Method and apparatus for transmitting sidelink positioning reference signal in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a communication system includes receiving an SL grant for SL transmission from a base station, in the presence of an SL positioning reference signal (SL-PRS) for transmission for a selected destination, identifying a first transport block size (TBS) including the SL-PRS based on the SL grant, and transmitting the SL-PRS on the basis of the SL grant in a case where all data in a logical channel having a higher priority than the logical channel of the SL-PRS is allocated with a resource of the SL grant.

Description

Technical Field

[0001] This disclosure generally relates to wireless communication systems, and more specifically, to methods and apparatus for transmitting side-link positioning reference signals (SL-PRS) in wireless communication systems. Background Technology

[0002] Fifth-generation (5G) mobile communication technology defines wide bandwidths to enable high transmission rates and new services, and can be implemented not only in sub-6 GHz bands such as 3.5 GHz, but also in bands above 6 GHz, including the 28 GHz and 39 GHz bands, known as millimeter wave (mmWave) bands. Furthermore, sixth-generation (6G) mobile communication technology, known as Super 5G systems, has been considered for implementation in terahertz (THz) bands (e.g., the 95 GHz to 3 THz band), aiming to achieve transmission rates fifty times faster than 5G and ultra-low latency one-tenth that of 5G.

[0003] Since the initial stages of 5G mobile communication technology, in order to support services and meet the performance requirements associated with enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC), and massive machine-type communication (mMTC), standardization is underway for the following: beamforming and massive multiple-input multiple-output (MIMO) for mitigating radio wave path loss and increasing radio wave transmission distance in mmWave; parameter sets for dynamic operation (e.g., operating multiple subcarrier spacings) for effectively utilizing mmWave resources and time slot formats; initial access technologies for supporting multi-beam transmission and broadband; definition and operation of bandwidth portions (BWP); new channel coding methods such as low-density parity-check (LDPC) codes for high-capacity data transmission and polar codes for highly reliable transmission of control information; layer 2 (L2) preprocessing; and network slicing for providing dedicated networks tailored to specific services.

[0004] Given the services that 5G mobile communication technology will support, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology, and physical layer standardization already exists for technologies such as: Vehicle-to-Everything (V2X), used to assist autonomous vehicles in determining driving based on information sent by the vehicle about its location and status, and to enhance user convenience; New Radio Unlicensed (NR-U), designed to comply with the various regulatory requirements related to unlicensed frequency bands; NR UE power saving; Non-Terrestrial Network (NTN), which is UE-satellite direct communication, used to ensure coverage in areas where communication with terrestrial networks is unavailable; and positioning.

[0005] Standardization is also underway in the areas of wireless interface architecture / protocols for technologies such as: Industrial Internet of Things (IIoT) for supporting new services through interoperability and convergence with other industries; Integrated Access and Backhaul (IAB) for providing nodes for network service area extension by supporting wireless backhaul and access links in an integrated manner; Mobility enhancements including conditional handover and Dual Active Protocol Stack (DAPS) handover; and Two-Step Random Access for simplifying the NR two-step random access channel (2-step RACH) process. Standardization is also underway in the areas of system architecture / services for: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies; and Mobile Edge Computing (MEC) for UE location-based reception services.

[0006] If this 5G mobile communication system is commercialized, the already exponentially growing number of connected devices will connect to the communication network, and therefore, enhanced functionality and performance of the 5G mobile communication system, as well as integrated operation of connected devices, are expected to be necessary. To this end, new research related to extended reality (XR) has been arranged to effectively support augmented reality (AR), virtual reality (VR), mixed reality (MR), etc., by leveraging artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication, while also improving 5G performance and reducing complexity.

[0007] This development of 5G mobile communication systems will not only serve as the foundation for developing new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, full-dimensional MIMO (FD-MIMO), multi-antenna transmission technologies such as array antennas and massive MIMO, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS), but will also serve as the foundation for developing full-duplex technologies to improve the frequency efficiency of 6G mobile communication technology and improve system networks, AI-based communication technologies to achieve system optimization and internalize end-to-end AI support functions by leveraging satellites and AI from the design stage, and next-generation distributed computing technologies to achieve services with complexity exceeding the operational capabilities of UEs by utilizing ultra-high-performance communication and computing resources. Summary of the Invention

[0008] [Technical Issues]

[0009] This disclosure has been made to address at least the aforementioned problems and / or disadvantages, and to provide at least the following advantages.

[0010] Therefore, one aspect of this disclosure is to provide a method and apparatus for transmitting SL-PRS in a wireless communication system, so as to more effectively provide the transmission and measurement of SL-PRS used in sidelink positioning, as well as the selection and allocation of sidelink transmission resources.

[0011] One aspect of this disclosure is to provide a method and apparatus for transmitting an SL-PRS, the SL-PRS being transmitted by at least two UEs, which may be within and / or outside the communication range of a base station, to perform a sidechain positioning process in a communication system.

[0012] [Solution to the problem]

[0013] According to one aspect of this disclosure, a method for SL communication performed by a terminal includes: receiving an SL grant for SL transmission from a base station; identifying a first transport block size (TBS) including the SL-PRS based on the SL grant if an SL-PRS for transmission to a selected destination exists; and transmitting the SL-PRS based on the SL grant if all data in a logical channel having a higher priority than the logical channel of the SL-PRS is allocated resources with the SL grant.

[0014] According to one aspect of this disclosure, a terminal for SL communication includes: a transceiver; and a controller coupled to the transceiver and configured to receive an SL grant for SL transmission from a base station, identify a first TBS including the SL-PRS based on the SL grant if an SL-PRS for transmission to a selected destination exists, and transmit the SL-PRS based on the SL grant if all data in a logical channel having a higher priority than the logical channel of the SL-PRS is allocated resources of the SL grant.

[0015] [Beneficial effects of the invention]

[0016] One aspect of this disclosure is to provide a terminal that, when transmitting an SL-PRS, performs a sidelink positioning process by comparing the priority of the SL-PRS with the priority of the SL data to effectively select resources for transmitting the SL-PRS and allocate resources for the SL data accordingly. Attached Figure Description

[0017] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 The structure of a next-generation mobile communication system according to an embodiment is shown;

[0019] Figure 2The user plane radio protocol structure of a next-generation mobile communication system according to an embodiment is shown;

[0020] Figure 3 The control plane radio protocol structure of a next-generation mobile communication system according to an embodiment is shown;

[0021] Figure 4 The structure of a base station in a wireless communication system according to an embodiment is shown;

[0022] Figure 5 The structure of a UE in a wireless communication system according to an embodiment is shown;

[0023] Figure 6A An example of a scenario of SL communication in a wireless communication system according to an embodiment is shown;

[0024] Figure 6B An example of a scenario of SL communication in a wireless communication system according to an embodiment is shown;

[0025] Figure 6C An example of a scenario of SL communication in a wireless communication system according to an embodiment is shown;

[0026] Figure 6D An example of a scenario of SL communication in a wireless communication system according to an embodiment is shown;

[0027] Figure 7A An example of a transmission scheme for SL communication in a wireless communication system according to an embodiment is shown;

[0028] Figure 7B An example of a transmission scheme for SL communication in a wireless communication system according to an embodiment is shown;

[0029] Figure 8 An example of an SL resource pool in a wireless communication system according to an embodiment is shown;

[0030] Figure 9 An example of a signal flow for allocating transmission resources of a SL in a wireless communication system, according to an embodiment, is shown;

[0031] Figure 10 Another example of a signal flow for allocating transmission resources of a SL in a wireless communication system, according to an embodiment, is shown;

[0032] Figure 11A An example of a channel structure for a time slot used for SL communication in a wireless communication system according to an embodiment is shown;

[0033] Figure 11B An example of a channel structure for time slots used for SL communication and SL-PRS in a wireless communication system according to an embodiment is shown;

[0034] Figure 12 The process of transmitting SL data by a UE in a wireless communication system according to an embodiment is illustrated;

[0035] Figure 13 The process of a UE transmitting SL data and SL-PRS in a wireless communication system according to an embodiment is illustrated.

[0036] Figure 14 The process of a UE transmitting SL data and SL-PRS in a wireless communication system according to an embodiment is illustrated; and

[0037] Figure 15 The process of a UE transmitting SL-PRS in a wireless communication system according to various embodiments of the present disclosure is illustrated. Detailed Implementation

[0038] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the drawings, the same or similar elements are preferably represented by the same or similar reference numerals. For clarity and brevity, detailed descriptions of known functions or configurations that might obscure the subject matter of this disclosure will be omitted.

[0039] The terms described below are defined with reference to the functionality in this disclosure and may vary depending on the intent or practice of the user and provider. Therefore, they should be defined based on the entire contents of this specification.

[0040] Some elements may be exaggerated, omitted, or shown schematically. The sizes of the elements do not perfectly reflect their actual sizes. In each figure, the same or equivalent elements are assigned the same reference numerals.

[0041] This disclosure is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose this disclosure and to inform those skilled in the art of its scope. Throughout this specification, the same or similar reference numerals denote the same or similar elements.

[0042] In this document, elements included in the present disclosure are represented in a singular or plural form according to the detailed embodiments presented. However, for ease of description, the singular or plural form is suitably chosen for the presented situation, and the present disclosure is not limited to elements represented in a singular or plural form. Thus, an element represented in a plural form may also include a single element, or an element represented in a singular form may include multiple elements.

[0043] The following description is primarily directed to the NR as Radio Access Network (RAN) and the Packet Core as Core Network (CN) in the 5G mobile communication standard defined by the 3rd Generation Partnership Project (3GPP), the mobile communications standardization group. However, based on the assessment of those skilled in the art, this disclosure can be applied, with some modifications, to other communication systems with similar backgrounds without significantly departing from the scope of this disclosure.

[0044] For ease of description, this document may use some of the terms and names defined in the 3GPP standards. However, this disclosure is not limited to these terms and names and may be applied similarly to systems conforming to other standards.

[0045] For ease of description, terms used herein to identify access nodes and to refer to network entities, messages, interfaces between network entities, various identification information, etc., are used illustratively. Therefore, this disclosure is not limited to the terminology used herein, and other terms that refer to entities with equivalent technical meanings may be used.

