Ue and resource selection method for back-to-back transmission in sidelink communications

Abstract

A resource selection method for back-to-back transmissions in sidelink (SL) communications by a user equipment (UE), the method comprising: a higher layer of the UE triggering a first layer of the UE to perform a resource selection procedure based on one or more parameters provided by the higher layer to report a remaining set of candidate resources, the one or more parameters being provided by the higher layer; the remaining set of candidate resources includes at least one set of resources in consecutive time slots.

Description

Background Art 1. Technical Field

[0001] The present disclosure relates to the field of communication systems, and more specifically, to a user equipment (UE) and a resource selection method for back-to-back transmission in sidelink (SL) communications, which can provide good communication performance and / or high reliability. 2. Background technology

[0002] In the development of radio wireless transmission and reception directly between two devices (which is generally referred to as device-to-device (D2D) communication), it was first developed by the 3rd generation partnership project (3GPP) and introduced in Release 12 (officially designated as sidelink communication), which is used for public safety emergency purposes (such as mission-critical communications) to mainly support low data rates and voice-type connections. In 3GPP Releases 14, 15 and 16, sidelink technology was developed to additionally support vehicle-to-everything (V2X) communications, thereby improving road safety and advanced / autonomous driving use cases, where V2X communications are part of the global development of intelligent transportation systems (ITS). In order to further expand support for sidelink technology to a wider range of applications and devices that utilize limited power / batteries, in Release 17, the technology has been further enhanced in the areas of power conservation and transceiver link reliability. For Release 18, 3GPP is seeking to evolve wireless technology and extend its operation into unlicensed spectrum for greater bandwidth, faster data rates, and easier market adoption of D2D communications using sidelinks without requiring mobile cellular operators to configure and allocate a portion of their extended mobile radio spectrum for data services that do not pass through their mobile networks.

[0003] Therefore, there is a need for a UE and resource selection method for back-to-back transmission in SL communication, which can solve the problems in the prior art, avoid transmission conflicts, ensure access to unlicensed wireless channels for its own transmission, provide good communication performance, and / or provide high reliability. Summary of the invention

[0004] In a first aspect of the present disclosure, a UE includes a first layer and a higher layer coupled to the first layer. The higher layer is configured to trigger the first layer to perform a resource selection process based on one or more parameters to report a remaining set of candidate resources, the one or more parameters being provided by the higher layer, the remaining set of candidate resources including at least one set of resources in consecutive time slots.

[0005] In a second aspect of the present disclosure, a resource selection method for back-to-back transmission in SL communication performed by a UE includes: a higher layer of the UE triggers a first layer of the UE to perform a resource selection process based on one or more parameters to report a remaining set of candidate resources, the one or more parameters being provided by the higher layer, and the remaining set of candidate resources including at least one set of resources in consecutive time slots.

[0006] In a third aspect of the present disclosure, a UE includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The UE is configured to execute the above method.

[0007] In a fourth aspect of the present disclosure, a non-transitory machine-readable storage medium has instructions stored thereon that, when executed by a computer, cause the computer to perform the above method.

[0008] In a fifth aspect of the present disclosure, a chip includes a processor configured to call and run a computer program stored in a memory so that a device equipped with the chip executes the above method.

[0009] In a sixth aspect of the present disclosure, a computer-readable storage medium storing a computer program causes a computer to execute the above method.

[0010] In a seventh aspect of the present disclosure, a computer program product comprises a computer program, which enables a computer to execute the above method.

[0011] In an eighth aspect of the present disclosure, a computer program causes a computer to execute the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present disclosure or related technologies, the following figures to be described in the embodiments are briefly introduced. Obviously, the drawings are only some embodiments of the present disclosure, and ordinary technicians in this field can obtain other drawings based on these drawings without prerequisites.

[0013] Figure 1 is a block diagram of a UE communicating in a communication network system provided by an embodiment of the present disclosure;

[0014] Figure 2 is a schematic diagram of a user plane protocol stack provided by an embodiment of the present disclosure;

[0015] Figure 3 is a schematic diagram of a control plane protocol stack provided by an embodiment of the present disclosure;

[0016] Figure 4 is a flow chart of a resource selection method provided by an embodiment of the present disclosure, the method being used for back-to-back transmission in SL communication performed by a UE;

[0017] Figure 5 is a schematic diagram of an exemplary resource selection method provided by an embodiment of the present disclosure, the method being used for multi-consecutive slots transmission (MCSt) in SL communication;

