Enhanced phase tracking reference signal based on chirp sequences

Abstract

A method for transmitting a phase tracking reference signal (PT-RS) signal includes receiving, by a user equipment (UE) from a base station (BS) one or more messages including uplink PT-RS configuration parameters, and transmitting, by the UE to the BS, the PT-RS signal over radio resources of a physical uplink shared channel (PUSCH). The transmission is based on the uplink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, where the PT-RS sequence is based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PUSCH.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 63 / 161,513, filed on March 16, 2021 (the "Provisional Application"), the contents of which are incorporated herein by reference. [Background technology]

[0002] The present invention is directed to 5G, the fifth generation mobile network. It is the new global wireless standard after 1G, 2G, 3G, and 4G networks. 5G enables networks designed to connect machines, objects, and devices.

[0003] The present invention provides various capabilities to address phase tracking errors in 5G wireless networks, such as small frequency mismatches that can result in delays between transmitter and receiver signals. In some instances, phase differences may occur because the clocks of remote devices are not perfectly aligned. Even small differences in frequency can translate into phase offsets, which can lead to high bit error rates. In the system of the present invention, the receiver can implement a process to combat phase differences, for example, by utilizing chirp signals to enhance phase tracking reference signal (PT-RS) signal generation in downlink, uplink, and sidelink communications, and enhance phase tracking performance in user equipment (UE) or base station. Summary of the Invention

[0004] In one embodiment, the present invention provides a method for transmitting a phase tracking reference signal (PT-RS), the method including the steps of: receiving, by a user equipment (UE), one or more messages from a base station (BS) including uplink PT-RS configuration parameters; and transmitting, by the UE, a PT-RS signal to the BS via radio resources of a physical uplink shared channel (PUSCH), based on the uplink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, the PT-RS sequence being based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PUSCH. The uplink phase tracking reference signal (PT-RS) configuration parameter may be a first parameter that defines a chirp factor, and the chirp factor may be a predetermined value.

[0005] The method may further include receiving downlink control information (DCI) including a field having a value defining a chirp coefficient and / or receiving a medium access control (MAC) control element (CE) defining the chirp coefficient. Additionally, the one or more received messages may include a phase tracking reference signal (PT-RS) uplink configuration information element defining uplink PT-RS configuration parameters.

[0006] The uplink phase tracking reference signal (PT-RS) configuration parameters may embody a frequency density parameter defining the presence and frequency density of PT-RS as a function of a scheduled bandwidth of a physical uplink shared channel (PUSCH), may embody a parameter defining a maximum number of uplink PT-RS ports, and may embody a parameter indicating an uplink PT-RS boost factor per PT-RS port. In one embodiment, the method further includes implementing a resource element offset parameter that defines a subcarrier offset for the uplink PT-RS, and implementing a sample density parameter that defines a sample density for the PT-RS for a discrete frequency transform (DFT) spread orthogonal frequency division multiplexing (OFDM), pre-DFT, that defines a set of thresholds indicating a dependency between the presence of the PT-RS and the scheduled bandwidth of the physical uplink shared channel (PUSCH).

[0007] The uplink phase tracking reference signal (PT-RS) configuration parameters may embody a time density parameter that defines the presence and time density of the PT-RS as a function of the modulation and coding scheme (MCS), may embody a time density transform precoding parameter that defines the time density of the PT-RS for discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) at the OFDM symbol level, and may embody one or more parameters that define whether the uplink PT-RS is configured with a cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) waveform. The phase tracking reference signal (PT-RS) signal may be used for compensation of oscillator phase noise. The radio resources of the physical uplink shared channel (PUSCH) may be associated with cells in frequency range 2 (FR2).

[0008] A method for transmitting a phase tracking reference signal (PT-RS) signal can include receiving downlink control information (DCI) including an uplink grant defining radio resources of a physical uplink shared channel (PUSCH) for transmission of an uplink transport block. In one form, the downlink control information (DCI) is one of DCI format 0_0, DCI format 0_1, and DCI format 0_2. In one form,A first density of the PT-RS signals in the frequency domain is sparser than a second density of the PTR-RS signals in the time domain. In that regard, in the present invention, a phase tracking reference signal (PT-RS) sequence generation process includes the steps of generating a PT-RS sequence based on a first process when transform precoding is not enabled and based on a second process when transform precoding is enabled, and / or generating values ​​of the PT-RS sequence for different subcarriers to which the PT-RS sequence is mapped, and / or mapping the generated PT-RS sequence to different resource elements in radio resources of a physical uplink shared channel (PUSCH).

[0009] In one embodiment, the present invention provides a method for signal reception of a phase tracking reference signal (PT-RS), the method comprising the steps of: receiving, by a user equipment (UE), one or more messages including downlink PT-RS configuration parameters from a base station (BS); receiving, by the UE, a PT-RS signal from the BS over radio resources of a physical downlink shared channel (PDSCH), based on the downlink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, the PT-RS sequence being based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PDSCH. The downlink phase tracking reference signal (PT-RS) configuration parameters include a first parameter defining a chirp factor, the chirp factor being preferably a predetermined value.

[0010] The method may include receiving Downlink Control Information (DCI) including a field having a value defining a chirp factor, and / or receiving a Medium Access Control (MAC) Control Element (CE) defining the chirp factor. The number of messages may include a Phase Tracking Reference Signal (PT-RS) PT-RS Downlink Configuration information element that indicates PT-RS configuration parameters.

[0011] The downlink phase tracking reference signal (PT-RS) configuration parameters may embody an energy per resource element (EPRE) ratio parameter defining an EPRE ratio between the PT-RS and the physical downlink shared channel (PDSCH), may embody a frequency density parameter defining the presence and frequency density of the PT-RS as a function of the scheduled bandwidth of the physical downlink shared channel (PDSCH), may embody a parameter indicating a maximum number of downlink PT-RS ports, may embody a resource element offset parameter indicating a subcarrier offset of the downlink PT-RS, and may embody a time density parameter defining the presence and time density of the downlink PT-RS as a function of the MCS.

[0012] The method may include compensating oscillator phase noise based on a received phase tracking reference signal (PT-RS) signal. Preferably, the radio resource of the physical downlink shared channel (PDSCH) is associated with a cell in frequency range 2 (FR2). The method may also include performing at least one of time and frequency tracking, delay spread estimation, and Doppler spread estimation based on the received phase tracking reference signal (PT-RS) signal, or may include receiving downlink control information (DCI) including a downlink assignment defining the radio resource of the physical downlink shared channel (PDSCH) for reception of the downlink transport block.

[0013] Preferably, the downlink control information (DCI) is one of DCI format 1_0, DCI format 1_1, and DCI format 1_2. The first density of the PT-RS signal in the frequency domain is preferably sparser than the second density of the PTR-RS signal in the time domain. The phase tracking reference signal (PT-RS) sequence generation process includes generating values ​​of the PT-RS sequence for different subcarriers to which the PT-RS sequence is mapped. The phase tracking reference signal (PT-RS) mapping process includes mapping the generated PT-RS sequence to different resource elements in the radio resources of the physical downlink shared channel (PDSCH).

[0014] In one embodiment, the present invention provides a method for transmitting a phase tracking reference signal (PT-RS), the method comprising the steps of: receiving, by a first user equipment (UE), one or more messages from a base station including sidelink PT-RS configuration parameters; and transmitting, by the first UE, a PT-RS signal via radio resources of a physical sidelink shared channel (PSSCH) to a second UE based on the sidelink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, the PT-RS sequence being based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PSSCH. The sidelink phase tracking reference signal (PT-RS) configuration parameters include a first parameter defining a chirp factor, the chirp factor being a predetermined value.

[0015] The method may include receiving downlink control information including a field having a value defining a chirp coefficient and / or receiving a Medium Access Control (MAC) Control Element (CE) indicating the chirp coefficient. In that regard, the one or more messages may embody a Phase Tracking Reference Signal (PT-RS) sidelink configuration information element that defines sidelink PT-RS configuration parameters. The sidelink phase tracking reference signal (PT-RS) configuration parameter may embody a frequency density parameter that defines the presence and frequency density of PT-RS as a function of the scheduled bandwidth of the physical sidelink shared channel (PSSCH), may embody a resource element offset parameter that indicates a subcarrier offset of the sidelink PT-RS, and / or may embody a time density parameter that defines the presence and time density of sidelink PT-RS as a function of MCS.

[0016] The phase tracking reference signal (PT-RS) signal may be used to compensate for oscillator phase noise by a second user equipment (UE). The phase tracking reference signal (PT-RS) signal may be used for at least one of time and frequency tracking, delay spread estimation, and Doppler spread estimation.

[0017] The method may further include receiving downlink control information (DCI) including sidelink scheduling parameters indicating radio resources of a physical downlink shared channel (PSSCH) for transmission of the sidelink transport block. The downlink control information (DCI) is one of DCI format 3_0 and DCI format 3_1. A first density of the PT-RS signals in the frequency domain is sparser than a second density of the PTR-RS signals in the time domain. The phase tracking reference signal (PT-RS) sequence generation process may include generating values ​​of the PT-RS sequence for different subcarriers to which the PT-RS sequence is mapped, and the phase tracking reference signal (PT-RS) mapping process may include mapping the generated PT-RS sequence to different resource elements in the radio resources of the physical sidelink shared channel (PSSCH). [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 illustrates an example of a mobile communication system in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 2A] FIG. 2 illustrates an example of a radio protocol stack for the user plane and the control plane, in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 2B] FIG. 2 illustrates an example of a radio protocol stack for the user plane and the control plane, in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 3A] FIG. 1 illustrates an example mapping between logical channels and transport channels in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 3B] FIG. 1 illustrates an example mapping between logical channels and transport channels in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 3C] FIG. 1 illustrates an example mapping between logical channels and transport channels in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 4A] FIG. 2 illustrates an example mapping between transport channels and physical channels in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 4B] FIG. 2 illustrates an example mapping between transport channels and physical channels in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 4C] FIG. 2 illustrates an example mapping between transport channels and physical channels in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 5A] FIG. 1 illustrates an example of a radio protocol stack for NR sidelink communications in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 5B] FIG. 1 illustrates an example of a radio protocol stack for NR sidelink communications in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 5C] FIG. 1 illustrates an example of a radio protocol stack for NR sidelink communications in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 5D] FIG. 1 illustrates an example of a radio protocol stack for NR sidelink communications in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 6] FIG. 1 illustrates exemplary physical signals in the downlink, uplink, and sidelink in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 7]FIG. 2 illustrates an example of Radio Resource Control (RRC) states and transitions between different RRC states in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 8] FIG. 2 illustrates an example frame structure and physical resources in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 9] FIG. 1 illustrates example component carrier configurations in different carrier aggregation scenarios in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 10] FIG. 2 illustrates exemplary bandwidth portion configurations and switching in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 11] FIG. 1 illustrates an exemplary four-step contention-based and contention-free random access process in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 12] FIG. 1 illustrates an exemplary two-step contention-based and contention-free random access process, in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 13] A diagram illustrating an example time and frequency structure of a synchronization signal and a Physical Broadcast Channel (PBCH) block (SSB) in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 14] FIG. 2 illustrates an exemplary SSB burst transmission in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 15] FIG. 1 illustrates example components of a user equipment and a base station for transmission and / or reception in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 16] FIG. 2 illustrates an example phase tracking reference signal structure in the time domain in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 17] FIG. 1 illustrates an exemplary phase tracking reference signal (PT-RS) structure in the frequency domain in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 18] FIG. 1 illustrates an example chirp signal having a time-varying frequency in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 19] A diagram illustrating an example uplink PT-RS transmission process in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 20] A diagram illustrating an example downlink PT-RS reception process in accordance with certain aspects of various exemplary embodiments of the present disclosure. [Figure 21] FIG. 1 illustrates an example sidelink PT-RS transmission process, in accordance with certain aspects of various exemplary embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] FIG. 1 illustrates an example of a mobile communication system 100 according to some aspects of various exemplary embodiments of the present disclosure. The mobile communication system 100 may be operated by a wireless communication system operator, such as a Mobile Network Operator (MNO), a private network operator, a Multi-System Operator (MSO), an Internet of Things (IoT) network operator, etc., and may include voice, data (e.g., wireless internet), and the like. The network may provide services such as mobile internet access, messaging, vehicle communication services such as vehicle-to-vehicle, vehicle-to-infrastructure, and vehicle-to-everything (V2X) communication services, safety services, mission-critical services, and services in residential, commercial, or industrial environments such as IoT and Industrial IoT (IIOT).

[0020] The mobile communication system 100 can enable various types of applications with different requirements in terms of latency, reliability, throughput, etc. Examples of supported applications include enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), and massive machine type communications (mMTC). eMBB can support stable connections with high peak data rates and moderate rates for cell edge users. URLLC can support applications with stringent requirements in terms of latency and reliability, as well as moderate requirements in terms of data rates. An exemplary mMTC application includes a network of a large number of IoT devices that are only sporadically active and transmit small data payloads.

[0021] The mobile communication system 100 may include a radio access network (RAN) portion and a core network portion. In the example shown in FIG. 1, a Next Generation RAN (NG-RAN) 105 and a 5G Core Network (5GC) 110 are shown as examples of a RAN and a core network, respectively. Other examples of a RAN and a core network may be implemented without departing from the scope of the present disclosure. Other examples of a RAN include an Evolved Universal Terrestrial Radio Access Network (EUTRAN), a Universal Terrestrial Radio Access Network (UTRAN), and the like. Other examples of a core network include an Evolved Packet Core (EPC), a UMTS Core Network (UCN), and the like. The RAN implements a radio access technology (RAT) and resides between a user equipment (UE) 125 and the core network. Examples of such RATs include New Radio (NR), Long Term Evolution (LTE), also known as Evolved Universal Terrestrial Radio Access (EUTRA), Universal Mobile Telecommunications System (UMTS), and the like. The RAT of the example mobile communication system 100 may be NR. The core network exists between the RAN and one or more external networks (e.g., data networks) and is responsible for functions such as mobility management, authentication, session management, bearer setup, and application of different Quality of Service (QoS). The functional layer between the UE 125 and the RAN (e.g., NG-RAN 105) may be referred to as the Access Stratum (AS), and the functional layer between the UE 125 and the core network (e.g., 5GC 110) may be referred to as the Non-access Stratum (NAS).