[0046] Here, a base station is an entity that allocates resources to a terminal, and can be at least one of a gNode B, eNode B, Node B, base station (BS), radio access unit, base station controller, and a node on a network. A terminal can include a user equipment (UE), mobile station (MS), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions. In this disclosure, downlink (DL) refers to a radio link through which a base station transmits signals to a terminal, and uplink (UL) refers to a radio link through which a terminal transmits signals to a base station.

[0047] UE can refer to a vehicle supporting vehicle-to-vehicle (V2V) communication, a pedestrian mobile phone (e.g., a smartphone), or a vehicle supporting vehicle-to-pedestrian (V2P) communication, vehicle-to-network (V2N) communication, or vehicle-to-infrastructure (V2I) communication. UE can also refer to a roadside unit (RSU) equipped with UE functionality, an RSU equipped with base station functionality, or an RSU equipped with some BS functionality and some UE functionality. Additionally, UE can refer to a UE that supports proximity services (ProSe) and sidelink positioning procedures.

[0048] In this paper, the base station may support both SL and general cellular communication, or it may support only SL. In this case, the base station may be a 5G base station (gNB), a 4G base station (eNB), or an RSU.

[0049] Figure 1 The structure of a next-generation mobile communication system according to an embodiment is shown.

[0050] refer to Figure 1The radio access network of a next-generation mobile communication system (hereinafter, NR or 5G) may include a next-generation base station (New Radio (NR) Node B, NR gNB, gNB or NR base station) 120 and an NR CN 110. User terminals (NR UE or NR terminal) 150 may access external networks via NR gNB 120 and NR CN 110.

[0051] The NR gNB 120 can connect to the NR UE 150 via radio channels and provides superior service compared to the eNB 140. In next-generation mobile communication systems, since all user services are served through a shared channel, a device is needed to collect state information (such as the UE's buffer state, available transmit power state, and channel state) and perform scheduling accordingly, and the NR gNB 120 can serve as this device. Typically, one NR gNB 120 can control multiple cells. To achieve ultra-high-speed data transmission exceeding LTE, a bandwidth wider than the maximum bandwidth of LTE can be used, and an Orthogonal Frequency Division Multiplexing (OFDM) scheme can be employed as the radio access technology, which can also be integrated with beamforming technology. Furthermore, an Adaptive Modulation and Coding (AMC) scheme can be used to determine the modulation scheme and channel coding rate based on the UE's channel state. The NR CN 110 can perform functions such as mobility support and Quality of Service (QoS) configuration. The NR CN 110 is responsible for various control functions and UE mobility management functions and can connect to multiple base stations. The next-generation mobile communication system can interoperate with existing LTE systems, and the NR CN 110 can connect to the Mobility Management Entity (MME) 130 via a network interface. The MME 130 can connect to the eNB 140.

[0052] Figure 2 The user plane radio protocol structure of a next-generation mobile communication system according to an embodiment is shown.

[0053] refer to Figure 2In UE 210, the user plane radio protocol of the next-generation mobile communication system can consist of Serving Data Adaptation Protocol (SDAP) 211, Packet Data Convergence Protocol (PDCP) 212, Radio Link Control (RLC) 213, Media Access Control (MAC) 214, and / or Physical (PHY) layer 215. In gNB 220, the user plane radio protocol of the next-generation mobile communication system can consist of SDAP 221, PDCP 222, RLC 223, MAC 224, and / or PHY 225. For example, in UE 210, the user plane radio protocol of the next-generation mobile communication system may include SDAP 211, PDCP 212, RLC 213, MAC 214, and / or PHY 215.

[0054] The main functions of SDAP 211 or 221 may include the following.

[0055] Mapping between QoS streams and data radio bearers

[0056] - Mark the QoS Flow ID (QFI) in both DL and UL packets.

[0057] The main functions of PDCP 212 or 222 may include the following.

[0058] - Data transmission (user plane or control plane)

[0059] - Maintenance of PDCP serial number (SN)

[0060] - Header compression and decompression using the Robust Header Compression (ROHC) protocol

[0061] - Header compression and decompression using the Ethernet Header Compression (EHC) protocol

[0062] - UL PDCP Service Data Unit (SDU) Compression and Decompression: Uplink Data Compression (UDC) Based Only on DEFLATE

[0063] - Encryption and decryption

[0064] -Integrity protection and integrity verification)

[0065] - SDU discarding based on timer

[0066] - For split bearers, routing

[0067] -copy

[0068] - Reordering and sequential delivery

[0069] -unordered delivery

[0070] -Duplicate discarding

[0071] The main functions of RLC 213 or 223 may include the following functions.

[0072] -Transmission of upper-layer PDUs

[0073] - The sequence number is independent of the sequence number in PDCP (Unacknowledged Mode (UM) and Acknowledged Mode (AM)).

[0074] - Error correction via Automatic Repeat Request (ARQ) (AM only)

[0075] - Segmentation (AM and UM) and resegmentation (AM only) of RLC SDU

[0076] - SDU reorganization (AM and UM)

[0077] -Duplicate detection (AM only)

[0078] -RLC SDU discard (AM and UM)

[0079] -RLC Reconstruction

[0080] Protocol error detection (AM only)

[0081] The main functions of the MAC 214 or 224 may include the following.

[0082] Mapping between logical channels and transport channels

[0083] - Multiplex MAC SDUs from one or more logical channels onto a transport block (TB) to be delivered to the physical layer on the transport channel.

[0084] - Demultiplex the TB delivered by the MAC SDU from the physical layer on the transport channel to one or different logical channels.

[0085] - Scheduling Information Report

[0086] Error correction via Hybrid Automatic Repeat Request (HARQ)

[0087] -Logical channel prioritization

[0088] Priority handling between overlapping resources of a UE

[0089] PHY layer 215 or 225 can perform channel coding and modulation of upper-layer data to generate OFDM symbols, and can convert OFDM symbols into radio frequency (RF) signals, which are then transmitted through an antenna. PHY layer 215 or 225 can perform demodulation and channel decoding on the received OFDM symbols, and then transmit the OFDM symbols to the upper layer.

[0090] Figure 3 The control plane radio protocol structure of a next-generation mobile communication system according to an embodiment is shown.

[0091] refer to Figure 3 The control plane radio protocol of the next-generation mobile communication system can be configured by Radio Resource Control (RRC) 311, PDCP 312, RLC 313, MAC 314 and / or PHY 315 in UE 310, and can be configured by RRC 321, PDCP 322, RLC 323, MAC 324 and / or PHY 325 in base station 320.

[0092] The functions of RRC 311 and 321 may include the following functions.

[0093] - Broadcasting of system information (related to Access Layer (AS) and Non-Access Layer (NAS))

[0094] - Paging (initiated by 5G Core (5GC) or Next Generation (NG) RAN)

[0095] - Establishment and management of RRC connections between UE and NG-RAN, and addition, modification and release of carrier aggregation and dual connections between NRs or between Evolved Universal Terrestrial Radio Access (E-UTRA) and NR (Establishment, maintenance and release of RRC connections between UE and NG-RAN, including: addition, modification and release of carrier aggregation; addition, modification and release of dual connections in NR or between E-UTRA and NR)

[0096] -Includes security features for key management

[0097] - Establishment, configuration, maintenance, and release of signaling radio bearers (SRBs) and data radio bearers (DRBs)

[0098] -UE mobility support (mobility functions include: handover and context delivery; UE cell selection and reselection and control of cell selection and reselection; inter-RAT mobility)

[0099] -QoS management function

[0100] - UE measurement reports and control of reports

[0101] - Radio link failure detection and recovery (Detection and recovery of radio link failures)

[0102] -NAS message transmission (NAS messages transmitted from UE to NAS / from NAS to UE)

[0103] The main functions of PDCP 312 and 322, RLC 313 and 323, MAC 314 and 324 and / or PHY 315 and 325 can be followed Figure 2 Examples.

[0104] Figure 4 The structure of a base station according to an embodiment is shown.

[0105] refer to Figure 4 The base station includes a transceiver 405, a controller 410, and a memory 415, which can operate according to the communication method described above. Network devices may also correspond to the structure of the base station. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than those described above. For instance, the base station may include a transceiver 405 and a controller 410. The transceiver 405, controller 410, and memory 415 may be implemented as a single chip.

[0106] Transceiver 405 refers to a base station receiver and base station transmitter as a whole, and can send / receive signals with the UE, other base stations, or other network devices. Signals may include control information and data. Transceiver 405 can send, for example, system information, synchronization signals, or reference signals to the UE. For this purpose, transceiver 405 may include an RF transmitter configured to up-convert and amplify the frequency of the transmitted signal, an RF receiver configured to perform low-noise amplification and down-convert the frequency of the received signal, etc. However, the components of transceiver 405 are not limited to RF transmitters and RF receivers. Transceiver 405 may include wired / wireless transceivers and may include various components for sending / receiving signals. Transceiver 405 can receive signals through a communication channel (e.g., a radio channel), output them to controller 410, and transmit signals output from controller 410 through a communication channel. Transceiver 405 can receive communication signals, output them to a processor, and transmit signals output from the processor to the UE, other base stations, or other network entities via a wired / wireless network.

[0107] The memory 415 can store programs and data required for the operation of the base station. The memory 415 can store control information or data included in signals acquired by the base station. The memory 415 can include storage media or combinations of storage media such as read-only memory (ROM), random access memory (RAM), hard disk, CD-ROM, and DVD. The memory 415 can store at least one of information transmitted / received by transceiver 405 and information generated by controller 410.

[0108] As used herein, controller 410 may be defined as a circuit, an application-specific integrated circuit (ASIC), or at least one processor. The processor may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper-layer applications such as applications. Controller 410 may control the overall operation of the base station according to this disclosure. For example, controller 410 may control the signal flow between various blocks to perform operations according to the flowchart described above.

[0109] Figure 5 The structure of the UE according to an embodiment is shown.

[0110] refer to Figure 5 The UE includes a transceiver 505, a controller 510, and a memory 515. The transceiver 505, controller 510, and memory 515 can operate according to the communication method described above for the UE. The components of the UE are not limited to the examples described above. For example, the UE may include more or fewer components than those described above. For example, the UE may include a transceiver 505 and a controller 510. The transceiver 505, controller 510, and memory 515 may be implemented as a single chip.