[0018] Figure 6 is a schematic diagram of an exemplary resource selection method provided by an embodiment of the present disclosure, the method being used to perform MCSt when sidelink hybrid automatic repeat request (SL-HARQ) feedback is enabled;

[0019] Figure 7 is a flow chart of a resource selection method provided by an embodiment of the present disclosure, the method being used for back-to-back transmission in a SL performed by a UE;

[0020] Figure 8 is a block diagram of a UE for wireless communication provided by an embodiment of the present disclosure;

[0021] Fig. 9 It is a block diagram of a system for wireless communication provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] The following describes the embodiments of the present disclosure in detail with reference to the accompanying drawings, using technical issues, structural features, achieved purposes and effects. Specifically, the terms in the embodiments of the present disclosure are only used for the purpose of describing specific embodiments, rather than limiting the present disclosure.

[0023] Unlicensed spectrum:

[0024] Traditionally, Wi-Fi and Bluetooth wireless technologies typically use unlicensed (also known as unlicensed) radio spectrum in the 2.4 GHz and 5 GHz bands for short-range communications (such as from only a few meters to tens of meters). It is often required to carry more traffic on unlicensed bands than any other radio band because the spectrum is free / uncompensated for use by anyone as long as the communication equipment complies with specific local technical regulations. In addition, Wi-Fi, Bluetooth and other radio access technologies (RATs) (such as licensed-assisted access (LAA) based on 4G long term evolution (LTE) and new radio unlicensed (NR-U) based on 5G new radio (NR) mobile systems from 3GPP) also operate in the same unlicensed bands. In order for devices of different RATs (Wi-Fi, Bluetooth, LAA, NR-U, and possibly other RATs) to operate simultaneously in the same geographic area and coexist fairly without causing significant interference and disruption to each other's transmissions, clear channel access (CCA) protocols such as listen-before-talk (LBT) used in LAA and NR-U and carrier sense multiple access / collision avoidance (CSMA / CA) used in Wi-Fi and Bluetooth are employed before any wireless transmission is performed to ensure that one radio device does not transmit when another radio device is already transmitting on the same channel.

[0025] In order for the sidelink radio technology to also operate and coexist with existing RATs already operating in unlicensed bands, an LBT-based scheme may be employed to ensure that there is no ongoing activity on the radio channel before attempting to access the channel for transmission. For example, when a sidelink UE successfully performs a type 1 LBT, the UE has the right to access and occupy the unlicensed channel for the duration of the channel occupancy time (COT). However, during the acquired COT, if the COT initiating sidelink UE or the COT responding sidelink UE does not perform a wireless transmission during an idle period longer than 25us, a device of another RAT may still obtain access to the channel. Therefore, access to the channel may be lost until another successful LBT is performed. A potential solution to the problem of losing access to the channel may be back-to-back (B2B) transmission.

[0026] Back-to-back transmission

[0027] The main purpose of B2B transmission (which may also be referred to as "burst transmission" or "multiple consecutive time slot transmission (MCSt)") is to enable SL communication UE to continuously occupy the unlicensed channel for a longer time (i.e., more than one time slot) without the risk of losing access to the channel to wireless transmission (Tx) devices of other radio access technologies (RATs). This may be particularly important and useful for SL Tx-UEs operating in unlicensed radio frequency spectrum, which have large-sized data transmission blocks (TB) or medium access control (MAC) packet data units (PDU), require multiple retransmissions, disable sidelink hybrid automatic repeat request (SL-HARQ) feedback, and / or have short delay requirements (packet delay budget, PDB). When the unlicensed wireless channel is busy / congested (for example, where many devices try to access the channel for transmission at the same time), gaining access to the channel may be difficult and take a long time due to the random backoff timers and priority level classification in the LBT process. Therefore, when the UE finally has the opportunity / chance to gain access to the wireless channel for a COT length that may last for several milliseconds (e.g., 4, 8, or 10 ms), it is desirable to maintain the channel access as long as possible (e.g., all or most of the COT length) to send as much data as possible by continuously transmitting in the unlicensed channel so that wireless devices of other RATs will not have the opportunity to access the channel.