[0022] The UE 125 may include wireless transmission and reception means for communicating with one or more nodes in a RAN, one or more relay nodes, or one or more other UEs, etc. Examples of UEs include, but are not limited to, smartphones, tablets, laptops, computers, wireless transmitting and / or receiving units in vehicles, V2X or vehicle-to-vehicle (V2V) devices, wireless sensors, IoT devices, IIOT devices, etc. Other names may be used for UEs, such as mobile station (MS), terminal equipment, terminal node, client device, mobile device, etc.

[0023] The RAN may include nodes (e.g., base stations) for communicating with UEs. For example, the NG-RAN 105 of the mobile communication system 100 may include nodes for communicating with the UE 125. Different names may be used for the RAN nodes depending, for example, on the RAT used for the RAN. In a RAN using a UMTS RAT, a RAN node may be referred to as a Node B (NB). In a RAN using a LTE / EUTRA RAT, a RAN node may be referred to as an evolved Node B (eNB). In the mobile communication system of FIG. In an exemplary example of the system 100, the nodes of the NG-RAN 105 may be either a Next Generation Node B (gNB) 115 or a Next Generation Evolved Node B (ng-eNB) 120. In this specification, the terms base station, RAN node, gNB, and ng-eNB may be used interchangeably. The gNB 115 may provide NR user plane and control plane protocol terminations to the UE 125. The ng-eNB 120 may provide E-UTRA user plane and control plane protocol terminations towards the UE 125. The interface between the gNB 115 and the UE 125 or between the ng-eNB 120 and the UE 125 may be referred to as a Uu interface. The Uu interface may be established using a user plane protocol stack and a control plane protocol stack. For the Uu interface, the direction from the base station (e.g., gNB 115 or ng-eNB 120) to the UE 125 may be referred to as the downlink, and the direction from the UE 125 to the base station (e.g., gNB 115 or ng-eNB 120) may be referred to as the uplink.

[0024] The gNB 115 and the ng-eNB 120 may be interconnected using an Xn interface. The Xn interface may include an Xn User Plane (Xn-U) interface and an Xn Control Plane (Xn-C) interface. The transport network layer of the Xn-U interface may be built on Internet Protocol (IP) transport, and GPRS Tunneling Protocol (GTP) may be used on User Datagram Protocol (UDP) / IP to carry user plane protocol data units (PDUs). Xn-U may provide non-guaranteed delivery of user plane PDUs and may support data forwarding and flow control. The transport network layer of the Xn-C interface may be built on Stream Control Transport Protocol (SCTP) on IP. The application layer signaling protocol may be referred to as Xn Application Protocol (XnAP). The SCTP layer may provide guaranteed delivery of application layer messages. At the transport IP layer, point-to-point transmission may be used to deliver the signaling PDUs. The Xn-C interface can support Xn interface management, UE mobility management including context transfer and RAN paging, and dual connectivity.

[0025] The gNB 115 and ng-eNB 120 may also be connected to the 5GC 110 by an NG interface, more specifically to the Access and Mobility Management Function (AMF) 130 of the 5GC 110 by an NG-C interface, and to the User Plane Function (UPF) 135 of the 5GC 110 by an NG-U interface. The transport network layer of the NG-U interface may be built on IP transport and may carry user plane PDUs between the NG-RAN nodes (e.g., gNB 115 or ng-eNB 120) and the UPF 135 using the GTP protocol over UDP / IP. The NG-U may provide non-guaranteed delivery of user plane PDUs between the NG-RAN nodes and the UPF. The transport network layer of the NG-C interface may be built on IP transport. SCTP may be added on top of IP for reliable transmission of signaling messages. Applications The layer signaling protocol may be referred to as NG Application Protocol (NGAP). The SCTP layer can provide guaranteed delivery of application layer messages. IP Layer In the NG-C interface, IP layer point-to-point transmission may be used to deliver signaling PDUs. The NG-C interface may provide the following functions: NG interface management, UE context management, UE mobility management, forwarding of NAS messages, paging, PDU session management, configuration forwarding, and alert message transmission.

[0026] The gNB 115 or ng-eNB 120 provides the following functions: radio bearer control, radio admission control, connection mobility control, radio resource management functions such as dynamic allocation of resources (e.g., scheduling) to UEs in both uplink and downlink, IP and Ethernet header compression, encryption and integrity protection of data, selection of the AMF at the UE attachment when routing to the AMF cannot be determined from information provided by the UE, routing of user plane data to the UPF, routing of control plane information to the AMF, connection setup and release, scheduling and transmission of paging messages, system broadcasting. The 5G LTE-R2 may host one or more of the following: scheduling and transmission of traffic information (e.g., derived from the AMF), measurement and measurement reporting configuration for mobility and scheduling, transport level packet marking in the uplink, session management, support for network slicing, QoS flow management and mapping to data radio bearers, support for UEs in RRC inactive state, delivery functionality for NAS messages, radio access network sharing, dual connectivity, close interaction between NR and E-UTRA, and maintaining security and radio configuration for User Plane 5G System (5GS) Cellular IoT (CIoT) optimization.

[0027] The AMF130 may host one or more of the following functions: NAS signaling termination, NAS signaling security, AS security control, CN inter-node signaling for mobility between 3GPP access networks, idle mode UE reachability (including control and execution of paging retransmissions), registration area management, support for intra-system and inter-system mobility, access authentication, access authorization including validation of roaming rights, mobility management control (subscription and policy), support for network slicing, Session Management Function (SMF) selection, and 5GS CIoT optimization selection.

[0028] The UPF 135 may host one or more of the following functions: anchor point for intra / inter-RAT mobility (if applicable), external PDU session point of interconnection to data network, packet routing and forwarding, packet inspection and user plane part of policy rule enforcement, traffic usage reporting, uplink classifier supporting routing of traffic flows to data network, branching point to support multi-homed PDU sessions, QoS processing for user plane, e.g., packet filtering, gating, UL / DL rate enforcement, uplink traffic validation (Service Data Flow (SDF) to QoS flow mapping), and downlink packet buffering and downlink data notification triggering.

[0029] As shown in FIG. 1, the NG-RAN 105 may support a PC5 interface between two UEs 125 (e.g., UE 125A and UE 125B). In the PC5 interface, the direction of communication between the two UEs (e.g., from UE 125A to UE 125B or vice versa) may be referred to as a sidelink. Sidelink transmission and reception over the PC5 interface may be supported when the UE 125 is within NG-RAN 105 coverage and when the UE is outside NG-RAN 105 coverage, regardless of which RRC state the UE 125 is in. Support for V2X services over the PC5 interface may be provided by NR sidelink communication and / or V2X sidelink communication.

[0030] PC5-S signaling can be used for unicast link establishment with direct communication request / accept messages. The UE can self-assign the source Layer-2 ID of the PC5 unicast link based on, for example, the V2X service type. During the PC5 unicast link establishment procedure, a UE may send its source Layer-2 ID for the PC5 unicast link to a peer UE, e.g., a UE from which the destination ID was received from higher layers. The source Layer-2 ID and destination Layer-2 ID pair may uniquely identify a unicast link. The receiving UE may verify that the destination ID belongs to it and may accept the unicast link establishment request from the source UE. During the PC5 unicast link establishment procedure, PC5-RRC procedures on the access stratum may be invoked for the purpose of UE sidelink context establishment, as well as for AS layer configuration, capability exchange, etc. PC5-RRC signaling may enable the exchange of UE capabilities and AS layer configurations such as Sidelink radio bearer configuration between a pair of UEs for which a PC5 unicast link is established.

[0031] NR sidelink communication may support one of three types of transmission modes (e.g., unicast transmission, groupcast transmission, and broadcast transmission) for a pair of source Layer 2 ID and destination Layer 2 ID in an AS. The unicast transmission mode may be characterized by the support of one PC5-RRC connection between peer UEs for the pair, the transmission and reception of control information and user traffic between peer UEs in the sidelink, the support of sidelink HARQ feedback, the support of sidelink transmit power control, the support of RLC acknowledged mode (AM), and the detection of radio link failure for the PC5-RRC connection. The groupcast transmission may be characterized by the transmission and reception of user traffic between UEs belonging to a group in the sidelink, and the support of sidelink HARQ feedback. The broadcast transmission may be characterized by the transmission and reception of user traffic between UEs in the sidelink.

[0032] For NR sidelink communications, a source Layer-2 ID, a destination Layer-2 ID, and a PC5 link identifier may be used. The source Layer-2 ID is the CallThe Destination Layer 2 ID may be a link layer identity that identifies the device or group of devices that is the destination of the sidelink communication frame. Reception The source Layer-2 ID may be a link layer identification that identifies the device that is to receive the data. In some examples, the source Layer-2 ID and the destination Layer-2 ID may be assigned by a management function in the core network. The source Layer-2 ID may identify the source of the data in the NR sidelink communication. The source Layer-2 ID may be 24 bits long and may be split into two bit strings at the MAC layer. One bit string may be the LSB portion (8 bits) of the source Layer-2 ID and may be forwarded to the sender's physical layer. This may identify the source of the intended data in the sidelink control information and may be used for packet filtering at the receiver's physical layer. The second bit string may be the MSB portion (16 bits) of the source Layer-2 ID and may be carried in a medium access control (MAC) header. This may be used for packet filtering at the receiver's MAC layer. The destination Layer-2 ID may identify the target of the data in the NR sidelink communication. For NR sidelink communication, the destination Layer-2 ID may be 24 bits long and may be split into two bit strings at the MAC layer. One bit string may be the LSB part (16 bits) of the destination Layer 2 ID and may be forwarded to the sender's physical layer. This may identify the intended target of the data in the sidelink control information and may be used for packet filtering at the receiver's physical layer. The second bit string may be the MSB part (8 bits) of the destination Layer 2 ID and may be carried in the MAC header. This may be used for packet filtering at the receiver's MAC layer. The PC5 link identifier may uniquely identify a PC5 unicast link in the UE for the lifetime of the PC5 unicast link. The PC5 link identifier may be used to indicate the PC5 unicast link for which a sidelink Radio Link Failure (RLF) declaration has been made and the PC5-RRC connection has been released.

[0033] 2A and 2B illustrate example radio protocol stacks for the user plane and control plane, respectively, according to some aspects of various exemplary embodiments of the present disclosure. As shown in FIG. 2A, the protocol stack for the user plane of the Uu interface (between the UE 125 and the gNB 115) includes Service Data Adaptation Protocol (SDAP) 201 and SDAP 211, Packet Data Convergence Protocol (PDCP) 202 and PDCP 212, Radio Link Control (RLC) 203 and RLC 213, MAC 204 and MAC 214, and sublayers of Layer 2 and Physical (PHY) 205 and PHY 215 layers (Layer 1 is also referred to as L1).

[0034] The PHY 205 and PHY 215 provide transport channels 244 to the MAC 204 and MAC 214 sublayers. The MAC 204 and MAC 214 sublayers provide logical channels 243 to the RLC 203 and RLC 213 sublayers. The RLC 203 and RLC 213 sublayers provide RLC channels 242 to the PDCP 202 and PCP 212 sublayers. The PDCP 202 and PDCP 212 sublayers provide radio bearers 241 to the SDAP 201 and SDAP 211 sublayers. The radio bearers may be classified into two groups: Data Radio Bearers (DRBs) for user plane data and Signaling Radio Bearers (SRBs) for control plane data. The SDAP 201 and SDAP 211 sublayers provide QoS flows 240 to the 5GC.

[0035] The main services and functions of the MAC204 or MAC214 sublayer are mapping between logical channels and transport channels, one or Multiple Multiplexing / demultiplexing of MAC Service Data Units (SDUs) belonging to different logical channels into / from Transport Blocks (TBs) passed to / from the physical layer on the transport channel, reporting of scheduling information, error correction with Hybrid Automatic Repeat Request (HARQ) (One HARQ entity per cell in case of Carrier Aggregation (CA)), priority handling between UEs with dynamic scheduling, priority handling between logical channels of one UE with Logical Channel Prioritization (LCP), priority handling between overlapping resources of one UE, and padding. A single MAC entity may support multiple numerologies, transmission timings, and cells. Mapping restrictions in logical channel prioritization control which numerologies, cells, and transmission timings a logical channel can use.

[0036] The HARQ function can ensure delivery between peer entities at Layer 1. If the physical layer is not configured for downlink / uplink spatial multiplexing, a single HARQ process can support one TB, and if the physical layer is configured for downlink / uplink spatial multiplexing, a single HARQ process can support one or multiple TBs.

[0037] The RLC 203 or RLC 213 sublayer can support three transmission modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC configuration may be per logical channel independent of the numerology and / or transmission time, and the Automatic Repeat Request (ARQ) may operate with any of the numerologies and / or transmission times for which the logical channel is configured.

[0038] The main services and functions of the RLC203 or RLC213 sublayer depend on the transmission mode (e.g. TM, UM or AM) and include: transport of upper layer PDUs, sequence numbers independent of the PDCP sequence numbers (UM and AM), error correction with ARQ (AM only), segmentation (AM and UM) and resegmentation (AM only), reassembly of SDUs (AM and UM), duplicate detection (AM only), and RLC SDUs. This may include discarding (AM and UM), RLC re-establishment, and protocol error detection (AM only).

[0039] An automatic repeat request in the RLC203 or RLC213 sublayer may have the following characteristics: ARQ retransmits an RLC SDU or an RLC SDU segment based on an RLC status report. Polling for an RLC status notification may be used if required by the RLC. The RLC receiver may also trigger an RLC status notification after detecting a missing RLC SDU or an RLC SDU segment.