[0111] Transceiver 505 refers to a UE receiver and UE transmitter as a whole, capable of transmitting / receiving signals with a base station, other UEs, or network entities. Signals may include control information and data. Transceiver 505 can receive, for example, system information, synchronization signals, or reference signals from the base station. For this purpose, transceiver 505 may include an RF transmitter configured to up-convert and amplify the frequency of transmitted signals, an RF receiver configured to perform low-noise amplification and down-convert the frequency of received signals, etc. However, the components of transceiver 505 are not limited to RF transmitters and RF receivers. Furthermore, transceiver 505 may include wired / wireless transceivers and may include various components for transmitting / receiving signals. Transceiver 505 can receive signals via a radio channel, output them to controller 510, and transmit signals output from controller 510 via a radio channel. Transceiver 505 can receive communication signals, output them to a processor, and transmit signals output from the processor to network entities via a wired / wireless network.

[0112] The memory 515 can store programs and data required for the operation of the UE. The memory 515 can store control information or data included in signals acquired by the UE. The memory 515 can include storage media such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media.

[0113] As used herein, controller 510 may be defined as a circuit, an application-specific integrated circuit (ASIC), or at least one processor. The processor may include a CP (Content Processor) that performs control for communication and an AP (Application Processor) that controls upper layers such as applications. Controller 510 may control the overall operation of the UE according to embodiments of this disclosure. For example, controller 510 may control the signal flow between various blocks to perform operations according to the flowchart described above.

[0114] Figure 6A An example scenario of SL communication in a wireless communication system according to an embodiment is shown. Figure 6B An example scenario of SL communication in a wireless communication system according to an embodiment is shown. Figure 6C An example scenario of SL communication in a wireless communication system according to an embodiment is shown. Figure 6D An example scenario of SL communication in a wireless communication system according to an embodiment is shown.

[0115] Figure 6A The diagram illustrates a scenario where SL UEs 620 and 625 are within the coverage area (IC) of base station 600, specifically within its coverage area 610. SL UEs 620 and 625 can receive data and control information from the base station via DL, or transmit data and control information to the base station via UL. In this case, the data and control information can be for SL communication, or for general cellular communication other than SL communication. Figure 6A The SL UEs 620 and 625 can send and receive data and control information for SL communication via SL.

[0116] Figure 6B The diagram illustrates a partial coverage area (PC) scenario, where the first UE 620 in the SL UE is located within the coverage area 610 of base station 600, while the second UE 625 is located outside the coverage area 610 of base station 600. The first UE 620, located within the coverage area 610 of base station 600, can receive data and control information from the base station via DL, or transmit data and control information to the base station via UL. The second UE 625, located outside the coverage area of ​​base station 600, cannot directly receive data and control information from the base station via DL, nor can it directly transmit data and control information to the base station via UL. The second UE 625 can transmit and receive data and control information for SL communication from the first UE 620 via SL.

[0117] Figure 6CThis is an example when the SL UE (e.g., the first UE 620 and the second UE 625) is outside the coverage area 610 of the base station 600 (out-of-coverage (OOC)). Therefore, the first UE 620 and the second UE 625 cannot receive data and control information from the base station via the DL, and cannot send data and control information to the base station via the UL. The first UE 620 and the second UE 625 can send and receive data and control information for SL communication via the SL.

[0118] Figure 6D Inter-cell SL communication is performed when a first UE 620 and a second UE 625 performing SL communication are connected (e.g., in an RRC connected state) to or reside (e.g., in an RRC disconnected state, i.e., an RRC idle state or an inactive state) at different base stations (e.g., a first base station 600 and a second base station 605). In this case, the first UE 620 can be an SL transmitting UE, and the second UE 625 can be an SL receiving UE. Alternatively, the first UE 620 can be an SL receiving UE, and the second UE 625 can be an SL transmitting UE. The first UE 620 can receive a System Information Block (SIB) for SL from the base station 600 to which the first UE 620 is connected (or to which the first UE 620 resides). The second UE 625 can receive an SIB for SL from the base station 605 to which the second UE 625 is connected (or to which the second UE 625 resides). In this case, the information of the SIB for SL received by the first UE 620 and the information of the SIB for SL received by the second UE 625 can be different from each other. Therefore, in order to perform SL communication between UEs located in different cells, unified information may be required, or other assumptions and interpretation methods may be needed.

[0119] exist Figures 6A to 6D For ease of description, an SL system comprising two UEs (e.g., first UE 620 and second UE 625) is illustrated, but this disclosure is not limited thereto and can be applied to SL systems involving three or more UEs. The UL and DL interfaces between the base station 600 and the SL UEs can be referred to as Uu interfaces, and the SL interfaces between the SL UEs can be referred to as PC5 interfaces. Additionally, SL UEs located outside the coverage area (OOC) (i.e., SL UEs located where the base station 600 and the Uu interface are not connected) can indirectly receive data and control information from the base station via relays of SL UEs located within the coverage area (IC) where the base station and the Uu interface are connected. Here, the UL or DL ​​and Uu interfaces can be used interchangeably, and the SL and PC5 interfaces can be used interchangeably.

[0120] Figure 7AAn example of a transmission scheme for SL communication in a wireless communication system according to an embodiment is shown. Figure 7B An example of a transmission scheme for SL communication in a wireless communication system according to an embodiment is shown. Figure 7A The unicast scheme is shown, and Figure 7B The multicast scheme is shown.

[0121] like Figure 7A As shown, the sending UE 700 and receiving UE 705 can perform one-to-one communication. Figure 7A The transmission scheme used in this method can be called unicast communication. For example... Figure 7B As shown, sending to UE 730 or 745 and receiving from UEs 735, 740, 750, 755, and 760 can perform one-to-many communication. For example... Figure 7B The transmission scheme in this context can be referred to as multicast or multi-cast.

[0122] exist Figure 7B In this configuration, the first UE 730, the second UE 735, and the third UE 740 can form a group and perform multicast communication, and the fourth UE 745, the fifth UE 750, the sixth UE 755, and the seventh UE 760 can form another group and perform multicast communication. A UE can perform multicast communication within its own group and can also perform unicast, multicast, or broadcast communication with at least one other UE belonging to a different group. Figure 7B Two groups are shown in the figure, but this disclosure is not limited to these and can be applied to more groups.

[0123] exist Figure 7A or Figure 7B In this context, the SL UE can perform broadcast communication, which refers to a scheme where all SL UEs receive data and control information sent by the SL sending UE via the SL. For example, if... Figure 7B If the first UE 730 is the transmitting UE, then the other UEs 735, 740, 745, 750, 755 and 760 can receive the data and control information transmitted by the first UE 730.

[0124] The above-mentioned SL unicast communication, multicast communication and broadcast communication can be supported in IC scenarios, partial coverage scenarios or OOC scenarios.

[0125] Figure 8 An example of an SL resource pool in a wireless communication system according to an embodiment is shown. A resource pool can be defined as a set of resources in the time and frequency domains used for SL transmission and reception.

[0126] Within the resource pool, the resource allocation unit (resource granularity) on the time axis can be one or more OFDM symbols. Conversely, the resource granularity on the frequency axis can be one or more physical resource blocks (PRBs).

[0127] When allocating resource pools in the time and frequency domains, the region including shaded resources indicates the region configured as a resource pool in both time and frequency. This disclosure provides a description of resource pool allocation when it is discontinuous in time, but this disclosure is not limited thereto and can also be applied to resource pool allocation when it is continuous in time. This document provides a description of resource pool allocation when it is continuous in frequency, but this disclosure is not limited thereto and can also be applied to resource pool allocation when it is discontinuous in frequency.

[0128] refer to Figure 8 The time domain 800 of the configured resource pool indicates when resources are allocated discontinuously in the time domain. In the time domain 800 of the resource pool, the resource granularity of the time axis can be a time slot. Specifically, a time slot comprising 14 OFDM symbols can be the basic resource granularity of the time axis. Referring to the time domain 800 of the configured resource pool, shaded time slots indicate time slots allocated as resource pools in time, and system information can be used to indicate time slots allocated as resource pools in time. For example, time-domain resource pool configuration information in the SIB can be used to indicate time slots allocated as resource pools in time. Specifically, at least one time slot configured as a resource pool in time can be indicated via a bitmap. (See reference...) Figure 8 Physical time slot 800, belonging to a non-contiguous resource pool on the time axis, can be mapped to logical time slot 825. Typically, a set of time slots belonging to a resource pool used for Physical Side Link Shared Channel (PSSCH) can be represented as (t0, t1, ..., t...). i ,…, t Tmax ).

[0129] exist Figure 8 In the configuration, the frequency domain 805 of the resource pool indicates when resources are allocated consecutively in the frequency domain. Within the frequency domain 805 of the resource pool, the resource granularity along the frequency axis can be a subchannel 810. Specifically, a single subchannel 810 comprising one or more resource blocks (RBs) can be defined as a basic resource granularity in the frequency domain. That is, a subchannel 810 can be defined as an integer multiple of RBs. The subchannel size (sizeSubchannel) can include five consecutive PRBs. However, this disclosure is not limited to this, and the subchannel size can be configured differently. Furthermore, a single subchannel typically comprises consecutive PRBs, but the PRBs are not necessarily consecutive. Subchannel 810 can be a basic resource granularity for the PSSCH. Additionally, subchannels for the Physical Side Link Feedback Channel (PSFCH) can be defined independently of the PSSCH.

[0130] exist Figure 8In the resource pool, the starting position of a subchannel on a frequency can be indicated by startRB-Subchannel 815. When resource allocation is performed on a frequency axis in units of subchannels 810, the frequency-based resource pool can be configured via configuration information of the RB index (startRB-Subchannel) 815 indicating where the subchannel begins, information indicating the number of RBs constituting the subchannel (sizeSubchannel) 810, and the total number of subchannels (numSubchannel). The frequency-based resource pool can also be configured via configuration information of the RB index (EndRB-Subchannel) 820 indicating where the subchannel ends. System information can be used to indicate the subchannels allocated as resource pools on a frequency. For example, at least one of startRB-Subchannel, sizeSubchannel, EndRB-SubChannel, and numSubchannel can be indicated as frequency resource pool configuration information in the SIB. When subchannels for PSFCH are defined independently of PSSCH, the subchannel configuration information for PSFCH and PSSCH can be indicated to the UE separately.

