-access (4-step RACH) procedure for initial access, the processing circuitry is configured to:encode a message three (Msg3) physical uplink shared channel (PUSCH) transmission to a gNodeB (gNB); decode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission; decode repetitions of the Msg4 PDSCH transmission received from a gNB in accordance with the scheduling, wherein the repetitions of the Msg4 PDSCH transmission are at least one of: configured to the UE via higher layer signalling; and signaled to the UE via a field of the DCI format.

13. The non-transitory computer-readable storage medium of claim 12, wherein when a number of the repetitions of the Msg4 PDSCH is signaled to the UE via the field in the DCI format, the DCI format is a DCI format 1 0 with Cyclic Redundancy Check (CRC) scrambled with a Temporary Cell Radio Network Temporary Identifier (TC-RNTI), and wherein when the number of the repetitions of the Msg4 PDSCH is configured via the higher layer signalling, the higher layer signalling indicates a set of numbers of repetitions and the field in the DCI format indicates the number of repetitions for the Msg4 PDSCH from the set.

14. The non-transitory computer-readable storage medium of claim 13, wherein the processing circuitry to configure the UE to transmit the Msg3 PUSCH transmission with repetitions to indicate that the UE supports repetition of the Msg4 PDSCH transmission.

15. The non-transitory computer-readable storage medium of claim 13, wherein the UE is configured to encode a request for repetition of the Msg4 PDSCH transmission for transmission to the gNB during the 4-step RACH procedure when a signal quality condition determined at the UE is below a threshold, the request for repetition of the Msg4 PDSCH transmission being indicated in the Msg3 PUSCH transmission.

16. The non-transitory computer-readable storage medium of claim 13, wherein as part of the 4-step RACH procedure, the processing circuitry is further configured to: encode a message one (Msgl) physical random-access channel (PRACH) transmission to the gNB for initial access, the Msgl PRACH transmission comprising one or more PRACH preambles transmitted in one or more PRACH occasions (ROs); and decode a message two (Msg2) PDSCH random access response (RAR) transmission received from the gNB, the Msg2 PDSCH including timing advance (TA) information, wherein the Msgl PRACH transmission is configured to indicate whether the UE supports repetition of at least one of: repetition of the Msg2 PDSCH transmission during the 4-step RACH procedure performed for initial access; and repetition of the Msg4 PDSCH transmission during the 4-step RACH procedure performed for initial access.

17. The non-transitory computer-readable storage medium of claim 13, wherein for communicating with the gNB via a non-terrestrial network (NTN), the DCI format and the Msg4 PDSCH transmission are received from the gNB via the NTN, wherein when the UE is communicating with the gNB via the NTN, the Msg4 PDSCH transmission is transmitted with repetitions for coverage enhancement, and wherein when the UE is communicating with the gNB via a terrestrial network, the Msg4 PDSCH transmission is transmitted without repetitions.

18. An apparatus for gNodeB (gNB) configured for operation in a fifth- generate new radio (5G NR) network, the apparatus comprising: processing circuitry; and memory, wherein to perform a four-step random-access (4-step RACH) procedure with a user equipment (UE) for initial access, the processing circuitry is configured to:decode a message three (Msg3) physical uplink shared channel (PUSCH) transmission from the UE; encode a downlink control information (DCI) format scheduling a message 4 (Msg4) physical downlink shared channel (PDSCH) transmission; encode repetitions of the Msg4 PDSCH transmission for transmission to the UE in accordance with the scheduling, wherein the repetitions of the Msg4 PDSCH transmission are at least one of: configured to the UE via higher layer signalling; and signaled to the UE via a field of the DCI format.

19. The apparatus of claim 18, wherein when a number of the repetitions of the Msg4 PDSCH is signaled to the UE via the field in the DCI format, the DCI format is a DCI format 1 0 with Cyclic Redundancy Check (CRC) scrambled with a Temporary Cell Radio Network Temporary Identifier (TC- RNTI), and wherein when the number of the repetitions of the Msg4 PDSCH is configured via the higher layer signalling, the higher layer signalling indicates a set of numbers of repetitions and the field in the DCI format indicates the number of repetitions for the Msg4 PDSCH from the set.

20. The apparatus of claim 19, wherein when the UE is communicating with the gNB via a non-terrestrial network (NTN), the Msg4 PDSCH transmission is transmitted with repetitions for coverage enhancement, and wherein when the UE is communicating with the gNB via a terrestrial network, the Msg4 PDSCH transmission is transmitted without repetitions.

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