[0040] The main services and functions of the PDCP202 or PDCP212 sublayer may include forwarding of data (user plane or control plane), maintenance of the PDCP sequence number (SN), header compression and decompression using the Robust Header Compression (ROHC) protocol, header compression and decompression using the EHC protocol, encryption and decryption, integrity protection and integrity verification, timer-based SDU discard, split bearer routing, duplication, reordering and in-order delivery, out-of-order delivery, and duplicate discarding.

[0041] The main services and functions of the SDAP 201 or SDAP 211 include mapping between QoS flows and data radio bearers, and marking QoS Flow IDs (QFIs) in both downlink and uplink packets. A single protocol entity of the SDAP may be configured for each individual PDU session.

[0042] As shown in FIG. 2B, the control plane protocol stack of the Uu interface (between UE 125 and gNB 115) includes the PHY layer (Layer 1), the MAC, RLC and PDCP sublayers of Layer 2, and further the RRC 206 and RRC 216 sublayers, as described above. The main services and functions of the RRC206 and RRC216 sublayers on the Uu interface include broadcasting of system information related to AS and NAS, paging initiated by 5GC or NG-RAN, establishment, maintenance and release of RRC connection between UE and NG-RAN (including adding, modifying and releasing carrier aggregation, and adding, modifying and releasing dual connectivity between NR or E-UTRA and NR), security functions including key management, establishment, configuration, maintenance and release of SRB and DRB, mobility functions (including handover and context transfer, UE cell selection and reselection and control of cell selection and reselection, and inter-RAT mobility), QoS management functions, control of UE measurement and reporting, detection and recovery of radio link failure, and forwarding of NAS messages between NAS and UE. The NAS207 and NAS227 layers are control protocols (terminated in the AMF on the network side) that perform functions such as authentication, mobility management, and security control.

[0043] Sidelink specific services and functions of the RRC sublayer over the Uu interface include configuration of sidelink resource allocation via system information or dedicated signaling, reporting of UE sidelink information, sidelink related measurement configuration and reporting, and reporting of UE assistance information for SL traffic patterns.

[0044] 3A, 3B, and 3C show example mappings between logical channels and transport channels in the downlink, uplink, and sidelink, respectively, according to some aspects of various exemplary embodiments of the present disclosure. Different types of data transfer services may be provided by the MAC. Each logical channel type may be defined by what type of information is transferred. The logical channels may be classified into two groups: control channels and traffic channels. The control channels are used for control play and traffic control. A UE may be used only for the transfer of user plane information. A Broadcast Control Channel (BCCH) is a downlink channel for broadcasting system control information. A Paging Control Channel (PCCH) is a downlink channel that carries paging messages. A Common Control Channel (CCCH) is a channel for transmitting control information between a UE and a network. This channel may be used for UEs that do not have an RRC connection with the network. A Dedicated Control Channel (DCCH) is a point-to-point bidirectional channel that transmits dedicated control information between a UE and a network and may be used by UEs that have an RRC connection. A Traffic Channel may be used only for the transfer of user plane information. A Dedicated Traffic Channel (DTCH) is a point-to-point channel dedicated to one UE for transferring user information. A DTCH can exist in both uplink and downlink. A Sidelink Control Channel (SCCH) is a sidelink channel for transmitting control information (e.g., PC5-RRC and PC5-S messages) from one UE to other UEs. A Sidelink Traffic Channel (STCH) is a sidelink channel for transmitting user information from one UE to other UEs. The Sidelink Broadcast Control Channel (SBCCH) is a sidelink channel for broadcasting sidelink system information from one UE to other UEs.

[0045] Downlink transport channel types include the Broadcast Channel (BCH), the Downlink Shared Channel (DL-SCH), and the Paging Channel (PCH). The BCH can feature a fixed, predefined transport format. It needs to be broadcast throughout the coverage area of ​​a cell, either as a single message or by beamforming different BCH instances. 。D The L-SCH may be characterized by support for HARQ, support for dynamic link adaptation by varying modulation, coding, and transmit power, the possibility of being broadcast throughout the cell, the possibility of using beamforming, support for both dynamic and semi-static resource allocation, and support for UE discontinuous reception (DRX) to enable UE power saving. The PCH may be characterized by support for UE discontinuous reception (DRX) to enable UE power saving (DRX cycles are indicated to the UE by the network), a requirement to be broadcast throughout the coverage area of ​​a cell, either as a single message or by beamforming different BCH instances, and mapped to physical resources that can also be dynamically used for traffic / other control channels.

[0046] In the downlink, the following connections may exist between logical channels and transport channels: BCCH may be mapped to BCH. BCCH may be mapped to DL-SCH. PCCH may be mapped to PCH. CCCH may be mapped to DL-SCH. DCCH may be mapped to DL-SCH. DTCH may be mapped to DL-SCH.

[0047] Uplink transport channel types include the Uplink Shared Channel (UL-SCH) and the Random Access Channel (RACH). The UL-SCH may be characterized by the possibility of using beamforming, support for dynamic link adaptation by varying transmit power and potentially modulation and coding, support for HARQ, and support for both dynamic and quasi-static resource allocation. The RACH may be characterized by limited control information and collision risk.

[0048] In the uplink, the following connections may exist between logical channels and transport channels: CCCH may be mapped to UL-SCH, DCCH may be mapped to UL-SCH, DTCH may be mapped to UL-SCH.

[0049] Sidelink transport channel types include Sidelink Broadcast Channel (SL-BCH) and Sidelink Shared Channel (SL-SCH). The SL-BCH may be characterized by a predefined transport format. The SL-SCH may be characterized by support for unicast, groupcast, and broadcast transmissions, support for both UE autonomous resource selection and scheduled resource allocation by the NG-RAN, support for both dynamic and semi-static resource allocation when the UE is assigned resources by the NG-RAN, support for HARQ, and support for dynamic link adaptation by varying transmit power, modulation, and coding.

[0050] In the sidelink, the following connections may exist between logical channels and transport channels: SCCH may be mapped to SL-SCH, STCH may be mapped to SL-SCH, and SBCCH may be mapped to SL-BCH.

[0051] 4A, 4B, and 4C illustrate example mappings between transport channels and physical channels in the downlink, uplink, and sidelink, respectively, according to some aspects of various exemplary embodiments of the present disclosure. The physical channels in the downlink include a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), and a physical broadcast channel (PBCH). The PCH and DL-SCH transport channels are mapped to the PDSCH. The BCH transport channel is mapped to the PBCH. No transport channels are mapped to the PDCCH, and downlink control information (DCI) is transmitted via the PDCCH.

[0052] The physical channels in the uplink include the Physical Uplink Shared Channel (PUSCH), the Physical Uplink Control Channel (PUCCH), and the Physical Random Access Channel (PRACH). The UL-SCH transport channel may be mapped to the PUSCH, and the RACH transport channel may be mapped to the PRACH. No transport channel is mapped to the PUCCH, and uplink control information (UCI) is transmitted via the PUCCH.

[0053] The sidelink physical channels include the physical sidelink shared channel (PSSCH), the physical sidelink control channel (PSCCH), the physical sidelink feedback channel (PSFCH), and the physical sidelink broadcast channel (PSBCH). The physical sidelink control channel (PSCCH) may indicate the resources and other transmission parameters used by the UE for the PSSCH. The physical sidelink shared channel (PSSCH) may transmit TBs of the data itself, as well as control information such as HARQ procedures and CSI feedback triggers. At least six OFDM symbols in a slot may be used for PSSCH transmission. The physical sidelink feedback channel (PSFCH) may carry HARQ feedback over the sidelink from the UE that is the intended recipient of the PSSCH transmission to the UE that performed the transmission. The PSFCH sequence may be transmitted in one PRB repeated across two OFDM symbols near the end of the sidelink resources in the slot. The SL-SCH transport channel may be mapped to the PSSCH. The SL-BCH may be mapped to the PSBCH. The transport channel is mapped to the PSFCH. The transport channels are not pinged to the PSFCH, but sidelink feedback control information (SFCI) may be mapped to the PSCCH. The transport channels are not mapped to the PSCCH, but sidelink control information (SCI) may be mapped to the PSCCH.

[0054] 5A, 5B, 5C, and 5D respectively illustrate examples of radio protocol stacks for NR sidelink communication according to some aspects of various exemplary embodiments of the present disclosure. The AS protocol stack for the user plane in the PC5 interface (i.e., for STCH) may consist of SDAP, PDCP, RLC and MAC sublayers, and a physical layer. The protocol stack of the user plane is shown in FIG. 5A. The AS protocol stack for the SBCCH in the PC5 interface may consist of RRC, RLC, MAC sublayers, and a physical layer, as shown below in FIG. 5B. To support the PC5-S protocol, PC5-S is placed above the PDCP, RLC, and MAC sublayers, and a physical layer in the control plane protocol stack for SCCH for PC5-S, as shown in FIG. 5C. The AS protocol stack for the control plane for SCCH for RRC in the PC5 interface consists of RRC, PDCP, RLC and MAC sublayers, and a physical layer. The protocol stack of the control plane for SCCH for RRC is shown in FIG. 5D.

[0055] Sidelink Radio Bearers (SLRBs) can be categorized into two groups: Sidelink Data Radio Bearers (SL DRBs) for user plane data and Sidelink Signalling Radio Bearers (SL SRBs) for control plane data. Separate SL SRBs using different SCCHs can be configured for PC5-RRC and PC5-S signalling, respectively.

[0056] The MAC sublayer can provide the following services and functions over the PC5 interface: radio resource selection, packet filtering, priority handling between uplink and sidelink transmissions for a given UE, and sidelink CSI reporting. Due to the restriction of logical channel prioritization in the MAC, only sidelink logical channels belonging to the same destination can be multiplexed into the MAC PDU for each unicast, groupcast, and broadcast transmission that may be associated with the destination. For packet filtering, a SL-SCH MAC header containing both source and destination Layer-2 ID parts may be added to the MAC PDU. The logical channel identifier (LCID) included within the MAC subheader can uniquely identify a logical channel within the combination of source Layer-2 ID and destination Layer-2 ID.

[0057] The services and functions of the RLC sublayer may be supported for the sidelink. Both RLC unacknowledged mode (UM) and acknowledged mode (AM) may be used for unicast transmission, while only UM may be used for groupcast or broadcast transmission. For UM, only one-way transmission may be supported for groupcast and broadcast.

[0058] The services and functions of the PDCP sublayer for the Uu interface may be supported for the sidelink with some restrictions: out-of-order delivery may only be supported for unicast transmission and may not support duplication over the PC5 interface.

[0059] The SDAP sublayer provides the following services and functions over the PC5 interface: mapping between QoS flows and sidelink data radio bearers: unicast, groupcast and broadcast associated destinations. There can be one SDAP entity per destination for one of the casts.

[0060] The RRC sublayer may provide the following services and functions over the PC5 interface: forwarding PC5-RRC messages between peer UEs, maintaining and releasing PC5-RRC connections between two UEs, and detecting sidelink radio link failures for PC5-RRC connections based on indications from MAC or RLC. A PC5-RRC connection may be a logical connection between two UEs for a pair of source Layer-2 ID and destination Layer-2 ID that may be considered established after a corresponding PC5 unicast link is established. There may be a one-to-one correspondence between PC5-RRC connections and PC5 unicast links. A UE may have multiple PC5-RRC connections with one or more UEs for different pairs of source Layer-2 ID and destination Layer-2 ID. Separate PC5-RRC procedures and messages may be used for a UE to forward UE capabilities and sidelink configurations, including SL-DRB configurations, to a peer UE. Both peer UEs may exchange their UE capabilities and sidelink configurations using separate bidirectional procedures in both sidelink directions.

[0061] FIG. 6 illustrates exemplary physical signals in the downlink, uplink, and sidelink according to some aspects of various exemplary embodiments of the present disclosure. Demodulation reference signals (DM-RS) may be used in the downlink, uplink, and sidelink and may be used for channel estimation. DM-RS is a UE-specific reference signal that may be transmitted with the downlink, uplink, or sidelink physical channel and may be used for channel estimation and coherent detection of the physical channel. Phase tracking reference signals (PT-RS) may be used in the downlink, uplink, and sidelink and may be used to track phase and mitigate performance loss due to phase noise. PT-RS may be primarily used to estimate and minimize the impact of common phase error (CPE) on system performance. Due to phase noise characteristics, PT-RS signals may have low density in the frequency domain and high density in the time domain. PT-RS may occur when PT-RS is configured to exist in combination with DM-RS. Positioning reference signals (PRS) may be used in the downlink for positioning with different positioning techniques. The PRS may be used to measure the delay of the downlink transmission by correlating the received signal from the base station with a local replica in the receiver. The Channel State Information Reference Signal (CSI-RS) may be used in the downlink and the sidelink. The CSI-RS may be used for channel state estimation, Reference Signal Received Power (RSRP) measurement for mobility and beam management, time / frequency tracking for demodulation, among others. The CSI-RS may be configured UE specific, but multiple users may share the same CSI-RS resource. The UE may determine the CSI reports and transmit these in the uplink to the base station using the PUCCH or PUSCH. The CSI reports may be carried in the sidelink MAC CE. The Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS) may be used for radio frame synchronization. The PSS and SSS may be used for cell search procedures during initial attach or for mobility purposes.A Sounding Reference Signal (SRS) may be used in the uplink for uplink channel estimation. Similar to CSI-RS, the SRS can serve as a QCL reference for other physical channels, such that it may be configured to be transmitted quasi-collocated with the SRS. Sidelink PSS (S-PSS) and Sidelink SSS (S-SSS) may be used in the sidelink for sidelink synchronization.

[0062] 7 illustrates examples of Radio Resource Control (RRC) states and transitions between different RRC states in accordance with certain aspects of various exemplary embodiments of the present disclosure. A UE can be in one of three RRC states: an RRC connected state 710, an RRC idle state 720, and an RRC inactive state 730. After powering on, the UE is in an RRC idle state 720. 0, and the UE may use initial access to establish a connection with the network via an RRC connection establishment procedure to perform data transfer and / or conduct voice calls. Once the RRC connection is established, the UE may be in an RRC connected state 710. The UE can transition from an RRC idle state 720 to an RRC connected state 710 or from an RRC connected state 710 to an RRC idle state 720 using an RRC connection establishment / release procedure 740.