[0131] Figure 9 An example of a signal flow for allocating transmission resources of a sidelink in a wireless communication system, according to an embodiment, is shown. (Reference) Figure 9 The diagram illustrates the signal exchange between the transmitting UE 901, the receiving UE 902, and the base station 903.

[0132] The scheme by which the base station allocates transmission resources for SL communication can be referred to as Mode 1. Mode 1 is a resource allocation scheme based on scheduling by the base station. In Mode 1 resource allocation, the base station can allocate resources for SL transmission to UEs with RRC connections according to a dedicated scheduling scheme. Since the base station can manage sidelink resources, the scheduled resource allocation is advantageous for interference management and resource pool management (e.g., dynamic allocation and / or semi-persistent transmission).

[0133] refer to Figure 9In step 905, transmitting UE 901 camps on the cell and can receive SL SIB from base station 903. In step 909, receiving UE 902 can receive SL SIB from base station 903. Receiving UE 902 refers to the UE that receives data transmitted by transmitting UE 901. SL SIB can be transmitted periodically or on demand. SL SIB may include at least one of SL resource pool information for SL communication, parameter configuration information for sensing operations, information for configuring SL synchronization, or carrier information for SL communication operating at different frequencies. Although operations 907 and 909 have been described sequentially above, this is only for ease of description, and steps 907 and 909 can be performed in parallel.

[0134] In step 913, when a data service for SL communication is generated in the transmitting UE 901, the transmitting UE 901 can connect to the base station 903 via RRC. The RRC connection between the transmitting UE 901 and the base station 903 can be referred to as Uu-RRC. The Uu-RRC connection can be established before the data service of the transmitting UE 901 is generated. In mode 1, when a Uu-RRC connection is established between the base station 903 and the receiving UE 902, the transmitting UE 901 can perform transmission to the receiving UE 902 via SL. In mode 1, even when a Uu-RRC connection is not established between the base station 903 and the receiving UE 902, the transmitting UE 901 can still perform transmission to the receiving UE 902 via SL.

[0135] In step 915, the transmitting UE 901 can request transmission resources from the base station 903 for performing SL communication with the receiving UE 902. In this case, the transmitting UE 901 can request transmission resources for SL from the base station 903 using at least one of the Physical Uplink Control Channel (PUCCH), RRC messages, or MAC CE. For example, when using MAC CE, the MAC CE can be associated with a new form of Buffer Status Report (BSR) that includes at least one piece of information regarding an indicator for the BSR used for SL communication and the size of the data stored in the buffer for device-to-device (D2D) communication (or V2X communication). This MAC CE can be referred to as the SL BSR MAC CE. Alternatively, when using PUCCH, the transmitting UE 901 can request SL resources using a Scheduling Request (SR) bit transmitted via PUCCH. Additionally, when using RRC, the sending UE 901 can transmit information about receiving UE 902 to the base station via Uu-RRC, as well as the frequency of sending and receiving various types of SL communications, including SL discovery, SL data communication, SL relay communication, and sidelink positioning procedures, and can include at least one of the following information via the same or different RRC messages.

[0136] The frequency to be used for receiving in SL communication

[0137] Frequency to be used for transmission in SL communication

[0138] Types of SL data sent in SL communication

[0139] The period and size of SL data sent in SL communication

[0140] Information about the destination UE (destination UE ID, UE capabilities, discontinuous reception (DRX) information, etc.) received from the SL data transmitted in SL communication.

[0141] QoS information of SL data sent in SL communication

[0142] The casting type of SL data sent in SL communication

[0143] RLC mode of SL data sent in SL communication

[0144] In step 915, the PUCCH, MAC CE, and RRC messages can be used independently of each other, or in combination depending on the purpose. Additionally, although step 915 is described after step 913, this is for ease of description. Step 915 can also be used to send a request from UE 901 for resources to establish PC5-RRC 911 relative to the receiving UE 902, and can be performed in parallel or simultaneously with other operations.

[0145] In step 917, base station 903 may send DL control information (DCI) to transmitting UE 901 via PDCCH. That is, base station 903 may indicate to transmitting UE 901 scheduling information for SL communication with receiving UE 902. More specifically, base station 903 may allocate SL transmission resources to transmitting UE 901 according to at least one of dynamic grant (DG) scheme or configuration grant (CG) scheme.

[0146] For the DG scheme, base station 903 can allocate resources for transmitting one TB by sending a DCI to transmitting UE 901. The SL scheduling information included in the DCI may include at least one of resource pool information, parameters related to initial transmission timing and / or retransmission timing, and parameters related to the frequency allocation location information field. The DCI used for the DG scheme can be scrambled with Cyclic Redundancy Check (CRC) based on the Sidelink Radio Network Temporary Identifier (SL-RNTI) to indicate that the transmission resource allocation scheme is the DG scheme.

[0147] For the CG scheme, semi-persistent scheduling (SPS) information can be configured via Uu-RRC, and the SPS information can include SPS intervals. Based on the SPS intervals, resources for transmitting multiple TBs can be allocated periodically. In this case, base station 903 can allocate resources for multiple TBs by sending a DCI to transmitting UE 901. The SL scheduling information included in the DCI can include at least one of parameters related to the initial transmission timing and / or retransmission timing, and parameters related to the frequency allocation location information field. The initial transmission timing and / or retransmission timing and the frequency allocation location can be determined based on the transmitted DCI, and resources can be repeated at SPS intervals. The DCI used for the CG scheme can be CRC scrambled based on the scheduling radio network temporary identifier (SL-CS-RNTI) configured by the SL to indicate that the transmission resource allocation scheme is the CG scheme.

[0148] The CG scheme can be divided into Type 1 CG and Type 2 CG. For Type 2 CG, base station 903 can activate and / or deactivate resources configured by the CG via DCI. Therefore, base station 903 can instruct sending UE 901 to schedule SL communication with receiving UE 902 by sending DCI via PDCCH.

[0149] When a broadcast transmission is performed between UEs 901 and 902, in step 919, the sending UE 901 may broadcast an SCI to the receiving UE 902 via PSCCH without additional PC5-RRC configuration (step 911). In step 921, the sending UE 901 may broadcast data to the receiving UE 902 via PSSCH.

[0150] When unicast or multicast transmission is performed between UEs 901 and 902, in step 911, sending UE 901 can establish a one-to-one RRC connection to other UEs (e.g., receiving UE 902). In this case, to distinguish it from Uu-RRC, the RRC connection between UEs 901 and 902 can be called PC5-RRC. In multicast transmission schemes, PC5-RRC connections can be established individually between UEs within the group. (Refer to...) Figure 9 Although the PC5-RRC connection (step 911) is shown as an operation following the SL SIB transmission (steps 907 and 909), the PC5-RRC connection (step 911) can be performed before the SL SIB transmission or before the SCI broadcast (step 919). If an RRC connection between UEs is required, an SL PC5-RRC connection can be performed, and in step 919, the sending UE 901 can send the SCI to the receiving UE 902 via PSCCH in unicast or multicast. In this case, the multicast transmission of the SCI can be understood as a group SCI. In step 921, the sending UE 901 can send data to the receiving UE 902 via PSSCH in unicast or multicast. In mode 1, the sending UE 901 can identify the SL scheduling information included in the DCI received from the base station 903 and perform SL scheduling based on the SL scheduling information. The SCI can be divided into a first-stage SCI transmitted via PSCCH and a second-stage SCI transmitted via PSSCH, and the first-stage SCI can include at least one of the following information.

[0151] Priority

[0152] Frequency resource allocation

[0153] Time resource allocation

[0154] Resource reservation period

[0155] Demodulation Reference Signal (DMRS) mode

[0156] Second-stage SCI format

[0157] Beta_offset indicator

[0158] Number of DMRS ports

[0159] Modulation and coding schemes

[0160] Additional Modulation and Coding Scheme (MCS) Table Indicator

[0161] PSFCH Overhead Indication

[0162] Reserved

[0163] Conflict Information Recipient Flag

[0164] Priorities can be sent or configured via the upper layer and consist of 3 bits. In this case, priority value 1 can be configured as 000, priority value 2 can be configured as 001, and so on, and up to 8 priority values ​​can be configured in this way. The priority value of SL data can have the highest priority among the MAC CEs or all logical channels included in the TB scheduled by the corresponding SCI. If a MAC CE or SCI for inter-UE coordination is sent, the priority value configured by the RRC parameters can be used instead of the priority of the MAC CE. If no RRC parameters are configured, the inter-UE coordination request MAC CE can have the highest priority among the MAC CEs or all logical channels included in the TB of the UE receiving the MAC CE, and the inter-UE coordination information MAC CE sent in response to a request from a UE that has received the inter-UE coordination request MAC CE can have the same value as the priority field value corresponding to the inter-UE coordination request MAC CE. Furthermore, if the UE-to-UE coordination information MAC CE is sent based on specific conditions (e.g., if the RSRP of the resources reserved by the third UE is greater than a specific value) rather than in response to a request from another UE, the UE can randomly select a priority from values ​​of 1 to 8.

[0165] When resources are selected for multiple TBs (i.e., multiple MAC Protocol Data Units (PDUs)), the reserved interval is indicated as a single value with a fixed interval between TBs, and when resources are selected for one TB, "0" can be indicated as the interval value between TBs.

[0166] The second-stage SCI may be included in the PSSCH resource indicated in the first-stage SCI sent in step 919, and may be sent together with the data in step 921. The second-stage SCI may include at least one of the following pieces of information.

[0167] HARQ process number

[0168] New data indicator

[0169] Redundant version

[0170] Source ID

[0171] Destination ID

[0172] HARQ feedback enable / disable indicator

[0173] Projection type indicator

[0174] Channel State Information (CSI) Request

[0175] District ID

[0176] Communication range requirements

[0177] Provide / Request Indicator

[0178] Resource combination

[0179] First resource location

[0180] Reference time slot position

[0181] Resource set type

[0182] Lowest Subchannel Index

[0183] Priority

[0184] Number of sub-channels

[0185] Resource reservation period

[0186] Resource selection window location

[0187] Resource set type

[0188] Fill bits

[0189] In step 923, the receiving UE 902 may send a first HARQ feedback message to the sending UE 901 to indicate whether the data received in step 921 has been successfully demodulated / decoded. The first HARQ feedback message includes an acknowledgment (ACK) (success) or a negative ACK (NACK) (failure) message, and the receiving UE 902 may send the first HARQ feedback message to the sending UE 901 via the PSFCH.

[0190] In step 925, the transmitting UE 901 may send second HARQ feedback information to the base station 903 based on the first HARQ feedback information received from the receiving UE 902. The second HARQ feedback information may be sent to the base station via PUCCH.

[0191] In this scenario, the second HARQ feedback information may be the same as or different from the first HARQ feedback information. The second HARQ feedback information may include multiple first HARQ feedback information messages. These multiple first HARQ feedback information messages may include multiple HARQ feedback information messages received from a single receiving UE, or they may include one or more HARQ feedback information messages received from multiple UEs.

[0192] Based on the second HARQ feedback information, the base station can allocate resources for retransmission to the transmitting UE 901, allocate resources for new transmission, or stop resource allocation when there are no more transmission resources to allocate to the transmitting UE 901.

[0193] The PUCCH 925 transport resources can be determined by the DCI sent by the base station to the transmitting UE via PDCCH 917. The PSFCH 923 transport resources can be determined based on the SCI of PSCCH 919, or based on the transport resource areas in which PSSCH 921 is transmitted and received.

[0194] Figure 10 Another example of a signal flow for allocating transmission resources of a SL in a wireless communication system, according to an embodiment, is shown. Figure 10 The signal exchange between the transmitting UE 1001, the receiving UE 1002, and the base station 1003 is shown.

[0195] As described below, the scheme in which the UE directly allocates SL transmission resources via sensing in the SL can be referred to as Mode 2. Mode 2 can also be referred to as UE autonomous resource selection.

[0196] Specifically, according to Mode 2, the transmitting UE 1001 can provide SL communication information to the base station via RRC messages (e.g., SidelinkUEInformationNR). The base station 1003 can provide the SL transmit / receive resource pool for SL to the UE via system information or RRC messages (e.g., RRCReconfiguration messages or PC5 RRC messages), and the transmitting UE 1001 can select the resource pool and resources according to the determined rules.

[0197] and Figure 9 The mode described in the text, in which the base station directly participates in resource allocation, is different from mode 1. Figure 10 Mode 2, as described in the document, allows UE 1001 to autonomously select resources and send data based on resource pools previously received via system information, RRC messages, or pre-configured settings.

[0198] refer to Figure 10 In step 1007, the transmitting UE 1001, residing on 1005, can receive the SLSIB from base station 1003. In step 1009, the receiving UE 1002 can receive the SL SIB from base station 1003. The receiving UE 1002 refers to the UE that receives data transmitted by the transmitting UE 1001. The SL SIB can be transmitted periodically or on demand. In addition, the SL SIB information may include at least one of the following: SL resource pool information for SL communication, parameter configuration information for sensing operations, information for configuring SL synchronization, or carrier information for SL communication operating at different frequencies. Although operations 1007 and 1009 have been described sequentially above, this is only for ease of description, and steps 1007 and 1009 can be performed in parallel.

[0199] In the above Figure 9 In the process, base station 1003 and transmitting UE 1001 operate in RRC connection state, while... Figure 10 In this configuration, base station 1003 and transmitting UE 1001 can operate regardless of whether an RRC connection is established between base station 1003 and transmitting UE 1001 in step 1013. That is, even in idle or inactive mode 1013 without an RRC connection, base station 1003 and transmitting UE 1001 can perform SL communication based on mode 2. Even in an RRC connection state, base station 1003 can operate to allow transmitting UE 1001 to autonomously select transmission resources without directly involving resource allocation. In this case, the RRC connection between transmitting UE 1001 and base station 1003 can be referred to as Uu-RRC.

[0200] In step 1015, when a data service for SL communication is generated in the transmitting UE 1001, the transmitting UE 1001 can configure a resource pool via system information received from the base station 1003, and can directly select time-domain and frequency-domain resources in the configured resource pool via sensing.

[0201] When a broadcast transmission is performed between UEs 1001 and 1002, in step 1017, the sending UE 1001 may broadcast an SCI to the receiving UE 1002 via PSCCH without additional SL RRC configuration (step 1011). In step 1019, the sending UE 1001 may broadcast data to the receiving UE 1002 via PSSCH.

[0202] When unicast and multicast transmissions are performed between UEs 1001 and 1002, in step 1011, sending UE 1001 can establish a one-to-one RRC connection to other UEs (e.g., receiving UE 1002). In this case, to distinguish it from Uu-RRC1013, the RRC connection between UEs 1001 and 1002 can be called PC5-RRC. In the multicast transmission scheme, PC5-RRC connections are established individually between UEs within the group. Figure 10 Although the PC5-RRC connection (step 1011) is shown as an operation following the SL SIB transmission (steps 1007 and 1009), the PC5-RRC connection (step 1011) can be performed before the SL SIB transmission or before the SCI transmission (step 1017). If an RRC connection between UEs is required, an SL PC5-RRC connection can be performed, and in step 1017, the sending UE 1001 can send the SCI to the receiving UE 1002 via PSCCH in unicast or multicast. In this case, the multicast transmission of the SCI can be understood as a group SCI. In step 1019, the sending UE 1001 can send data to the receiving UE 1002 via PSSCH in unicast or multicast. In mode 2, the sending UE 1001 can directly perform SL scheduling by performing sensing and transmission resource selection. The first-stage SCI and the second-stage SCI used in steps 1017 and 1019 can be as follows: Figure 9 As shown in the example.

[0203] Additionally, when UE 1001 performs out-of-coverage (OOC) SL communication, mode 2 resource allocation can be used, and for the SL communication information available for this purpose, information pre-configured and stored in the UE can be used, or configuration information can be received from the base station via the SL relay.

[0204] In step 1021, the receiving UE 1002 can send a HARQ feedback message to the sending UE 1001 to indicate whether the data received in step 1019 has been successfully demodulated / decoded. The HARQ feedback message includes ACK (success) or NACK (failure) information, and the receiving UE 1002 can transmit the HARQ feedback message to the sending UE 1001 via PSFCH.

[0205] Figure 11A Examples of channel structures for time slots used for SL communication in wireless communication systems according to various embodiments of the present disclosure are shown. Figure 11A The physical channel mapped to the time slots used for SL communication is shown.

[0206] refer to Figure 11A Automatic gain control (AGC) 1105, which can be used to receive the UE, is mapped to the first symbol of time slot 1100. Then, PSCCH 1110, PSSCH 1115, GUARD 1120, AGC 1125 for PSFCH, PSFCH 1130 and GUARD 1135 can be mapped sequentially.

[0207] Before transmitting the PSCCH in time slot 1100, the transmitting UE may transmit a signal for AGC in one or more symbols having the same information as the symbol transmitting PSCCH 1110. AGC symbol 1105 can be used to enable the receiving UE to properly perform AGC to adjust the amplification strength when amplifying the power of the received signal. The signal used for AGC may be referred to as a synchronization signal, SL synchronization signal, sidelink reference signal, intermediate code, initial signal, wake-up signal, or other terms with equivalent technical meaning.

[0208] The PSCCH 1110, which includes control information, can be transmitted using symbols sent at the beginning of a time slot, and the PSSCH 1115, scheduled by the control information of PSCCH 1110, can then be transmitted. At least a portion of the SCI (Support Component Information) of the control information can be mapped to PSSCH 1115. Then, GUARD 1120 and AGC 1125 are present for PSFCH, and PSFCH 1130, as the physical channel for transmitting feedback information, is mapped.

[0209] exist Figure 11AIn the diagram, PSFCH 1130 is shown as the second symbol starting from the end of the timeslot. By ensuring GUARD 1120, which serves as a specific idle time period between PSSCH 1115 and PSFCH 1130, a UE that has already transmitted or received PSSCH 1115 can prepare to transmit or receive PSFCH 1130 (e.g., switch between transmission and reception). AGC 1125 may be present for PSFCH 1130. After PSFCH 1130, there is GUARD 1135, which serves as the idle duration for the specific time period.

[0210] The UE can be pre-configured with the location of the time slot that can transmit PSFCH. The pre-configuration of the location can refer to the following process: the location is predetermined when the UE is created, transmitted when connecting to the sidelink-related system, transmitted from the base station when connecting to the base station, or transmitted from another UE.

[0211] exist Figure 11A In the embodiments described, a preamble signal for performing AGC has been transmitted separately within the physical channel structure of the side link time slot. Alternatively, instead of transmitting a separate preamble signal, the receiver of the receiving UE may also perform AGC operations using the physical channel for control information or data transmission simultaneously with receiving the physical channel for control information or data transmission.

[0212] Figure 11B Examples of channel structures for time slots used for SL communication and SL-PRS in wireless communication systems according to various embodiments of this disclosure are shown. Figure 11B The physical channel mapped to the time slots used for SL communication is shown.

[0213] refer to Figure 11B The AGC 1105, which can be used to receive the UE, can be mapped to the first symbol of time slot 1100. Then, PSCCH 1110, PSSCH 1115, GUARD 1120, AGC 1125 for PSFCH, PSFCH 1130, and GUARD 1135 can be mapped sequentially. Additionally, SL-PRS 1140 can be mapped to time slot 1100.

[0214] SL-PRS 1140 can be mapped to at least one of the symbols available for PSSCH 1115, and the corresponding symbol can be time-division multiplexed (TDMed) and transmitted while separated from other physical channels via the time axis. Therefore, SL-PRS 1140 may affect the number of resource elements (REs) available for PSSCH 1115. Consequently, the amount of resources available for PSSCH 1115 may differ when transmitting SL signals including SL-PRS 1140, and resource allocation for SL data is required considering the symbols used to transmit SL-PRS.

[0215] SL-PRS 1140 can be distinguished by information that is distinguishable and pre-configured by the Phase 1 SCI, Phase 2 SCI, or other configurations, such as the resource set, time / frequency resources, comb N, symbol M, start symbol, frequency offset, etc. of the SL-PRS sent by the transmitting UE.