[0063] The RRC inactive state 730 may be used to reduce signaling load and latency resulting from frequent transitions from the RRC connected state 710 to the RRC idle state 720 when the UE transmits frequent small data. In the RRC inactive state 730, the AS context may be stored by both the UE and the gNB. This may result in a faster state transition from the RRC inactive state 730 to the RRC connected state 710. The UE may transition from the RRC inactive state 730 to the RRC connected state 710 or from the RRC connected state 710 to the RRC inactive state 730 using an RRC connection resume / deactivation procedure 760. The UE may transition from the RRC inactive state 730 to the RRC idle state 720 using an RRC connection release procedure 750.

[0064] FIG. 8 illustrates an example frame structure and physical resources according to some aspects of various example embodiments of the present disclosure. Downlink or uplink or sidelink transmissions may be organized into frames with a duration of 10 ms consisting of ten 1 ms subframes. Each subframe may consist of 1, 2, 4, ... slots, and the number of slots per subframe may depend on the subcarrier spacing of the carrier on which the transmission takes place. The slot duration may be 14 symbols with a normal cyclic prefix (CP) and 12 symbols with an extended CP. And may be scaled in time depending on the subcarrier spacing used so that there is an integer number of slots in a subframe. FIG. 8 illustrates a resource grid in the time and frequency domain. Each element of the resource grid containing one symbol in time and one subcarrier in frequency is called a resource element (RE). A resource block (RB) may be defined as 12 consecutive subcarriers in the frequency domain.

[0065] In some examples, with non-slot-based scheduling, the transmission of a packet may occur over a portion of a slot, e.g., during 2, 4, or 7 OFDM symbols, which may also be referred to as a minislot. Minislots may be used for low-latency applications such as URLLC and operation in unlicensed bands. In some embodiments, minislots may also be used for fast flexible scheduling of services (e.g., preemption of URLLC for eMBB).

[0066] FIG. 9 illustrates examples of component carrier configurations in different carrier aggregation scenarios according to some aspects of various exemplary embodiments of the present disclosure. In carrier aggregation (CA), two or more component carriers (CCs) may be aggregated. A UE may receive or transmit simultaneously on one or more CCs depending on its capabilities. CA may be supported for both contiguous and non-contiguous CCs in the same band or different bands as illustrated in FIG. 9. The gNB and the UE may communicate using a serving cell. The serving cell may be associated with at least one downlink CC (e.g., may be associated with only one downlink CC or may be associated with a downlink CC and an uplink CC). The serving cell may be a primary cell (PCell) or a secondary cCell (SCell).

[0067] The UE can use the uplink timing control procedure to adjust the timing of its uplink transmissions. The gNB can adjust the uplink frame timing relative to the frame timing. The gNB can determine a desired timing advance setting and provide it to the UE. The UE can use the provided TA to determine its uplink transmit timing relative to the UE's observed downlink receive timing.

[0068] In the RRC connected state, the gNB may be responsible for maintaining the timing advance to keep L1 synchronized. Serving cells with uplinks to which the same timing advance applies and using the same timing reference cell are grouped into a Timing Advance Group (TAG). A TAG may contain at least one serving cell with a configured uplink. The mapping of serving cells to TAGs may be configured by RRC. For a primary TAG, the UE may use the PCell as the timing reference cell, except for shared spectrum channel access where the SCell may also be used as the timing reference cell in some cases. For a secondary TAG, the UE may use any of the activated SCells of this TAG as the timing reference cell and may not change this unless necessary.

[0069] Timing advance updates may be signaled by the gNB to the UE via a MAC CE command. Such a command may restart a TAG-specific timer that may indicate whether L1 may be synchronized or not; when the timer is running, L1 may be considered synchronized, otherwise L1 may be considered unsynchronized (uplink transmissions may only occur on the PRACH in this case).

[0070] A UE with single timing advance capability for CA may simultaneously receive and / or transmit multiple CCs corresponding to multiple serving cells (multiple serving cells grouped into one TAG) sharing the same timing advance. A UE with multiple timing advance capability for CA may simultaneously receive and / or transmit multiple CCs corresponding to multiple serving cells (multiple serving cells grouped into multiple TAGs) with different timing advances. NG-RAN may ensure that each TAG contains at least one serving cell. A non-CA capable UE may receive on a single CC and transmit on a single CC corresponding to only one serving cell (one serving cell in one TAG).

[0071] The multi-carrier property of the physical layer in case of CA may be exposed to the MAC layer, and one HARQ entity may be required per serving cell. If CA is configured, the UE may have one RRC connection with the network. In RRC connection establishment / re-establishment / handover, one serving cell (e.g., PCell) may provide NAS mobility information. Depending on the UE capabilities, the SCell may be configured to form a set of serving cells together with the PCell. The set of serving cells configured for the UE may consist of one PCell and one or multiple SCells. Reconfiguration, addition, and removal of SCells may be performed by RRC.

[0072] In a dual connectivity scenario, a UE may be configured with multiple cells including a Master Cell Group (MCG) for communicating with a master base station, a Secondary Cell Group (SCG) for communicating with a secondary base station, and two MAC entities, one for the MCG for communicating with the master base station and one for the SCG for communicating with the secondary base station.

[0073] FIG. 10 illustrates an example bandwidth portion configuration and switching in accordance with some aspects of various example embodiments of the present disclosure. A UE may be configured with one or more bandwidth portions (BWPs) 1010 in a given component carrier. In some examples, one or One of multiple bandwidth portions may be active at a time. The active bandwidth portion may define the operating bandwidth of the UE within the operating bandwidth of the cell. For initial access, the initial bandwidth portion 1020 determined from the system information may be used until the configuration of the UE in the cell is received. In bandwidth adaptation (BA), for example by BWP switching 1040, the reception and transmission bandwidth of the UE may not be as large as the bandwidth of the cell and may be adjusted. For example, the width may be ordered to change (e.g., shrink during low activity periods to save power), the location may move in the frequency domain (e.g., to increase scheduling flexibility), and the subcarrier spacing may be ordered to change (e.g., to enable different services). The first active BWP 1020 may be the active BWP at the time of RRC (re)configuration of the PCell or activation of the SCell.

[0074] For a downlink BWP or an uplink BWP in a set of downlink or uplink BWPs, respectively, the UE may be provided with the following configuration parameters: subcarrier spacing (SCS), cyclic prefix, common RBs and a number of consecutive RBs, an index in the set of downlink or uplink BWPs by the respective BWP-Id, a set of BWP common parameters and a set of BWP-specific parameters. The BWP may be associated with an OFDM numerology according to the subcarrier spacing and cyclic prefix configured for the BWP. For the serving cell, the UE may be provided with a default downlink BWP among the configured downlink BWPs. If the UE is not provided with a default downlink BWP, the default downlink BWP may be the initial downlink BWP.

[0075] A downlink BWP may be associated with a BWP inactivity timer. If a BWP inactivity timer associated with an active downlink BWP expires and a default downlink BWP is configured, the UE may perform a BWP switch to the default BWP. If a BWP inactivity timer associated with an active downlink BWP expires and a default downlink BWP is not configured, the UE may perform a BWP switch to an initial downlink BWP.

[0076] FIG. 11 illustrates an exemplary 4-step contention-based and contention-free random access process according to some aspects of various exemplary embodiments of the present disclosure. FIG. 12 illustrates an exemplary 2-step contention-based and contention-free random access process according to some aspects of various exemplary embodiments of the present disclosure. The random access procedure can be triggered by several events, such as initial access from an RRC idle state, an RRC connection re-establishment procedure, downlink or uplink data arrival during an RRC connected state when the uplink synchronization state is "unsynchronized", uplink data arrival during an RRC connected state when there are no PUCCH resources available for a Scheduling Request (SR), an SR failure, a request by RRC upon synchronization reconfiguration (e.g., handover), a transition from an RRC inactive state, establishing time alignment of the secondary TAG, a request for other system information (SI), beam failure recovery (BFR), and a consistent uplink listen-before-talk (LBT) failure on the PCell.

[0077] Two types of random access (RA) procedures can be supported: a four-step RA type with MSG1 and a two-step RA type with MSGA. Both types of RA procedures can support contention-based random access (CBRA) and contention-free random access (CFRA), as shown in Figures 11 and 12.

[0078] The UE shall select the random access node at the beginning of the random access procedure based on the network configuration. If the CFRA resource is not configured, the RSRP threshold may be used by the UE to select between the 2-step RA type and the 4-step RA type. If the CFRA resource for the 4-step RA type is configured, the UE can perform random access using the 4-step RA type. If the CFRA resource for the 2-step RA type is configured, the UE can perform random access using the 2-step RA type.

[0079] MSG1 of the four-step RA type may consist of a preamble in the PRACH. After MSG1 transmission, the UE may monitor for a response from the network within a configured window. In the case of CFRA, a dedicated preamble for MSG1 transmission is assigned by the network, and upon receiving a random access response (RAR) from the network, the UE may terminate the random access procedure as illustrated in FIG. 11. In the case of CBRA, upon receiving the random access response, the UE may transmit MSG3 using the uplink grant scheduled in the random access response and may monitor contention resolution as illustrated in FIG. 11. If contention resolution is not successful after MSG3 (re)transmission, the UE may return to MSG1 transmission.

[0080] The MSGA of the two-step RA type may include a preamble in the PRACH and a payload in the PUSCH. After the MSGA transmission, the UE may monitor for a response from the network within a configured window. In the case of CFRA, a dedicated preamble and PUSCH resources may be configured for the MSGA transmission, and upon receiving a network response, the UE may terminate the random access procedure as shown in FIG. 12. In the case of CBRA, if the contention resolution is successful upon receiving the network response, the UE may terminate the random access procedure as shown in FIG. 12, while if a fallback indication is received in the MSGB, the UE may perform an MSG3 transmission using the uplink grant scheduled with the fallback indication and monitor the contention resolution. If the contention resolution is not successful after the MSG3 (re)transmission, the UE may return to the MSGA transmission.

[0081] FIG. 13 illustrates an example time and frequency structure of a synchronization signal and a physical broadcast channel (PBCH) block (SSB) according to some aspects of various exemplary embodiments of the present disclosure. The SS / PBCH block (SSB) may consist of a primary synchronization signal and a secondary synchronization signal (PSS, SSS), each occupying one symbol and 127 subcarriers (e.g., subcarrier numbers 56 to 182 in FIG. 13), and a PBCH that spans three OFDM symbols and 240 subcarriers, but leaves an unused portion in the center for the SSS on one symbol as shown in FIG. 13. The possible time positions of the SSBs within a half frame may be determined by the subcarrier spacing, and the periodicity of the half frame during which the SSBs are transmitted may be configured by the network. During a half frame, different SSBs may be transmitted in different spatial directions (i.e., using different beams spanning the coverage area of ​​the cell).

[0082] The PBCH may be used to carry the Master Information Block (MIB) used by the UE during cell search and initial access procedures. The UE may first decode the PBCH / MIB to receive other system information. The MIB may provide the UE with the necessary parameters to obtain System Information Block 1 (SIB1), more specifically, the necessary information to monitor the PDCCH for scheduling the PDSCH carrying SIB1. Additionally, the MIB may indicate cell barring status information. The MIB and SIB1 may be collectively referred to as Minimum System Information (SI), and SIB1 may be referred to as Remaining Minimum System Information (RMSI). The other System Information Blocks (SIBs) (e.g., SIB2, SIB3, ..., SIB10, and SIBpos) may be referred to as the other SIs. Other SI may be broadcast periodically on the DL-SCH, may be broadcast on demand on the DL-SCH (e.g., upon request from a UE in RRC idle, RRC inactive, or RRC connected state), or may be sent in a dedicated manner to RRC connected UEs on the DL-SCH (e.g., upon request, if configured by the network, from a UE in RRC connected state, or if the UE has an active BWP for which a common search space is not configured).

[0083] FIG. 14 illustrates an exemplary SSB burst transmission according to some aspects of various exemplary embodiments of the present disclosure. The SSB burst may include N SSBs, and each SSB of the N SSBs may correspond to a beam. The SSB burst may be transmitted according to a periodicity (e.g., SSB burst period). During a contention-based random access process, the UE may perform a random access resource selection process, in which the UE first selects an SSB before selecting an RA preamble. The UE may select an SSB with an RSRP above a set threshold. In some embodiments, the UE may select any SSB if an SSB with an RSRP above a set threshold is not available. A set of random access preambles may be associated with the SSB. After selecting the SSB, the UE may select a random access preamble from the set of random access preambles associated with the SSB and may transmit the selected random access preamble to initiate the random access process.

[0084] In some embodiments, a beam among the N beams may be associated with a CSI-RS resource. The UE may measure the CSI-RS resource and select a CSI-RS with an RSRP above a configured threshold. The UE may select a random access preamble corresponding to the selected CSI-RS and transmit the selected random access process to initiate the random access process. If there is no random access preamble associated with the selected CSI-RS, the UE may select a random access preamble corresponding to an SSB quasi-co-located with the selected CSI-RS.

[0085] In some embodiments, based on the UE measurements of CSI-RS resources and the UE CSI report, the base station can determine a transmission configuration indication (TCI) state and can indicate the TCI state to the UE, and the UE can use the indicated TCI state for reception of downlink control information (e.g., via PDCCH) or data (e.g., via PDSCH). The UE can use the indicated TCI state to use an appropriate beam for reception of data or control information. The indication of the TCI state can be using an RRC configuration or a combination of RRC signaling and dynamic signaling (e.g., via a MAC Control Element (MAC CE) and / or based on the value of a field in the downlink control information that schedules the downlink transmission). The TCI state can indicate a quasi-co-location (QCL) relationship between a downlink reference signal, such as a CSI-RS, and a DM-RS associated with a downlink control or data channel (e.g., PDCCH or PDSCH, respectively).

[0086] In some embodiments, the UE may be configured with a list of up to M TCI-state configurations, where M may depend on the UE capabilities, using a physical downlink shared channel (PDSCH) configuration parameter to decode the PDSCH according to the detected PDCCH with DCI for the UE and a given serving cell. Each TCI-State may be a QC state between one or two downlink reference signals and the DM-RS port of the PDSCH, the DM-RS port of the PDCCH, or the CSI-RS port of the CSI-RS resources. The quasi-co-location relationship may include parameters for configuring the L relationship. The quasi-co-location relationship may be configured by one or more RRC parameters. The quasi-co-location type corresponding to each DL RS may take one of the following values: "QCL-TypeA": {Doppler shift, Doppler spread, average delay, delay spread}, "QCL-TypeB": {Doppler shift, Doppler spread}, "QCL-TypeC": {Doppler shift, average delay}, "QCL-TypeD": {Spatial Rx parameters}. The UE may receive an activation command (e.g., MAC CE) used to map the TCI state to a code point in the DCI field.

[0087] FIG. 15 illustrates exemplary components of a user equipment and a base station for transmission and / or reception according to some aspects of various exemplary embodiments of the present disclosure. All or a subset of the blocks and functions in FIG. 15 may be in or performed by the base station 1505 and the user equipment 1500. The antenna 1510 may be used to transmit or receive electromagnetic signals. The antenna 1510 may include one or more antenna elements and may enable different input / output antenna configurations including a multiple-input multiple-output (MIMO) configuration, a multiple-input single-output (MISO) configuration, and a single-input multiple-output (SIMO) configuration. In some embodiments, the antenna 150 may enable a massive MIMO configuration with tens or hundreds of antenna elements. The antenna 1510 may enable other multi-antenna techniques such as beamforming. In some examples, depending on the capabilities of the UE 1500 or the type of the UE 1500 (e.g., a low-complexity UE), the UE 1500 may support only a single antenna.

[0088] The transceiver 1520 can communicate bidirectionally over wireless links as described herein via the antenna 1510. For example, the transceiver 1520 may represent a wireless transceiver in a UE and may communicate bidirectionally with a wireless transceiver in a base station, or vice versa. The transceiver 1520 can include a modem for modulating packets, providing the modulated packets to the antenna 1510 for transmission, and demodulating packets received from the antenna 1510.

[0089] The memory 1530 can include RAM and ROM. The memory 1530 can store computer readable computer executable code 1535 that includes instructions that, when executed, cause the processor to perform various functions described herein. In some examples, the memory 1530 can include a basic input / output system (BIOS) that can control basic hardware or software operations such as interaction with peripheral components or devices, among other things.

[0090] The processor 1540 may include a hardware device having processing capabilities (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some examples, the processor 1540 may be configured to operate a memory using a memory controller. In other examples, the memory controller may be integrated into the processor 1540. The processor 1540 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1530) to cause the UE 1500 or the base station 1505 to perform various functions.

[0091] A central processing unit (CPU) 1550 may perform basic arithmetic, logical, control, and input / output (I / O) operations specified by computer instructions in memory 1530. User equipment 1500 and / or base station 1505 may include a graphics processing unit. The user equipment 1500 may include additional peripheral components such as a graphics processing unit (GPU) 1560 and a global positioning system (GPS) 1570. The GPU 1560 is dedicated circuitry for rapid manipulation and modification of memory 1530 to accelerate processing performance of the user equipment 1500 and / or base station 1505. The GPS 1570 may be used to enable location-based services or other services, for example, based on the geographic location of the user equipment 1500.

[0092] In some examples, a phase tracking reference signal (PT-RS) can be used to enable compensation of oscillator phase noise in a frequency range / band (e.g., FR1 or FR2 or frequency bands above 6 GHz). Phase noise can increase as a function of carrier frequency. PT-RS can be utilized at high frequencies (e.g., mmWave bands) to mitigate phase noise effects. For OFDM signals, the effect of phase noise can be a phase rotation of the subcarriers, known as common phase error (CPE).

[0093] In some examples, the PT-RS may be designed to have low density in the frequency domain and high density in the time domain. In some examples, the source of phase rotation by the CPE may be similar for subcarriers within an OFDM symbol, and correlation between OFDM symbols may be minimal.

[0094] In some embodiments, the PT-RS may be UE specific and may be restricted to scheduled resources (e.g., scheduled resources for transmission of a transport block via PDSCH, PUSCH, or PSSCH). In some examples, the PT-RS may be beamformed. In some examples, the number of PT-RS ports may be less than the total number of ports, and orthogonality between the PT-RS ports may be achieved by frequency division multiplexing. The PT-RS may be configurable depending on the oscillator quality, carrier frequency, OFDM subcarrier spacing, and modulation and coding scheme (MCS) used for transmission.

[0095] In some examples, the PT-RS may be used for time and frequency tracking and / or estimation of delay and / or Doppler spread at the UE side. The PT-RS signal may be transmitted within a limited bandwidth for a configurable duration controlled by an RRC parameter.

[0096] In some examples, the time-frequency structure of the PT-RS may depend on the waveform. Exemplary time-domain and frequency-domain structures of the PT-RS are shown in FIG. 16 and FIG. 17, respectively. In the case of OFDM, the first reference symbol in the PDSCH / PUSCH allocation (e.g., before applying the orthogonal sequence) may be repeated every {1,2,4} symbols starting from the first OFDM symbol in the allocation (e.g., PDSCH / PUSCH / PSSCH allocation). The repetition counter may be reset at the DM-RS opportunity, and a PT-RS transmission immediately after the DM-RS opportunity may not be necessary. In some examples, in the frequency domain, the PT-RS may be transmitted every second or fourth resource block, resulting in a sparser frequency domain structure. The density in the frequency domain may depend on the scheduled bandwidth. In some examples, to reduce the risk of collision between PT-RS signals associated with different devices scheduled on overlapping frequency domain resources, the subcarrier number and the resource block used for the PT-RS transmission may be determined based on a radio network temporary identifier (e.g., C-RNTI) associated with the device.

[0097] In some examples, different sequence generation and resource mapping processes may be used for transmission of the PT-RS over the PDSCH, PUSCH, or PSSCH.

[0098] In some examples, for a phase tracking reference signal used for transmission via the PUSCH, different processes may be used depending on whether transform precoding is enabled. If transform precoding is not enabled, a first PT-RS sequence generation process may be used. The precoded phase tracking reference signal for subcarrier k on tier j may be given by equation (1).

number

number

[0099] In one example, to demonstrate the use of chirp signals for PT-RS sequence generation, a subcarrier spacing of 60 KHz can be used, which translates to a symbol time of 16.67 us. The chirp formula may be based on Equation (3).

number

[0100] In some examples, if transform precoding is not enabled, the PUSCH PT-RS may be mapped to resource elements according to equation (4) if all of the following conditions are met:

number

number

[0101] In some examples, for a phase tracking reference signal used for transmission over the PDSCH, for subcarrier k, a sequence based on a chirp signal may be used. Details of the chip signal are described below. The UE may assume that the phase tracking reference signal is only present in resource blocks used for the PDSCH. If present, the UE may adjust the factor β so that the PDSCH PT-RS is adapted to the transmit power if all of the following conditions are met: PT-RS,i and the resource element (k,l) is scaled by p,μ It can be assumed that the

number

[0102] The set of time indexes l defined for the start of the PDSCH allocation may be defined based on the process.

[0103] In some examples, for a phase tracking reference signal used for transmission over the PSSCH, the precoded sidelink phase tracking reference signal for subcarrier k on tier j may be given by equation (7).

number

number

[0104] The PSSCH PT-RS may be mapped to resource elements according to equation (9) if all of the following conditions are satisfied:

number

number

[0105] In some examples, the precoding matrix W may be predetermined.

[0106] In some examples, the IE DMRS-DownlinkConfig may be used to configure a downlink demodulation reference signal for the PDSCH. The field phaseTrackingRS may configure a downlink PTRS. If this field is not set, the UE may assume that no downlink PT-RS is present. In one example, the IE DMRS-UplinkConfig may be used to configure an uplink demodulation reference signal for the PUSCH. The field phaseTrackingRS may configure an uplink PT-RS.

[0107] In some examples, the IE PTRS-DownlinkConfig may be used to configure the downlink phase tracking reference signal (PT-RS). The field epre-Ratio may indicate an energy per resource element (EPRE) ratio between PTRS and PDSCH. The field frequencyDensity may indicate the presence and frequency density of DL PT-RS as a function of scheduled bandwidth. If this field is not present, the UE may use K_PT-RS=2. The field maxNrofPorts may indicate the maximum number of DL PTRS ports. The field resourceElementOffset may indicate a subcarrier offset for DL ​​PT-RS. The field timeDensity may indicate the presence and time density of DL PT-RS as a function of MCS.

[0108] In some examples, the IE PTRS-UplinkConfig may be used to configure an uplink phase tracking reference signal (PT-RS). The field frequencyDensity may indicate the presence and frequency density of UL PT-RS with respect to the CP-OFDM waveform as a function of scheduled BW. The field maxNrofPorts may indicate the maximum number of UL PTRS ports for CP-OFDM. The field ptrs-Power may indicate an uplink PTRS power boost factor per PTRS port. The field resourceElementOffset may indicate a subcarrier offset of the UL PTRS for CP-OFDM. The field sampleDensity may indicate a set of thresholds T={NRBn, n=0,1,2,3,4} for DFT-s-OFDM, pre-DFT The sample density of the PT-RS may be indicated, which indicates a dependency between the presence of the PT-RS and the scheduled bandwidth, and the values ​​of X and K that the UE should use depending on the scheduled bandwidth. The field timeDensity may indicate the presence and time density of the UL PT-RS for a CP-OFDM waveform as a function of MCS. The field timeDensityTransformPrecoding may indicate the time density (OFDM symbol level) of the PT-RS for DFT-s-OFDM. The field transformPrecoderDisabled may indicate the configuration of the UL PTRS without a transform precoder (with CP-OFDM). The field transformPrecoderEnabled may indicate the configuration of the UL PTRS with a transform precoder (DFT-S-OFDM).

[0109] In some examples, the IE SL-ResourcePool can specify configuration information for the NR sidelink communications resource pool. The IE SL-ResourcePool can include an sl-PTRS-Config IE indicating parameters such as frequency density, time density, and PT-RS resource element offsets.

[0110] In some examples, when transform precoding is not enabled and the UE is configured with the higher layer parameter phaseTrackingRS in DMRS-UplinkConfig, the higher layer parameters timeDensity and frequencyDensity in PTRS-UplinkConfig may indicate thresholds ptrs-MCSi,i=1,2,3 and NRB,i,i=0,1 used in PT-RS sequence generation and / or mapping.

[0111] In some examples, if transform precoding is not enabled and the UE is configured with the higher layer parameter phaseTrackingRS in DMRS-UplinkConfig, then if one or both of the higher layer parameters timeDensity and / or frequencyDensity in PTRS-UplinkConfig are configured, the UE may assume that the presence and pattern of PT-RS antenna ports is a function of the corresponding scheduled MCS and scheduled bandwidth in the corresponding bandwidth portion. If the higher layer parameter timeDensity is not configured, the UE may assume LPT-RS=1. If the higher layer parameter frequencyDensity is not set, the UE shall assume KPT-RS=2.

[0112] In some examples, if transform precoding is not enabled and the UE is configured with the higher layer parameter phaseTrackingRS in DMRS-UplinkConfig, and none of the higher layer parameters timeDensity and frequencyDensity in PTRS-UplinkConfig are configured, the UE may assume LPT-RS=1 and KPT-RS=2.

[0113] In some examples, if the higher layer parameter PTRS-UplinkConfig indicates a time density threshold ptrs-MCSi = ptrs-MCSi + 1, the time density LPTRS of the associated row may be disabled. If the higher layer parameter frequencyDensity in PTRS-UplinkConfig indicates a frequency density threshold NRB,i = NRB,i + 1, the frequency density KPTRS of the associated row may be disabled.

[0114] In some examples, if either or both of the parameters PT-RS Time Density (LPT-RS) and PT-RS Frequency Density (KPT-RS) indicate that they are configured as "no PT-RS," the UE may assume that no PT-RS is present.

[0115] In some examples, if the UE is scheduled to transmit a PUSCH with an allocation duration of 2 symbols or less, the UE may not transmit a PT-RS if LPT-RS is set to 2 or 4. If the UE is scheduled to transmit a PUSCH with an allocation duration of 4 symbols or less, the UE may not transmit a PT-RS if LPT-RS is set to 4.

[0116] In some examples, the maximum number of configured PT-RS ports may be given by the higher layer parameter maxNrofPorts in PTRS-UplinkConfig. A UE may not be expected to be configured with more UL PT-RS ports than its reported need.

[0117] In some examples, if a UE reports an ability to support fully coherent UL transmission, the UE may expect the number of UL PT-RS ports to be configured as one if a UL-PTRS is configured.

[0118] In some examples, for codebook or non-codebook based UL transmission, The association between the PT-RS and DM-RS ports may be signaled by the PTRS-DMRS association field in DCI Format 0_1 ​​and DCI Format 0_2. For a PUSCH corresponding to a configured grant type 1 transmission, the UE may assume an association between the UL PT-RS and DM-RS ports based on one or more tables.

[0119] In some examples, for a PUSCH scheduled by DCI format 0_0 or activated DCI format 0_0, the UL PT-RS port may be associated with DM-RS port 0.

[0120] In some examples, for non-codebook based UL transmission, the actual number of UL PT-RS ports to transmit may be determined based on the higher layer parameter sri-ResourceIndicator of SRI or rrc-ConfiguredUplinkGrant in DCI format 0_1 ​​and DCI format 0_2. If the UE is configured with the higher layer parameter phaseTrackingRS in DMRS-UplinkConfig, the UE is configured with the PT-RS port index of each configured SRS resource by the higher layer parameter ptrs-PortIndex configured by SRS-Config. If the PT-RS port indexes associated with different SRIs are the same, the corresponding UL DM-RS ports may be associated with one UL PT-RS port.