[0216] For a shared resource pool where the SL-PRS can be transmitted along with PSSCH 1115 used to transmit SL data and the second-SCI, the receiving UE can identify whether the transmission target of the SL-PRS 1140 is the receiving UE via the first-stage SCI and the second-stage SCI. Additionally, UEs other than those whose destination the SL-PRS 1140 is based on the first-stage SCI and / or the second-stage SCI can also receive the SL-PRS. In this case, the UE can determine whether to receive the SL-PRS 1140 via the tier 1 ID or tier 2 ID of the transmitting UE included in the first-stage SCI and the second-stage SCI, as well as information included in the first-stage SCI and the second-stage SCI (e.g., SL-PRS mode information and SL-PRS resource information).

[0217] Additionally, for a dedicated resource pool that only transmits SL-PRS 1140 and not PSSCH 1115, at least one of PSSCH 1115, GUARD 1120, AGC (PSFCH) 1125, PSSCH 1130, and GUARD 1135 may not be included in time slot 1100, and a UE may transmit SL-PRS 1140 to multiple UEs in one time slot 1100. For this purpose, at least one PSCCH 1110 including destination UE information may be included. When PSCCH 1110 includes one or more pieces of a Phase 1 SCI and has one or more associated SL-PRS 1140s, one piece of the Phase 1 SCI may indicate one SL-PRS 1140 (1:1 mapping), multiple pieces of the Phase 1 SCI may indicate one SL-PRS 1140 (N:1 mapping), or one piece of the Phase 1 SCI may indicate one or more SL-PRS 1140s (1:N mapping).

[0218] Figure 12 The process of a transmitting UE transmitting SL data in a wireless communication system according to an embodiment is illustrated.

[0219] Reference Figure 12 In step 1201, the transmitting UE (or the MAC entity of the transmitting UE) may receive an authorization for SL transmission (SL authorization), such as Figure 9 or Figure 10 As in the example. SL authorization is information indicating a set of resources, and the sending UE can determine the duration for which it can send PSCCH and the duration for which it can send PSSCH based on SL authorization.

[0220] In step 1202, the transmitting UE can select the destination for receiving SL data transmitted based on the SL grant associated with each SCI linked to the new transmission. The destination can be based on the active time of the SL DRX, or it can be the destination with the highest priority of at least one MAC CE or logical channel. The destination can be selected based on the criteria shown in Table 1 below.

[0221] Table 1

[0222]

[0223]

[0224] In step 1203, the transmitting UE can select a logical channel to send to the selected destination. If the SL data to be transmitted is in a logical channel, if the logical channel is available for SL-licensed CG, or if the logical channel is configured to use HARQ feedback, the transmitting UE can select an appropriate logical channel based on whether HARQ feedback is supported. These logical channels can be selected according to the criteria shown in Table 2 below.

[0225] Table 2

[0226]

[0227] In step 1204, the transmitting UE can select an MCS (or MCS table) to use in relation to the SL grants that exist (exist or occur) during the duration in which the PSSCH can be transmitted. The maximum and minimum values ​​in the MCS can be determined by a transport configuration (TxConfig), which can be determined by the highest priority of the logical channels included in the resources to be transmitted, the channel busy rate (CBR), etc. The transmitting UE can then send the selected MCS and the SL grants for the corresponding PSSCH duration to the associated SL HARQ entity. The transmitting UE can determine the number of symbols and REs available for the SL grants, as well as the size of the TB (TBS or TB size) that can be transmitted via the selected MCS.

[0228] In step 1205, the transmitting UE can allocate resources for transmitting SL data or MAC CE. The transmitting UE (or its MAC entity) can apply RRC parameters (e.g., sl-Priority, sl-PrioritisedBitRate (sPBR), and sl-BucketSizeDuration (sBSD)) to SL data transmission for each logical channel and maintain SBj for each logical channel j. SBj is incremented by a value obtained by multiplying sPBR by time and is initialized to 0 when the logical channel is established. Additionally, if SBj is greater than the product of sPBR and sBSD (SL bucket size), then SBj is configured to the SL bucket size. This process can be represented as shown in Table 3 below.

[0229] Table 3

[0230]

[0231] The transmitting UE can allocate resources to logical channels with SBj greater than 0 in the selected logical channels according to high priority (low sl-Priority indicates high priority) and configure MAC PDUs. This process can be represented as shown in Table 4 below.

[0232] Table 4

[0233]

[0234] In this case, the size available for resource allocation can be determined based on the TBS obtained in step 1204.

[0235] In step 1206, the sending UE can send SL data to the receiving UE. The specific UE operation is as follows.

[0236] The HARQ entity of the transmitting UE can request data transmission from the SL process of the transmitting UE. The HARQ entity of the transmitting UE can determine the SL transmission information. The SL transmission information may include at least one of the following: source layer 1 ID, destination layer 1 ID, SL process ID, HARQ process ID, projection type, HARQ feedback, and priority. The HARQ entity can transmit the SL transmission information and MAC PDU to the SL process. The SL process can identify whether the MAC PDU is transmittable based on whether the priority of the MAC PDU is greater than the priority of the UL or other transmissions. If the MAC PDU is transmittable, the SL process can instruct the PHY layer to transmit the SCI along with the SL transmission information according to the SL authorization, and can instruct the generation of a transmission according to the stored SL authorization in order to send the SL data to another UE.

[0237] Figure 13 The present disclosure illustrates a process for a UE to transmit SL data and SL-PRS in a wireless communication system according to various embodiments thereof.

[0238] In step 1301, the transmitting UE (or the MAC entity of the transmitting UE) may receive an SL grant for SL transmission, as in Figure 9 or Figure 10 As in the example. SL authorization is information indicating a set of resources, and the transmitting UE can determine the duration for which PSCCH can be transmitted and the duration for which PSSCH can be transmitted based on SL authorization. SL authorization can be an SL authorization that assumes SL-PRS multiplexed with PSSCH via an indication from the base station (e.g., DCI) or an indication from the PHY layer. With SL authorization assuming SL-PRS multiplexed with PSSCH, the transmitting UE can always include SL-PRS, or can predetermine a second TBS (2nd-TBS), which will be described later in operation 1406.

[0239] In step 1302, the transmitting UE can select the destination for receiving SL data based on the SL grant associated with each SCI linked to the new transmission. The destination can be within the active timeframe of the SL DRX, or it can be the destination with the highest priority among at least one MAC CE, logical channel, or SL-PRS. At least one SL-PRS destination can be selected. The destination can be selected to satisfy at least one of the following conditions.

[0240] - When there is a destination to which the SL-PRS should be sent, the sending UE can select the UE that needs to receive the SL-PRS as the destination, regardless of the logical channel or the priority of the SL-PRS.

[0241] - When there are multiple UEs as destinations for receiving SL-PRS, the sending UE can select the destination of the SL-PRS with the highest priority among the SL-PRS.

[0242] - Taking into account the packet delay budget of the logical channel, the delay requirement or delay budget of SL-PRS, or the remaining packet delay budget (PDB) of the logical channel and the remaining delay budget of SL-PRS, and the remaining time until the duration of PSSCH or SL-PRS transmission, the transmitting UE can choose a destination that includes the logical channel or SL-PRS so as not to exceed the range of the delay budget or the remaining delay budget, or can choose a destination with the lowest remaining delay budget.

[0243] - The bandwidth available for sending SL-PRS can vary depending on the SL license, and if the bandwidth of the SL license is insufficient for the SL-PRS transmission, the corresponding destination can be excluded.

[0244] - The transmitting UE can select the destination without considering SL-PRS, such as Figure 12 As shown, regardless of whether there is an SL-PRS to be sent to the destination of the SL-PRS, and in this case, the SL-PRS sent together with the SL data to the selected destination can be the SL-PRS to the selected destination and / or another UE.

[0245] If the transmitting UE is able to send SL-PRS to the selected destination or another UE during the corresponding PSSCH duration, the transmission (multiplexing) of PSSCH and SL-PRS can be determined. In this case, information about the physical channel used to configure SL-PRS (e.g., bandwidth, number of symbols, start symbol of SL-PRS, combination mode of SL-PRS, SL-PRS resource set, and at least one of SL-PRS frequency offset) can be stored and used in subsequent processes.

[0246] In step 1303, the transmitting UE can select a logical channel to which it will be sent to the selected destination. If the SL data to be sent is in a logical channel, if the logical channel is available for SL-licensed CG, or if the logical channel is configured to use HARQ feedback, the transmitting UE can select an appropriate logical channel based on whether HARQ feedback is supported.

[0247] In step 1304, the transmitting UE can select an MCS (or MCS table) to use in relation to SL grants that exist (exist or occur) during the duration on which PSSCH can be transmitted. The maximum and minimum values ​​in the MCS can be determined by a transport configuration (TxConfig), which can be determined by the highest priority of the SL-PRS or logical channel included in the resources to be transmitted, the channel busy rate (CBR), etc. The transmitting UE can send the selected MCS and the SL grants for the PSSCH resources to the associated sidelink HARQ entity. The transmitting UE can determine the number of symbols and REs available for SL grants and the TBS that can be transmitted via the selected MCS. If the transmission of SL-PRS is determined in step 1302, the transmitting UE can determine the TBS by considering the resources on which the SL-PRS is transmitted. That is, the transmitting UE can determine the TBS of the resources on which the SL-PRS is excluded.

[0248] In step 1305, the transmitting UE can allocate resources for transmitting SL data or MAC CE. The transmitting UE (or the MAC entity of the transmitting UE) can apply RRC parameters (e.g., sl-Priority, sl-PrioritisedBitRate (sPBR), and sl-BucketSizeDuration (sBSD)) to the SL data transmission of each logical channel and maintain SBj for each logical channel j. SBj is incremented by a value obtained by multiplying sPBR by time and is initialized to 0 when the logical channel is established. In addition, if SBj is greater than the product of sPBR and sBSD (SL bucket size), then SBj is configured to the SL bucket size. This process can be represented as shown in [Table 3].

[0249] The transmitting UE can allocate resources to logical channels with SBj greater than 0 in the selected logical channels according to high priority (low sl-Priority indicates high priority) and configure MAC PDUs. In this case, the amount of resources available for allocation can be determined based on the TBS obtained in step 1304.

[0250] In step 1306, the sending UE can send SL data to the receiving UE. The specific UE operation is as follows.