[0121] In some examples, when a UE is scheduled with Qp={1,2} PT-RS ports in the uplink and the number of scheduled layers is equation (11), if the UE is configured with upper layer parameter ptrs-Power, the PUSCH-to-PT-RS power ratio per layer per RE (equation (12)) may be given by equation (13), where equation (14) may be the upper layer parameter ptrs-Power, and the PT-RS scaling factor β PTRSmay be given by equation (15), and may also be given by the precoding information and number of layers fields of the DCI.

number

number

number

number

number

[0122] In some examples, when transform precoding is enabled and the UE is configured with the higher layer parameter transformPrecoderEnabled in PTRS-UplinkConfig, the UE may be configured with the higher layer parameter sampleDensity, and the UE may assume that the PT-RS antenna port presence and the PT-RS group pattern are a function of the corresponding scheduled bandwidth of the corresponding bandwidth portion. If NRB0>1, or if the number of scheduled RBs is less than NRB0 when RNTI is equal to TC-RNTI, the UE may assume that the PT-RS is not present. The UE may be configured with the higher layer parameter timeDensityTransformPrecoding for PT-RS time density LPT-RS=2. Otherwise, the UE may assume LPT-RS=1.

[0123] In some examples, PT-RS reception may be used by UEs receiving a PDSCH scheduled by DCI format 1_2 configured with the higher layer parameter phaseTrackingRS of dmrs-DownlinkForPDSCH-MappingTypeA-ForDCI-Format1-2-r16 or dmrs-DownlinkForPDSCH-MappingTypeB-ForDCI-Format1-2-r16, as well as by UEs receiving a PDSCH scheduled by DCI format 1_0 or DCI format 1_1 configured with the higher layer parameter phaseTrackingRS of dmrs-DownlinkForPDSCH-MappingTypeA or dmrs-DownlinkForPDSCH-MappingTypeB.

[0124] In some examples, the UE may report a preferred MCS and bandwidth threshold for each subcarrier spacing applicable to a data channel at a given carrier frequency based on the UE capabilities at that carrier frequency, given an MCS table with the maximum modulation order that it reports as supported.

[0125] In some examples, the UE may be configured with the higher layer parameter phaseTrackingRS in DMRS-DownlinkConfig. The higher layer parameters timeDensity and frequencyDensity in PTRS-DownlinkConfig may indicate thresholds ptrs-MCSi,i=1,2,3 and NRB,i,i=0,1.

[0126] In some examples, the UE may be configured with the higher layer parameter phaseTrackingRS in DMRS-DownlinkConfig. If one or both of the additional higher layer parameters timeDensity and frequencyDensity are configured and the RNTI is equal to MCS-C-RNTI, C-RNTI, or CS-RNTI, the UE may assume that the presence and pattern of PT-RS antenna ports is a function of the corresponding scheduled MCS of the corresponding codeword and the scheduled bandwidth of the corresponding bandwidth portion. If the higher layer parameter timeDensity given by PTRS-DownlinkConfig is not configured, the UE may assume LPT-RS=1. If the higher layer parameter frequencyDensity given by PTRS-DownlinkConfig is not configured, the UE may assume KPT-RS=2.

[0127] In some examples, if the UE is not configured with the higher layer parameter phaseTrackingRS in DMRS-DownlinkConfig, the UE may assume that the PT-RS is not present.

[0128] In some examples, the higher layer parameter PTRS-DownlinkConfig may provide parameters ptrs-MCSi,i=1,2,3.

[0129] In some examples, if the higher layer parameter PTRS-DownlinkConfig indicates a time density threshold ptrs-MCSi=ptrs-MCSi+1, the associated time density LPT-RS may be disabled. If the higher layer parameter PTRS-DownlinkConfig indicates a frequency density threshold NRBi=NRBi+1, the frequency density KPTRS of the associated row may be disabled.

[0130] In some examples, if either or both of the parameters PT-RS time density (LPT-RS) and PT-RS frequency density (KPT-RS) indicate "no PT-RS," the UE may assume that no PT-RS is present.

[0131] In some examples, if a UE is receiving a PDSCH with an allocation duration of 2 symbols, if the LPT-RS is set to 2 or 4, the UE may assume that the PT-RS is not transmitted.

[0132] In some examples, if a UE is receiving a PDSCH with an allocation duration of 4 symbols, if LPT-RS is set to 4, the UE may assume that no PT-RS is transmitted.

[0133] In some examples, the DL DM-RS port associated with a PT-RS port may be assumed to be quasi-co-located with respect to {"QCL-TypeA" and "QCL-TypeD"}. If the UE is scheduled with one codeword, the PT-RS antenna port may be associated with the lowest indexed DM-RS antenna port among the DM-RS antenna ports assigned for the PDSCH.

[0134] In some examples, if a UE is scheduled with two codewords, the PT-RS antenna port may be associated with the lowest indexed DM-RS antenna port among the DM-RS antenna ports assigned to the codeword with the higher MCS, and if the MCS index of the two codewords is the same, the PT-RS antenna port may be associated with the lowest indexed DM-RS antenna port assigned to codeword 0.

[0135] In some examples, if the UE is not indicated by the DCI that the DCI field "Time Domain Resource Allocation" indicates an entry including repetitionNumber-r16 in PDSCH-TimeDomainResourceAllocation-r16, if the UE is configured with the higher layer parameter maxNrofPorts equal to n2, and if the UE is indicated in two TCI states by the codepoints in the DCI field "Transmission Configuration Indication" and the DM-RS ports in two CDM groups in the DCI field "Antenna Ports", the UE may receive two PT-RS ports that may be associated with the lowest indexed DM-RS port among the DM-RS ports corresponding to the first / second indicated TCI states, respectively.

[0136] In some examples, when a UE configured with higher layer parameter RepetitionScheme-r16 set to "FDMSchemeA" or "FDMSchemeB" is indicated with two TCI states in the DCI field codepoint and a transmission configuration indication and a DM-RS port in one CDM group in the DCI field "antenna port", the UE may receive a single PT-RS port that may be associated with the lowest indexed DM-RS antenna port among the DM-RS antenna ports assigned to the PDSCH, the PT-RS frequency density is determined by the number of PRBs associated with each TCI state, and a PT-RS resource element mapping may be associated with the assigned PRB of each TCI state.

[0137] Phase tracking is important for the correct functioning of any wireless system. Even small disparities in phase can lead to increased errors and thus degraded system performance. Phase error can be described as a small frequency mismatch that can result in delay between the transmitter and receiver signals. In some instances, phase differences can occur because the clocks of the remote devices are not perfectly aligned. Even small differences in frequency can translate into phase offsets, which can lead to high bit error rates. The receiver can implement processes to combat the phase differences. Exemplary embodiments are based on utilizing chirp signals to enhance PT-RS signal generation in the downlink, uplink, and sidelink and enhance phase tracking performance at the UE or base station.

[0138] In some examples, a chirp signal may be used for the phase tracking reference signal. The chirp signal may be demodulated with the same chirp signal. If there is no delay, the chirp signal may be demodulated as a constant discrete component (DC) component. If there is a delay, the delay may cause an actual frequency offset, which may lead to a tone at a specific frequency. This frequency may be detected by using a fast frequency transform (FFT) process.

[0139] The frequency of the chirp signal may vary over time. An example is shown in Figure 18. The chirp signal is given by c(t)=Ae -j(ω+δt)t The frequency of the signal increases over time based on the chirp factor δ. If a signal is demodulated with another signal that has a small offset, the amplitude of the demodulated signal will change, indicating that there is an offset and can be used to compensate for phase noise.

[0140] In the example embodiment shown in FIG. 19, the UE may receive one or more messages (e.g., one or more RRC messages) from the gNB that include configuration parameters. The configuration parameters may include uplink PT-RS configuration parameters. For example, the one or more messages may include a Phase Tracking Reference Signal (PT-RS) Uplink Configuration Information Element (e.g., PTRS-Uplink) that indicates uplink PT-RS configuration parameters. The uplink PT-RS configuration parameters may include a DCI (e.g., DCI Format 0_0, DCI Format 0_1, or DCI Format 0_2) including an uplink grant indicating radio resources for transmission of the uplink TB via the PUSCH. The PUSCH may be scheduled for transmission via a cell in a first frequency range / frequency band. For example, the cell may be in the FR2 frequency range (e.g., above 6 GHz). The UE may transmit a PT-RS signal via the radio resources of the PUSCH used for transmission of the uplink TB. The uplink PT-RS signal may be used by the gNB for compensation of oscillator phase noise. The UE may transmit a PT-RS signal based on the PT-RS configuration parameters, a PT-RS sequence generation process used to generate a PT-RS sequence, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of a PUSCH allocated for transmission of an uplink TB. The PT-RS sequence generation may use the chirp signal described above depending on a chirp factor (e.g., δ). In some examples, the chirp factor may be indicated by an RRC parameter (e.g., based on an uplink PT-RS configuration parameter). In some examples, the chirp factor may be a predefined value. In some examples, a DCI (e.g., a DCI used to schedule a PUSCH / uplink TB) may indicate the chirp factor. For example, the DCI may include a value of a field indicating the chirp factor. In some examples, the UE may receive a MAC CE indicating the chirp factor used for sequence generation of the PT-RS signal. The chirp signal may be associated with a time-varying frequency, where the variation level of the frequency may depend on the chirp factor.In some examples, the PT-RS sequence generation process may be different when transform precoding is enabled than when transform precoding is not enabled. For example, the UE may use a first sequence generation process when transform precoding is not enabled, and may use a second sequence generation process when transform precoding is enabled. In some examples, both the first process and the second process may be based on one or more chirp signals. The UE may map the generated PT-RS sequence to resource elements of a PUSCH and may transmit the PT-RS signal to the gNB via the PUSCH resource. The mapping process may include determining a subcarrier to which the PT-RS signal is mapped. In some examples, the mapping of the PT-RS signal to the PUSCH resource may be such that the PT-RS signal is more sparse in the frequency domain compared to the time domain.

[0141] The generation and mapping of PT-RS signals may be based on uplink PT-RS configuration parameters. For example, the uplink PT-RS configuration parameters may include a frequency density parameter indicating the presence and frequency density of PT-RS as a function of the scheduled bandwidth of the physical uplink shared channel (PUSCH). The UE may determine the density of PT-RS signals in the frequency domain and thus map the PT-RS signals to PUSCH resources based on the frequency density parameter. For example, the uplink PT-RS configuration parameters may include a parameter (e.g., maxNrofPort) indicating the maximum number of uplink PT-RS ports. The UE may use the value of this parameter for the transmission of PT-RS signals. For example, the uplink PT-RS configuration parameters may include a parameter indicating an uplink PT-RS boost factor per PT-RS port, e.g., for determining the PUSCH to PT-RS power ratio and for determining the PT-RS power. For example, the uplink PT-RS configuration parameters may include a resource element offset parameter indicating a subcarrier offset for the uplink PT-RS that may be used in the PT-RS mapping process. For example, the uplink PT-RS configuration parameters may include a sample density parameter indicating a sample density of the PT-RS for discrete frequency transform (DFT) spread orthogonal frequency division multiplexing (OFDM), pre-DFT, indicating a set of thresholds indicating a dependency between the presence of the PT-RS and the scheduled bandwidth of the physical uplink shared channel (PUSCH). For example, the uplink PT-RS configuration parameters may include a time density parameter indicating the presence and time density of the PT-RS as a function of the modulation and coding scheme (MCS). The UE may determine the density of the PT-RS signal in the time domain and thus map the PT-RS signal to the PUSCH resource based on the time density parameter. For example, the uplink PT-RS configuration parameters may include a time density transform precoding parameter indicating the time density of the PT-RS for discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) at the OFDM symbol level. For example, the uplink phase tracking reference signal (PT-RS) configuration parameters include one or more parameters indicating whether the uplink PT-RS is configured with a cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) waveform.

[0142] In the exemplary embodiment shown in FIG. 20, the UE may receive one or more messages (e.g., one or more RRC messages) including configuration parameters from the gNB. The configuration parameters may include downlink PT-RS configuration parameters. For example, the one or more messages may include a Phase Tracking Reference Signal (PT-RS) Downlink Configuration Information Element (e.g., PTRS-DownlinkConfig IE) indicating the downlink PT-RS configuration parameters. The downlink PT-RS configuration parameters may be used by the UE for reception / detection of PT-RS sequences and / or mapping of PT-RS sequences to radio resources (e.g., resource elements in a PDSCH assignment). In one example, the UE may receive a DCI (e.g., DCI Format 1_0, DCI Format 1_1, or DCI Format 1_2) including a downlink assignment indicating radio resources for receiving downlink TBs via a PDSCH. The PDSCH may be scheduled for reception of downlink TBs via a cell in a first frequency range / frequency band. For example, the cell may be in the FR2 frequency range (e.g., above 6 GHz). The UE may receive the PT-RS signal via the radio resource of the PDSCH used for receiving the downlink TB. The UE may compensate for oscillator phase noise based on the received downlink PT-RS signal. In some examples, the UE may perform one or more of time and frequency tracking, delay spread estimation, and Doppler spread estimation based on the received PT-RS signal. The UE may receive the PT-RS signal based on the PT-RS configuration parameters, a PT-RS sequence generation process used to generate the PT-RS sequence, and a PT-RS mapping process for mapping the generated PT-RS sequence to the radio resource of the PDSCH allocated for transmitting the downlink TB. The PT-RS sequence generation may use the chirp signal described above depending on a chirp factor (e.g., δ). In some examples, the chirp factor may be indicated by an RRC parameter (e.g., based on the downlink PT-RS configuration parameters).In some examples, the chirp factor may be a predefined value. In some examples, the DCI (e.g., DCI used to schedule the PDSCH / downlink TB) may indicate the chirp factor. For example, the DCI may include a value of a field indicating the chirp factor. In some examples, the UE may receive a MAC CE indicating the chirp factor used for sequence generation of the PT-RS signal. The chirp signal may be associated with a time-varying frequency, where the frequency variation level may depend on the chirp factor. The generated PT-RS sequence may be mapped to resource elements of the PDSCH. The gNB may transmit the PT-RS signal to the UE via the PDSCH resource. The mapping process may determine the subcarriers to which the PT-RS signal is mapped. In some examples, the mapping of the PT-RS signals to the PDSCH resources may be such that the PT-RS signals are sparse in the frequency domain compared to the time domain.