[0251] The HARQ entity of the transmitting UE can request data transmission from the sidelink process of the transmitting UE. The HARQ entity of the transmitting UE can determine the SL transmission information to be included in the SCI. The SL transmission information may include at least one of the following: source layer 1 ID, destination layer 1 ID, SL process ID, HARQ process ID, projection type, HARQ feedback, and priority. The HARQ entity can transmit the SL transmission information and the MAC PDU to the SL process. If the SL data transmission information differs from the SL-PRS transmission information (e.g., when priorities differ), the transmitting UE can determine the SL transmission information by using the higher of the SL data priority and the SL-PRS priority, or it can store the SL data priority and the SL-PRS priority separately and send them to the PHY layer. The SL process can identify whether the MAC PDU is transmissible based on whether the priority of the MAC PDU is greater than the priority of the UL or other transmissions. If the MAC PDU is transmissible, the SL process can instruct the PHY layer to transmit the SCI along with the SL transmission information according to the SL authorization, and can instruct the generation of a transmission according to the stored SL authorization to send the SL data to another UE.

[0252] If the transmission of SL-PRS and SL data will be indicated to the PHY layer together, information about the physical channel used to configure SL-PRS (e.g., bandwidth, comb N, symbol M, SL-PRS frequency offset, SL-PRS start symbol, and SL-PRS resource set ID) can also be sent for use when the PHY layer generates signals.

[0253] Information about the physical channels used to configure SL-PRS can be pre-configured by the base station via RRC, SIB, and pre-configuration, and each piece of information can be mapped to an ID. For example, a specific ID can indicate at least one of the following associated with that ID: bandwidth, comb N, symbol M, SL-PRS frequency offset, and SL-PRS start symbol. Alternatively, the transmitting UE can pre-send request information associated with a specific destination and service to the base station via RRC messages, and the base station can provide the available SL-PRS resource set and mapping IDs based on this request information.

[0254] Figure 14 The present disclosure illustrates a process for a UE to transmit SL data and SL-PRS in a wireless communication system according to various embodiments thereof.

[0255] In step 1401, the transmitting UE (or the MAC entity of the transmitting UE) may receive an SL grant for SL transmission, as shown in Figure 9 or Figure 10As in the example. SL authorization is information indicating a set of resources, and the transmitting UE can determine the duration for which PSCCH can be transmitted and the duration for which PSSCH can be transmitted based on SL authorization. SL authorization can be an SL authorization that assumes SL-PRS is multiplexed with PSSCH through an indication from the base station (e.g., DCI) or an indication from the PHY layer. Based on an SL authorization that assumes SL-PRS is multiplexed, the transmitting UE can include SL-PRS, or can first determine a second TBS (2nd-TBS), which will be described later in step 1406.

[0256] In step 1402, the transmitting UE can select the destination for receiving SL data transmitted based on the SL grant associated with each SCI connected to the new transmission. The destination can be within the active timeframe of the SL DRX, or it can be the destination with the highest priority among at least one MAC CE, logical channel, or SL-PRS. At least one SL-PRS transmission target can be selected. The destination can be selected to satisfy at least one of the following conditions.

[0257] - When there is a destination to which the SL-PRS should be sent, the sending UE can select the UE that needs to receive the SL-PRS as the destination, regardless of the logical channel or the priority of the SL-PRS.

[0258] - When there are multiple UEs as destinations for receiving SL-PRS, the sending UE can select the destination of the SL-PRS with the highest priority among the SL-PRS.

[0259] - Taking into account the packet delay budget of the logical channel, the delay requirement or delay budget of SL-PRS, or the remaining packet delay budget (PDB) of the logical channel and the remaining delay budget of SL-PRS, and the remaining time until the duration of PSSCH or SL-PRS transmission, the transmitting UE can choose a destination that includes the logical channel or SL-PRS so as not to exceed the range of the delay budget or the remaining delay budget, or can choose a destination with the lowest remaining delay budget.

[0260] - The bandwidth available for sending SL-PRS can vary depending on the SL license, and if the bandwidth of the SL license is insufficient for the SL-PRS transmission, the corresponding destination can be excluded.

[0261] - The transmitting UE can select the destination without considering SL-PRS, such as Figure 12 As shown, regardless of whether there is an SL-PRS to be sent to the destination of the SL-PRS, and in this case, the SL-PRS sent together with the SL data to the selected destination can be the SL-PRS to the selected destination and / or another UE.

[0262] In step 1403, the transmitting UE can select a logical channel to send to the selected destination. If the SL data to be transmitted is in a logical channel, if the logical channel is available for SL-licensed CG, or if the logical channel is configured to use HARQ feedback, the transmitting UE can select an appropriate logical channel based on whether HARQ feedback is supported.

[0263] In step 1404, the transmitting UE can select the MCS (or MCS table) to be used in relation to the SL grants that exist (exist or occur) during the duration in which PSSCH can be transmitted. The maximum and minimum values ​​in the MCS can be determined by the transport configuration (TxConfig), which can be determined by the highest priority of the SL-PRS or logical channel included in the resources to be transmitted, the channel busy rate (CBR), etc. The transmitting UE can send the selected MCS and the SL grants for the PSSCH resources to the associated sidelink HARQ entity. The transmitting UE can determine the TBS based on the number of symbols and REs available for SL grants and the selected MCS.

[0264] In step 1405, the transmitting UE can allocate resources for transmitting SL data or MAC CE. The transmitting UE (or the MAC entity of the transmitting UE) can apply RRC parameters (e.g., sl-Priority, sl-PrioritisedBitRate (sPBR), and sl-BucketSizeDuration (sBSD)) to the SL data transmission of each logical channel and maintain SBj for each logical channel j. SBj is incremented by a value obtained by multiplying sPBR by time and is initialized to 0 when the logical channel is established. If SBj is greater than the product of sPBR and sBSD (SL bucket size), then SBj is configured to the SL bucket size. This process can be represented as shown in [Table 3].

[0265] The transmitting UE can allocate resources to logical channels with SBj greater than 0 in the selected logical channels according to high priority (low sl-priority indicates high priority) and configure MAC PDUs. In this case, the amount of resources available for allocation can be determined based on the TBS obtained in step 1404. When there is an SL-PRS to be sent to the selected destination or another UE during the PSSCH duration, and there is a logical channel with a higher priority than the SL-PRS, the UE can allocate as many resources as SBj associated with the logical channel with a higher priority than the SL-PRS, or allocate as many resources as SBj associated with the logical channel with a priority equal to or higher than the SL-PRS.

[0266] If the SL-PRS has the same priority as the logical channel, the transmitting UE can prioritize adding the SL-PRS, prioritizing adding data to the logical channel, or prioritizing adding the logical channel or SL-PRS that should have been transmitted earlier, by comparing the remaining packet delay budget (PDB) of each logical channel with the remaining delay budget of the SL-PRS. Alternatively, depending on the UE implementation, it can be determined which logical channel among those with the same priority as the SL-PRS will be included.

[0267] After the transmitting UE allocates data to a logical channel with the same or higher priority as the SL-PRS in step 1405, the transmitting UE may determine the TBS including the SL-PRS in step 1406, provided there are remaining allocable resources. For the TBS, symbols used for SL-PRS transmission may be excluded. The determined TBS including the SL-PRS may be referred to as the second TBS (2nd-TBS) to distinguish it from the TBS determined in step 1404.

[0268] In step 1407, if the size of the second TBS (2nd-TBS) determined in step 1406 is not available for allocating the logical channel data included in step 1405, the transmitting UE may determine not to transmit the SL-PRS along with the SL data. When it is determined not to transmit the SL-PRS along with the SL data, the transmitting UE may proceed to step 1408.

[0269] Furthermore, in step 1407, even if the size of the second TBS (2nd-TBS) is insufficient to allocate the logical channel data included in step 1405, the transmitting UE may consider the remaining delay budget of the SL-PRS or the delay budget of the logical channel to determine whether to transmit the SL-PRS together with the SL data. Alternatively, even if the size of the second TBS (2nd-TBS) is insufficient to allocate the logical channel data included in step 1405, the transmitting UE may determine whether to transmit the SL-PRS together with the SL data according to the UE implementation. If the second TBS (2nd-TBS) has a size available for allocating the data of the logical channel included in step 1405, the transmitting UE may determine to transmit the SL-PRS together with the SL data. When it is determined that the SL-PRS will be transmitted together with the SL data, the transmitting UE may perform operation 1409.

[0270] In step 1408, the transmitting UE can allocate data from the logical channel to the remaining resources of the TBS, as shown in Table 4 above. In this case, the SL-PRS may not be multiplexed.

[0271] In step 1409, the transmitting UE can allocate the remaining resources of the logical channel to the second TBS (2nd-TBS), as shown in Table 4. The second TBS (2nd-TBS) can be determined in step 1406, where SL-PRS and PSSCH are multiplexed for transmission together. The determination and comparison of the second TBS (2nd-TBS) can be performed in step 1404 or another operation.

[0272] In step 1410, the sending UE can send SL data to the receiving UE. The specific UE operation is as follows.

[0273] The HARQ entity of the transmitting UE can request data transmission from the SL process of the transmitting UE. The HARQ entity of the transmitting UE can determine SL transmission information. SL transmission information may include at least one of source layer 1 ID, destination layer 1 ID, SL process ID, HARQ process ID, projection type, HARQ feedback, and priority. The HARQ entity can transmit the SL transmission information and MAC PDU to the SL process. If the SL data transmission information differs from the SL-PRS transmission information (e.g., when priorities differ), the transmitting UE can determine the SL transmission information by using the higher of the SL data priority and the SL-PRS priority, or it can store the SL data priority and the SL-PRS priority separately and send them to the PHY layer. The SL process can identify whether a MAC PDU is transmissible based on whether the priority of the MAC PDU is greater than the priority of the UL or other transmissions. If the MAC PDU is transmissible, the SL process can instruct the PHY layer to transmit the SCI along with the SL transmission information according to the SL authorization, and can instruct the generation of a transmission according to the stored SL authorization to send the SL data to another UE.

[0274] If the transmission of SL-PRS and SL data should be indicated to the PHY layer together, information about the physical channel for configuring SL-PRS (e.g., bandwidth, comb N, symbol M, SL-PRS frequency offset, SL-PRS start symbol, and SL-PRS resource set ID) can also be sent for use by the PHY layer when generating signals.