[0143] The generation, mapping, and transmission of the PT-RS signal by the gNB to the UE can be based on downlink PT-RS configuration parameters. For example, the downlink PT-RS configuration parameters can include an energy per resource element (EPRE) ratio parameter indicating an EPRE ratio between the PT-RS and the physical downlink shared channel (PDSCH). For example, the downlink PT-RS configuration parameters can include a frequency density parameter indicating the presence and frequency density of the PT-RS as a function of the scheduled bandwidth of the physical downlink shared channel (PDSCH). The UE can determine the density of the PT-RS signal in the frequency domain and thus determine the mapping of the PT-RS signal to the PDSCH resources based on the frequency density parameter. For example, the downlink PT-RS configuration parameters can include a parameter (e.g., maxNrofPort) indicating the maximum number of downlink PT-RS ports. The UE can use the value of this parameter for reception of the PT-RS signal. For example, the downlink PT-RS configuration parameters can include a resource element offset parameter indicating a subcarrier offset of the downlink PT-RS that can be used in the PT-RS mapping process. For example, the downlink PT-RS configuration parameters may include a time-density parameter indicating the presence and time-density of PT-RS as a function of modulation and coding scheme (MCS). The UE may determine the density of PT-RS signals in the time domain and thus determine the mapping of PT-RS signals to PDSCH resources based on the time-density parameter.

[0144] In the exemplary embodiment illustrated in FIG. 21, the first UE may receive one or more messages (e.g., one or more RRC messages) from the gNB including configuration parameters. The configuration parameters may include sidelink PT-RS configuration parameters. For example, the one or more messages may include a Phase Tracking Reference Signal (PT-RS) sidelink configuration information element (e.g., PTRS-SidelinkConfig IE) indicating the sidelink PT-RS configuration parameters. The sidelink PT-RS configuration parameters may be used by the first UE for generation of a PT-RS sequence and / or mapping of the PT-RS sequence to radio resources (e.g., resource elements in a PSSCH allocation). In one example, the first UE may receive a DCI (e.g., DCI Format 3_0 or DCI Format 3_1) including scheduling information indicating radio resources for transmission of sidelink TB via a PSSCH. The PSSCH may be scheduled for transmission via a cell configured in the sidelink communication (e.g., configured in a sidelink resource pool). The first UE may transmit a PT-RS signal via radio resources of the PSSCH used for transmission of the sidelink TB. The sidelink PT-RS signal received by the second UE from the first UE may be used by the second UE for oscillator phase noise compensation. In some examples, the second UE may perform one or more of time and frequency tracking, delay spread estimation, and Doppler spread estimation based on the PT-RS signal received from the first UE. The first UE may transmit the PT-RS signal based on the PT-RS configuration parameters, a PT-RS sequence generation process used to generate the PT-RS sequence, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PSSCH allocated for sidelink TB transmission. The PT-RS sequence generation may use the chirp signal described above depending on a chirp factor (e.g., δ). In some examples, the chirp factor may be indicated by an RRC parameter (e.g., based on an uplink PT-RS configuration parameter).In some examples, the chirp factor may be a predetermined value. For example, the DCI used to schedule the PSSCH / sidelink TB may indicate a chirp factor. For example, the DCI may include a value of a field indicating the chirp factor. In some examples, the UE may receive a MAC CE indicating a chirp factor used for sequence generation of the PT-RS signal. The chirp signal may be associated with a time-varying frequency, where the level of variation of the frequency may depend on the chirp factor. The first UE may map the generated PT-RS sequence to resource elements of the PUSCH and may transmit the PT-RS signal to the second UE via the PSSCH resource. The mapping process may include determining a subcarrier to which the PT-RS signal is mapped. In some examples, the mapping of the PT-RS signal to the PSSCH resource may be such that the PT-RS signal is more sparse in the frequency domain compared to the time domain.

[0145] The generation and mapping of the PT-RS signals may be based on sidelink PT-RS configuration parameters. For example, the sidelink PT-RS configuration parameters may include a frequency density parameter indicating the presence and frequency density of PT-RS as a function of the scheduled bandwidth of the physical sidelink shared channel (PSSCH). The first UE may determine the density of the PT-RS signals in the frequency domain and accordingly map the PT-RS signals to the PSSCH resources based on the frequency density parameter. For example, the sidelink PT-RS configuration parameters may include a resource element offset parameter indicating a subcarrier offset of the sidelink PT-RS that may be used in the PT-RS mapping process. For example, the sidelink PT-RS configuration parameters may include a time density parameter indicating the presence and time density of PT-RS as a function of the modulation and coding scheme (MCS). The first UE may determine the density of the PT-RS signals in the time domain and thus map the PT-RS signals to the PSSCH resources based on the time density parameter.

[0146] In one embodiment, a user equipment (UE) may receive one or more messages including uplink PT-RS configuration parameters from a base station (BS). The UE may transmit a PT-RS signal to the BS over radio resources of a physical uplink shared channel (PUSCH) based on the uplink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, where the PT-RS sequence is based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PUSCH.

[0147] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a first parameter indicative of a chirp coefficient.

[0148] In some embodiments, the chirp factor may be a predetermined value.

[0149] In some embodiments, the UE may receive downlink control information that includes a field having a value indicative of the chirp factor.

[0150] In some embodiments, the UE may receive a Medium Access Control (MAC) Control Element (CE) indicating the chirp factor.

[0151] In some embodiments, the one or more messages may include a phase tracking reference signal (PT-RS) uplink configuration information element that indicates uplink PT-RS configuration parameters.

[0152] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a frequency density parameter that indicates the presence and frequency density of PT-RS as a function of the scheduled bandwidth of the physical uplink shared channel (PUSCH).

[0153] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a parameter indicating a maximum number of uplink PT-RS ports.

[0154] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a parameter indicating an uplink PT-RS boosting factor per PT-RS port.

[0155] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a resource element offset parameter that indicates a subcarrier offset for the uplink PT-RS.

[0156] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a sample density parameter indicating a sample density of the PT-RS for discrete frequency transform (DFT) spread orthogonal frequency division multiplexing (OFDM), pre-DFT, indicating a set of thresholds indicating a dependency between the presence of the PT-RS and the scheduled bandwidth of the physical uplink shared channel (PUSCH).

[0157] In some embodiments, uplink phase tracking reference signal (PT-RS) configuration parameters may include a time density parameter indicating the presence and time density of PT-RS as a function of modulation and coding scheme (MCS).

[0158] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include a time-density transform precoding parameter that indicates the time density of the PT-RS for discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) at the OFDM symbol level.

[0159] In some embodiments, the uplink phase tracking reference signal (PT-RS) configuration parameters may include one or more parameters indicating whether the uplink PT-RS is configured with a cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) waveform or a discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) waveform.

[0160] In some embodiments, the PT-RS signal may be used to compensate for oscillator phase noise.

[0161] In some embodiments, radio resources of a physical uplink shared channel (PUSCH) may be associated with cells in frequency range 2 (FR2).

[0162] In some embodiments, the UE may receive downlink control information including an uplink grant indicating radio resources of a physical uplink shared channel (PUSCH) for transmission of the uplink transport block. In some embodiments, the downlink control information (DCI) may be one of DCI format 0_0, DCI format 0_1, and DCI format 0_2.

[0163] In some embodiments, a first density of PT-RS signals in the frequency domain may be sparser than a second density of PTR-RS signals in the time domain.

[0164] In some embodiments, the phase tracking reference signal (PT-RS) sequence generation process may include generating a PT-RS sequence based on a first process when transform precoding is not enabled and based on a second process when transform precoding is enabled.

[0165] In some embodiments, a phase tracking reference signal (PT-RS) sequence generation process may include generating values ​​of the PT-RS sequence for different subcarriers onto which the PT-RS sequence is mapped.

[0166] In some embodiments, the phase tracking reference signal (PT-RS) mapping process may include mapping the generated PT-RS sequence to different resource elements within radio resources of a physical uplink shared channel (PUSCH).

[0167] In one embodiment, a user equipment (UE) can receive one or more messages including downlink PT-RS configuration parameters from a base station (BS). The UE can receive a PT-RS signal from the BS over radio resources of a physical downlink shared channel (PDSCH) based on the downlink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, where the PT-RS sequence is based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PDSCH.

[0168] In some embodiments, the downlink phase tracking reference signal (PT-RS) configuration parameters may include a first parameter indicative of a chirp coefficient.

[0169] In some embodiments, the chirp factor may be a predetermined value.

[0170] In some embodiments, the UE may receive downlink control information that includes a field having a value indicative of the chirp factor.

[0171] In some embodiments, the UE may receive a Medium Access Control (MAC) Control Element (CE) indicating the chirp factor.

[0172] In some embodiments, the one or more messages may include a PT-RS Downlink Configuration information element that indicates PT-RS configuration parameters.

[0173] In some embodiments, the downlink phase tracking reference signal (PT-RS) configuration parameters may include an energy per resource element (EPRE) ratio parameter indicating an EPRE ratio between the PT-RS and the physical downlink shared channel (PDSCH).

[0174] In some embodiments, the downlink phase tracking reference signal (PT-RS) configuration parameters may include a frequency density parameter indicating the presence and frequency density of PT-RS as a function of the scheduled bandwidth of the physical downlink shared channel (PDSCH).

[0175] In some embodiments, the downlink phase tracking reference signal (PT-RS) configuration parameters may include a parameter indicating a maximum number of downlink PT-RS ports.

[0176] In some embodiments, the downlink phase tracking reference signal (PT-RS) configuration parameters The data may include a resource element offset parameter indicating a subcarrier offset for the downlink PT-RS.

[0177] In some embodiments, the downlink phase tracking reference signal (PT-RS) configuration parameters may include a time density parameter that indicates the presence and time density of downlink PT-RS as a function of MCS.

[0178] In some embodiments, the UE may compensate for oscillator phase noise based on a received phase tracking reference signal (PT-RS) signal.

[0179] In some embodiments, radio resources of a physical downlink shared channel (PDSCH) may be associated with cells in frequency range 2 (FR2).

[0180] In some embodiments, the UE may perform at least one of time and frequency tracking, delay spread estimation, and Doppler spread estimation based on the received phase tracking reference signal (PT-RS) signal.

[0181] In some embodiments, the UE may receive downlink control information including a downlink assignment indicating radio resources of a physical downlink shared channel (PDSCH) for reception of the downlink transport block. In some embodiments, the downlink control information (DCI) may be one of DCI format 1_0, DCI format 1_1, and DCI format 1_2.

[0182] In some embodiments, a first density of PT-RS signals in the frequency domain may be sparser than a second density of PTR-RS signals in the time domain.

[0183] In some embodiments, a phase tracking reference signal (PT-RS) sequence generation process may include generating values ​​of the PT-RS sequence for different subcarriers onto which the PT-RS sequence is mapped.

[0184] In some embodiments, the phase tracking reference signal (PT-RS) mapping process may include mapping the generated PT-RS sequence to different resource elements within the radio resources of a physical downlink shared channel (PDSCH).

[0185] In an embodiment, a first user equipment (UE) can receive one or more messages from a base station including sidelink PT-RS configuration parameters. The first UE can transmit a PT-RS signal to a second UE over radio resources of a physical sidelink shared channel (PSSCH) based on the sidelink PT-RS configuration parameters, a PT-RS sequence generation process for generating a PT-RS sequence, where the PT-RS sequence is based on a chirp signal having a frequency that varies in time according to a chirp factor, and a PT-RS mapping process for mapping the generated PT-RS sequence to radio resources of the PSSCH.

[0186] In some embodiments, the sidelink phase tracking reference signal (PT-RS) configuration parameters may include a first parameter indicative of a chirp coefficient.

[0187] In some embodiments, the chirp factor may be a predetermined value.

[0188] In some embodiments, the first UE and / or the second UE may indicate a chirp factor. The downlink control information may include a field having a value that indicates whether the downlink control information is to be transmitted to the

[0189] In some embodiments, the first UE and / or the second UE may receive a Medium Access Control (MAC) Control Element (CE) indicating the chirp factor.

[0190] In some embodiments, the one or more messages may include a Phase Tracking Reference Signal (PT-RS) sidelink configuration information element that indicates sidelink PT-RS configuration parameters.

[0191] In some embodiments, the sidelink phase tracking reference signal (PT-RS) configuration parameters may include a frequency density parameter indicating the presence and frequency density of PT-RS as a function of the scheduled bandwidth of the physical sidelink shared channel (PSSCH).

[0192] In some embodiments, the sidelink phase tracking reference signal (PT-RS) configuration parameters may include a resource element offset parameter that indicates a subcarrier offset of the sidelink PT-RS.

[0193] In some embodiments, the sidelink phase tracking reference signal (PT-RS) configuration parameters may include a time-density parameter that indicates the presence and time-density of sidelink PT-RS as a function of MCS.

[0194] In some embodiments, the PT-RS signal may be used to compensate for oscillator phase noise by a second user equipment (UE).

[0195] In some embodiments, a phase tracking reference signal (PT-RS) signal may be used for at least one of time and frequency tracking, delay spread estimation, and Doppler spread estimation.

[0196] In some embodiments, the first UE may receive downlink control information including sidelink scheduling parameters indicating radio resources of a physical downlink shared channel (PSSCH) for transmission of the sidelink transport block. In some embodiments, the downlink control information (DCI) may be one of DCI format 3_0 and DCI format 3_1.

[0197] In some embodiments, a first density of PT-RS signals in the frequency domain may be sparser than a second density of PTR-RS signals in the time domain.

[0198] In some embodiments, a phase tracking reference signal (PT-RS) sequence generation process may include generating values ​​of the PT-RS sequence for different subcarriers onto which the PT-RS sequence is mapped.

[0199] In some embodiments, the phase tracking reference signal (PT-RS) mapping process may include mapping the generated PT-RS sequence to different resource elements within the radio resources of the physical sidelink shared channel (PSSCH).

[0200] The example blocks and modules described in this disclosure with respect to various example embodiments may be implemented using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware, or the like. The processor may be implemented or performed using a combination of hardware components, or any combination thereof designed to perform the functions described herein. Examples of a general purpose processor include, but are not limited to, a microprocessor, any conventional processor, controller, microcontroller, or state machine. In some examples, the processor may be implemented using a combination of devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration).

[0201] The functions described in this disclosure may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. Instructions or codes may be stored or transmitted to a computer-readable medium to implement the functions. Other examples for implementing the functions disclosed herein are also within the scope of this disclosure. Implementation of the functions may be via physically co-located or distributed elements (e.g., at various locations), including being distributed such that some of the functions are implemented in different physical locations.

[0202] Computer-readable media includes, but is not limited to, non-transitory computer storage media. Non-transitory storage media may be accessed by general-purpose or special-purpose computers. Examples of non-transitory storage media include, but are not limited to, random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage, and the like. Non-transitory media may be used to carry or store desired program code means (e.g., instructions and / or data structures) and may be accessed by general-purpose or special-purpose computers or general-purpose or special-purpose processors. In some examples, the software / program code may be transmitted from a remote source (e.g., a website, a server, etc.) using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, microwave, and the like. In such examples, coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, and the like, are within the definition of media. Combinations of the above examples are also within the scope of computer-readable media.

[0203] As used in this disclosure, the use of the term "or" in a list of items indicates an inclusive list. A list of items can begin with a phrase such as "at least one" or "one or more." For example, a list of at least one of A, B, or C includes A or B or C or AB (i.e., A and B) or AC or BC or ABC (i.e., A and B and C). Also, as used in this disclosure, the phrase "based on" preceding a list of conditions should not be interpreted as "based only on" the set of conditions, but rather as "based at least in part on" the set of conditions. For example, a result described as "based on condition A" can be based on both condition A and condition B without departing from the scope of this disclosure.

[0204] As used herein, the terms "comprise", "include" or "contain" may be used interchangeably, have the same meaning, and should be construed as inclusive and open-ended. The terms "comprise", "include" or "contain" may be used before a list of elements to indicate that at least all of the listed elements in the list are present, but other elements not in the list may also be present. For example, if A contains B and C, then both {B,C} and {B,C,D} are within the scope of A.

[0205] The present disclosure may be practiced or may be implemented in any manner within the scope of the present disclosure, with reference to the accompanying drawings. The present disclosure describes exemplary configurations that do not represent all configurations that may be used. The term "exemplary" should not be interpreted as "preferred" or "advantageous compared to other examples," but rather as "an example, instance, or example." By reading this disclosure, including the description of the embodiments and drawings, one skilled in the art will understand that the technology disclosed herein may be implemented using alternative embodiments. One skilled in the art will understand that the embodiments, or specific features of the embodiments described herein, may be combined to arrive at yet other embodiments for implementing the technology described in this disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. 1. A method for transmitting a phase tracking reference signal (PT-RS), comprising: receiving, by a user equipment (UE), one or more messages from a base station (BS) including uplink PT-RS configuration parameters; transmitting a PT-RS signal to the BS via radio resources of a physical uplink shared channel (PUSCH) by the UE; The uplink PT-RS configuration parameters; and a PT-RS sequence generation process for generating a PT-RS sequence, the PT-RS sequence being based on a chirp signal having a frequency that varies in time according to a chirp coefficient; a PT-RS mapping process for mapping the generated PT-RS sequence to the radio resources of the PUSCH; and The method includes:

2. the uplink phase tracking reference signal (PT-RS) configuration parameters include a first parameter defining the chirp coefficient; The method of claim 1.

3. the chirp coefficient is a predetermined value; The method of claim 1.

4. receiving downlink control information (DCI) including a field having a value defining the chirp coefficient; The method of claim 1.

5. receiving a Medium Access Control (MAC) Control Element (CE) defining the chirp coefficient; The method of claim 1.

6. The one or more messages define the uplink PT-RS configuration parameters. a phase tracking reference signal (PT-RS) uplink configuration information element defining The method of claim 1.

7. the uplink phase tracking reference signal (PT-RS) configuration parameters include a frequency density parameter that defines the presence and frequency density of the PT-RS as a function of a scheduled bandwidth of the physical uplink shared channel (PUSCH); The method of claim 1.

8. the uplink phase tracking reference signal (PT-RS) configuration parameters include a parameter defining a maximum number of uplink PT-RS ports; The method of claim 1.

9. the uplink phase tracking reference signal (PT-RS) configuration parameters include a parameter indicating an uplink PT-RS boost factor per PT-RS port; The method of claim 1.

10. the uplink phase tracking reference signal (PT-RS) configuration parameters include a resource element offset parameter defining a subcarrier offset for an uplink PT-RS; The method of claim 1.

11. The uplink phase tracking reference signal (PT-RS) configuration parameters include a sample density parameter that defines a sample density of the PT-RS for a discrete frequency transform (DFT) spread orthogonal frequency division multiplexing (OFDM), pre-DFT, that defines a set of thresholds indicating a dependency between the presence of a PT-RS and a scheduled bandwidth of the physical uplink shared channel (PUSCH). The method of claim 1.

12. the uplink phase tracking reference signal (PT-RS) configuration parameters include a time density parameter that defines the presence and time density of the PT-RS as a function of a modulation and coding scheme (MCS); The method of claim 1.

13. The uplink phase tracking reference signal (PT-RS) configuration parameters include a time-density transform precoding parameter that defines a time density of the PT-RS for discrete frequency transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) at an OFDM symbol level. The method of claim 1.

14. the uplink phase tracking reference signal (PT-RS) configuration parameters include one or more parameters defining whether the uplink PT-RS is configured with a Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) waveform or a Discrete Frequency Transform Spread Orthogonal Frequency Division Multiplexing (DFT-s-OFDM) waveform; The method of claim 1.

15. The phase tracking reference signal (PT-RS) is used to compensate for oscillator phase noise. The method of claim 1.

16. The radio resource of the physical uplink shared channel (PUSCH) is associated with a cell in frequency range 2 (FR2). The method of claim 1.

17. receiving downlink control information (DCI) including an uplink grant defining the radio resources of the physical uplink shared channel (PUSCH) for transmission of an uplink transport block; The method of claim 1.

18. the downlink control information (DCI) is one of DCI format 0_0, DCI format 0_1, and DCI format 0_2; 20. The method of claim 17.

19. The method of claim 19, wherein a first density of the PT-RS signal in a frequency domain is sparser than a second density of the PT-RS signal in a time domain. The method of claim 1.

20. the phase tracking reference signal (PT-RS) sequence generation process includes generating the PT-RS sequence based on a first process when transform precoding is not enabled, and based on a second process when transform precoding is enabled; The method of claim 1.

21. the phase tracking reference signal (PT-RS) sequence generation process includes generating values ​​of the PT-RS sequence for different subcarriers onto which the PT-RS sequence is mapped; The method of claim 1.

22. the phase tracking reference signal (PT-RS) mapping process includes mapping the generated PT-RS sequence to different resource elements within the radio resources of a physical uplink shared channel (PUSCH). The method of claim 1.

23. 1. A method for receiving a phase tracking reference signal (PT-RS), comprising: receiving, by a user equipment (UE), one or more messages from a base station (BS) including downlink PT-RS configuration parameters; receiving, by the UE, a PT-RS signal from the BS via radio resources of a physical downlink shared channel (PDSCH); The downlink PT-RS configuration parameters; and a PT-RS sequence generation process for generating a PT-RS sequence, the PT-RS sequence being based on a chirp signal having a frequency that varies in time according to a chirp coefficient; a PT-RS mapping process for mapping the generated PT-RS sequence to the radio resources of the PDSCH; and The method includes:

24. the downlink phase tracking reference signal (PT-RS) configuration parameters include a first parameter defining the chirp coefficient; 24. The method of claim 23.

25. the chirp coefficient is a predetermined value; 24. The method of claim 23.

26. receiving downlink control information (DCI) including a field having a value defining the chirp coefficient; 24. The method of claim 23.

27. receiving a Medium Access Control (MAC) Control Element (CE) defining the chirp coefficient; 24. The method of claim 23.

28. the one or more messages include a Phase Tracking Reference Signal (PT-RS) downlink configuration information element that defines the downlink PT-RS configuration parameters.

24. The method of claim 23.

29. the downlink phase tracking reference signal (PT-RS) configuration parameters include an energy per resource element (EPRE) ratio parameter that defines an EPRE ratio between the PT-RS and the physical downlink shared channel (PDSCH); 24. The method of claim 23.

30. the downlink phase tracking reference signal (PT-RS) configuration parameters include a frequency density parameter that defines the presence and frequency density of the PT-RS as a function of a scheduled bandwidth of the physical downlink shared channel (PDSCH); 24. The method of claim 23.

31. the downlink phase tracking reference signal (PT-RS) configuration parameters include a parameter indicating a maximum number of downlink PT-RS ports; 24. The method of claim 23.

32. the downlink phase tracking reference signal (PT-RS) configuration parameters include a resource element offset parameter indicating a subcarrier offset for a downlink PT-RS; 24. The method of claim 23.

33. the downlink phase tracking reference signal (PT-RS) configuration parameters include a time density parameter that defines the presence and time density of downlink PT-RS as a function of MCS; 24. The method of claim 23.

34. and compensating for oscillator phase noise based on the received phase tracking reference signal (PT-RS) signal.

24. The method of claim 23.

35. The radio resource of the physical downlink shared channel (PDSCH) is associated with a cell in frequency range 2 (FR2).

24. The method of claim 23.

36. Based on the received phase tracking reference signal (PT-RS) signal, Time and frequency tracking; an estimate of the delay spread; and estimating Doppler spread.

24. The method of claim 23.

37. receiving downlink control information (DCI) including a downlink assignment defining the radio resources of the Physical Downlink Shared Channel (PDSCH) for reception of a downlink transport block; 24. The method of claim 23.

38. the downlink control information (DCI) is one of DCI format 1_0, DCI format 1_1, and DCI format 1_2; 38. The method of claim 37.

39. The method of claim 39, wherein a first density of the PT-RS signal in a frequency domain is sparser than a second density of the PT-RS signal in a time domain.

24. The method of claim 23.

40. the phase tracking reference signal (PT-RS) sequence generation process includes generating values ​​of the PT-RS sequence for different subcarriers onto which the PT-RS sequence is mapped; 24. The method of claim 23.

41. the phase tracking reference signal (PT-RS) mapping process includes mapping the generated PT-RS sequence to different resource elements within the radio resources of a physical downlink shared channel (PDSCH).

24. The method of claim 23.

42. 1. A method for transmitting a phase tracking reference signal (PT-RS), comprising: receiving, by a first user equipment (UE) from a base station, one or more messages including sidelink PT-RS configuration parameters; transmitting a PT-RS signal to a second UE via radio resources of a physical sidelink shared channel (PSSCH), by the first UE; Sidelink PT-RS configuration parameters; and a PT-RS sequence generation process for generating a PT-RS sequence, the PT-RS sequence being based on a chirp signal having a frequency that varies in time according to a chirp coefficient; a PT-RS mapping process for mapping the generated PT-RS sequence to the radio resources of the PSSCH; and The method includes:

43. the sidelink phase tracking reference signal (PT-RS) configuration parameters include a first parameter defining the chirp coefficient.

43. The method of claim 42.

44. the chirp coefficient is a predetermined value; 43. The method of claim 42.

45. receiving downlink control information including a field having a value defining the chirp coefficient; 43. The method of claim 42.

46. receiving a medium access control (MAC) control element (CE) indicating the chirp coefficient; 43. The method of claim 42.

47. the one or more messages include a Phase Tracking Reference Signal (PT-RS) sidelink configuration information element that defines the sidelink PT-RS configuration parameters.

43. The method of claim 42.

48. the sidelink phase tracking reference signal (PT-RS) configuration parameters include a frequency density parameter defining the presence and frequency density of the PT-RS as a function of a scheduled bandwidth of the physical sidelink shared channel (PSSCH).

43. The method of claim 42.

49. the sidelink phase tracking reference signal (PT-RS) configuration parameters include a resource element offset parameter indicating a subcarrier offset of a sidelink PT-RS.

43. The method of claim 42.

50. The sidelink phase tracking reference signal (PT-RS) configuration parameters include a time-density parameter that defines the presence and time-density of sidelink PT-RS as a function of MCS.

43. The method of claim 42.

51. The PT-RS signal is used to compensate for oscillator phase noise by the second user equipment (UE).

43. The method of claim 42.

52. The phase tracking reference signal (PT-RS) Time and frequency tracking; an estimate of the delay spread; and an estimation of Doppler spread; 43. The method of claim 42.

53. receiving downlink control information (DCI) including sidelink scheduling parameters indicating the radio resources of the Physical Sidelink Shared Channel (PSSCH) for transmission of a sidelink transport block.

43. The method of claim 42.

54. The downlink control information (DCI) is one of DCI format 3_0 and DCI format 3_1.

54. The method of claim 53.

55. The method according to claim 55, wherein a first density of the PT-RS signal in a frequency domain is sparser than a second density of the PT-RS signal in a time domain.

43. The method of claim 42.

56. the phase tracking reference signal (PT-RS) sequence generation process includes generating values ​​of the PT-RS sequence for different subcarriers onto which the PT-RS sequence is mapped; 43. The method of claim 42.

57. the phase tracking reference signal (PT-RS) mapping process comprises mapping the generated PT-RS sequence to different resource elements within the radio resources of a physical sidelink shared channel (PSSCH).

43. The method of claim 42.

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