[0275] Information about the physical channels used to configure SL-PRS can be pre-configured by the base station via RRC, SIB, and pre-configuration, and each piece of information can be mapped to an ID. For example, a specific ID can indicate at least one of the following associated with that ID: bandwidth, comb N, symbol M, SL-PRS frequency offset, and SL-PRS start symbol. Alternatively, the transmitting UE can pre-send request information associated with a specific destination and service to the base station via RRC messages, and the base station can provide the available SL-PRS resource set and mapping IDs based on this request information.

[0276] Figure 15 The process of a transmitting UE transmitting SL-PRS in a wireless communication system according to an embodiment is illustrated.

[0277] In step 1501, the transmitting UE (or the MAC entity of the transmitting UE) may receive an authorization for SL transmission (SL authorization), such as Figure 9 or Figure 10 As in the example. SL authorization is information indicating a set of resources, and the transmitting UE can determine the duration for which PSCCH can be transmitted and the duration for which PSSCH can be transmitted based on SL authorization. SL authorization can be an SL authorization that uses an SL-PRS specifying a resource pool in which PSSCH is not transmitted.

[0278] In step 1502, the transmitting UE can select at least one destination to receive SL data transmitted based on the SL grant associated with each SCI linked to the new SL-PRS transmission. The destination can be within the active timeframe based on the SL DRX, or it can be the destination with the highest priority in at least one SL-PRS transmission. At least one SL-PRS transmission target can be selected. The destination can be selected to satisfy at least one of the following conditions.

[0279] When multiple UEs are available as destinations for receiving SL-PRS, the transmitting UE can select the destination of the SL-PRS with the highest priority. Alternatively, if the number of destinations for receiving SL-PRS is the same as the number of target UEs that can transmit via SL authorization, all destinations can be selected in order of high priority or without regard to priority.

[0280] - Taking into account the delay requirement or delay budget of SL-PRS or the remaining delay budget of SL-PRS and the remaining time until the duration of SL-PRS transmission, the transmitting UE may select at least one destination that includes SL-PRS so as not to exceed the range of the delay budget or the remaining delay budget.

[0281] - The bandwidth available for sending SL-PRS can vary depending on the SL license, and if the bandwidth of the SL license is insufficient for the SL-PRS transmission, the corresponding destination can be excluded.

[0282] - The transmitting UE can determine to send SL-PRS to another UE and the selected destination. In this case, information about the physical channels used to configure SL-PRS (e.g., bandwidth, number of symbols, SL-PRS combination mode, SL-PRS resource set, SL-PRS frequency offset, and SL-PRS start symbol) can be stored and then used in subsequent processes.

[0283] In step 1503, the transmitting UE can determine the resources used for transmitting SL-PRS. That is, it can determine the number of symbols available for SL-PRS in the time slot associated with the PSCCH or in the same time slot as the PSCCH.

[0284] The transmitting UE can prioritize allocating higher-priority SL-PRSs to symbols available for SL-PRS transmission. If fewer than all SL-PRSs are transmittable (or transmission resources are insufficient), the transmitting UE can allocate resources such that as many SL-PRSs as possible can be transmitted within those resources, regardless of their priority.

[0285] Alternatively, the transmitting UE may allocate SL-PRS to resources in the order of their highest priority or in the order of their lowest remaining delay budget, regardless of priority.

[0286] The transmitting UE can allocate SL-PRS to resources in order of high priority, and SL-PRS with the same priority can be allocated according to the UE implementation method or in order of low remaining delay budget.

[0287] If the transmitting UE is no longer able to allocate any SL-PRS to the resource in order of high priority (e.g., if there is 1 symbol remaining, but subsequent priority SL-PRS require 2 symbols), then the SL-PRS with the highest priority among those using 1 symbol can be allocated to the resource.

[0288] In step 1504, the transmitting UE can perform an SL-PRS transmission. Specifically, the upper layer (e.g., MAC entity) of the transmitting UE can request an SL-PRS transmission from the lower layer (e.g., PHY layer) and perform the SL-PRS transmission via the PHY layer. In this case, the transmitting UE can generate an SL-PRS and add SL transmission information to the first-stage SCI to send the SL-PRS to the receiving UE. The SL transmission information may include at least one of the following: source layer 1 ID, source layer 2 ID, destination layer 1 ID, destination layer 2 ID, SL process ID, HARQ process ID, projection type, HARQ feedback, priority, SL-PRS bandwidth, number of SL-PRS symbols, SL-PRS start symbol, SL-PRS comb N, and SL-PRS frequency offset.

[0289] If the SL data transmission information includes multiple SL-PRS transmissions (e.g., when priorities are different), the transmitting UE can determine the SL transmission information by using the higher priority among the SL-PRS to be transmitted, or it can store the priorities of multiple SL-PRS separately and send them to the PHY layer. The transmitting UE can determine whether to transmit the SL-PRS based on whether the priority of the SL-PRS is greater than the priority of the UL or other SL transmissions. If the SL-PRS is transmittable, the transmitting UE can instruct the PHY layer to transmit the SCI along with the SL transmission information according to the SL grant, and can instruct the generation of the SL-PRS transmission according to the stored SL grant, so as to send the SL-PRS to another UE.

[0290] The transmitting UE can send information about the physical channels used to configure SL-PRS (bandwidth, comb N, symbol size M, SL-PRS priority, SL-PRS frequency offset, SL-PRS start symbol, and SL-PRS resource set ID), allowing the PHY layer to use this information when generating signals. The information about the physical channels used to configure SL-PRS can be pre-configured by the base station via RRC, SIB, and pre-configuration, and each piece of information can be mapped to an ID. For example, a specific ID can indicate at least one of the bandwidth, comb N, symbol M, SL-PRS frequency offset, and SL-PRS start symbol associated with that ID. Alternatively, the transmitting UE can pre-send request information associated with a specific destination and service to the base station via RRC messages, and the base station can provide available SL-PRS resource sets and mapping IDs based on this request information.

[0291] The methods described in this paper can be implemented through hardware, software, or a combination of hardware and software.

[0292] When the method is implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors within an electronic device. At least one program includes instructions to cause the electronic device to perform the method according to various embodiments of the present disclosure as defined by the appended claims and / or disclosed herein.

[0293] These programs (software modules or software) can be stored in non-volatile memory, including random access memory and flash memory, ROM, electrically erasable programmable read-only memory (EEPROM), disk storage devices, CD-ROMs, DVDs, or other types of optical storage devices or magnetic tape cassettes. Alternatively, any combination of some or all of them can form a memory storing programs. Furthermore, multiple such memories can be included in an electronic device.

[0294] The program can be stored in an attachable storage device that can access the electronic device via a communication network such as the Internet, intranet, local area network (LAN), wide LAN (WLAN), and storage area network (SAN), or a combination thereof. Such a storage device can access the electronic device via an external port. A separate storage device on a communication network can access portable electronic devices.

[0295] Here, each block of the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium that can instruct the computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium produce an article of writing including instruction means for implementing the functions specified in one or more flowchart blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus, thereby producing a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowchart blocks.

[0296] Furthermore, each block in the flowchart diagram may represent a module, segment, or section of code, which includes one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in a block may occur out of order. For example, depending on the functions involved, two blocks shown consecutively may actually execute substantially simultaneously, or these blocks may sometimes execute in reverse order.

[0297] As used in embodiments of this disclosure, a unit refers to a software element or hardware element that performs a predetermined function, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC). However, the unit is not always limited to software or hardware. The unit may be configured to reside in addressable storage media or run one or more processors. Therefore, the unit includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions provided by the unit may be combined into a smaller number of elements or units, or divided into a larger number of elements or units. Furthermore, elements and units may be implemented as one or more central processing units within a playback device or secure multimedia card. The unit in the embodiments may include one or more processors.

[0298] Although this disclosure has been described with reference to various embodiments, various changes may be made without departing from the spirit and scope of this disclosure, which is not limited by the detailed description and embodiments, but by the appended claims and their equivalents.

Claims

1. A method for side-link (SL) communication performed by a terminal, the method comprising: Receive SL authorization from the base station for SL transmission; In the presence of an SL Positioning Reference Signal (SL-PRS) for transmission to the selected destination, a first transport block size (TBS) including the SL-PRS is identified based on the SL authorization; and If all data in a logical channel with a higher priority than the logical channel of the SL-PRS is allocated resources of the SL authorization, the SL-PRS is transmitted based on the SL authorization.

2. The method according to claim 1, further comprising: If all data within a logical channel with a higher priority than the SL-PRS is not allocated resources under the SL grant, it is identified that the SL-PRS is not transmitted based on the SL grant. Identify a second TBS that does not have SL-PRS.

3. The method according to claim 2, in, The second TBS is identified based on the resource elements allocated according to the SL authorization, as well as the modulation and coding scheme.

4. The method according to claim 1, in, The first TBS is determined based on resources other than the symbols used for the SL-PRS.

5. The method according to claim 1, further comprising: Select the destination; as well as Select a logical channel for transmission to the destination.

6. The method according to claim 5, in, The selected logical channel includes logical channels with SL data or logical channels enabled for mixed automatic repeat request feedback.

7. A terminal for side-link (SL) communication, the terminal comprising: transceiver; as well as A controller, coupled to the transceiver and configured to: Receive SL authorization from the base station for SL transmission. In the presence of an SL Positioning Reference Signal (SL-PRS) for transmission to the selected destination, a first transport block size (TBS) including the SL-PRS is identified based on the SL authorization. If all data in a logical channel with a higher priority than the logical channel of the SL-PRS is allocated resources of the SL authorization, the SL-PRS is transmitted based on the SL authorization.

8. The terminal according to claim 7, wherein, The controller is also configured to: If all data in a logical channel with a higher priority than the SL-PRS is not allocated resources under the SL grant, it is identified that the SL-PRS is not transmitted based on the SL grant. Identify a second TBS that does not have SL-PRS.

9. The terminal according to claim 8, in, The second TBS is identified based on the resource elements allocated according to the SL authorization, as well as the modulation and coding scheme.

10. The terminal according to claim 7, in, The first TBS is determined based on resources other than the symbols used for the SL-PRS.

11. The terminal according to claim 7, wherein, The controller is also configured to: Select the destination, and Select a logical channel for transmission to the destination.

12. The terminal according to claim 11, in, The selected logical channel includes logical channels with SL data or logical channels enabled for mixed automatic repeat request feedback.

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