[0028] Multiple start symbols (in the time slot used for SL transmission)

[0029] As mentioned above, before the UE is allowed to transmit any SL signal or channel on an unlicensed channel, the UE needs to first perform a Type 1 LBT channel access procedure on the channel to obtain a COT. Depending on the random selection result of the backoff counter used for channel sensing, the required duration for performing Type 1 LBT is unpredictable. Therefore, the UE usually needs to perform a Type 1 LBT procedure with a time margin to account for the randomness of the counter before the scheduled transmission. According to the existing SL frame structure, the UE performs SL data and associated control channel transmissions at the time slot boundary, and each data plus control transmission length is one time slot. This means that the end / completion time of Type 1 LBT can ideally be completed just before the boundary of the scheduled time slot for transmission. However, due to unpredictable random selection results, this may not always happen, and the countdown process is also suspended when other devices are accessing the channel. In order to offset this effect and allow the UE to have more opportunities to access the channel, the UE can be allowed to start SL transmission from different positions / locations / symbols within the time slot (for example, in the middle of the time slot, symbol 7 in a time slot with 14 symbols).

[0030] Mode 2 resource selection in sidelink

[0031] In the existing design of resource allocation mechanism for SL communication, the mode 2 resource selection method relies on the SL transmission UE to perform autonomous selection of resources from the SL resource pool for its own data message transmission. In this exemplary method, the selection of transmission resources is not random but based on the listening and reservation strategy to avoid conflicts with other SL transmission UEs operating in the same resource pool. In this exemplary resource selection strategy, the transmission UE listens to the channel (which is different from LBT channel listening) within the listening window to detect and decode SL resource reservation information from other transmission UEs. Based on the resource reservation information, the UE excludes some reserved resources from the selection to avoid transmission conflicts. Similarly, when the UE sends data and control messages, the UE also sends / broadcasts its own resource reservation information in the resource pool so that other UEs can avoid selecting the same resources. In the existing resource selection and reservation signaling design, the time gap between two consecutive resources can be separated by up to 31 time slots. Using this type of resource selection method is not ideal for MCSt because there is no guarantee that resources can be selected continuously in time.

[0032] In the exemplary resource selection method for sidelink communication proposed in the present application, the main purpose is to ensure that there is at least one set of available / candidate resources that are continuous in time for MCSt and do not conflict with other reservations and transmissions. Thereby, it is ensured that access to the unlicensed wireless channel is reserved for its own transmission. Other benefits from adopting the proposed exemplary resource selection method for MCSt may include one or more of the following: 1. Allowing sharing of COT information and coordination with other UEs to fully utilize COT; 2. It can be easily adapted to send packet data units (MAC PDUs) or data transmission blocks (TBs) that require SL-HARQ feedback.

[0033] In some embodiments, Figure 1 One or more UEs 10 (such as a first UE) and one or more UEs 20 (such as a second UE) communicating in a communication network system 30 provided by an embodiment of the present disclosure are shown. The communication network system 30 includes one or more UEs 10 and one or more UEs 20. The UE 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and the transceiver 13. The UE 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and the transceiver 23. The processor 11 or the processor 21 may be configured to implement the functions, processes and / or methods proposed in this specification. The radio interface protocol layer may be implemented in the processor 11 or the processor 21. The memory 12 or the memory 22 is operatively coupled to the processor 11 or the processor 21, and stores various information to operate the processor 11 or the processor 21. The transceiver 13 or the transceiver 23 is operatively coupled to the processor 11 or the processor 21, and sends and / or receives radio signals.

[0034] The processor 11 or the processor 21 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory 12 or the memory 22 may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium and / or other storage devices. The transceiver 13 or the transceiver 23 may include a baseband circuit to process radio frequency signals. When the embodiment is implemented in software, the techniques described herein may be implemented using modules (e.g., processes, functions, etc.) that perform the functions described herein. These modules may be stored in the memory 12 or the memory 22 and executed by the processor 11 or the processor 21. The memory 12 or the memory 22 may be implemented within the processor 11 or the processor 21 or outside the processor 11 or the processor 21, in which case these modules may be communicatively coupled to the processor 11 or the processor 21 via various means known in the art.

[0035] Communications between UEs involve vehicle-to-vehicle (V2X) communications, including vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), and vehicle-to-infrastructure / network (V2I / N) based on sidelink technologies developed under 3rd Generation Partnership Project (3GPP) LTE and NR Releases 17, 18 and above. UEs communicate directly with each other via a sidelink interface such as a PC5 interface. Some embodiments of the present disclosure relate to sidelink communication technologies in 3GPP NR Releases 17 and above, such as providing cellular–vehicle to everything (C-V2X) communications.

[0036] In some embodiments, UE 10 may be a sidelink packet TB transmitting UE (Tx-UE). UE 20 may be a sidelink packet TB receiving UE (Rx-UE) or a peer UE. Sidelink packet TB Rx-UE may be configured to send ACK / NACK feedback to packet TB Tx-UE. Peer UE 20 is another UE communicating with Tx-UE 10 in the same SL unicast or multicast session.

[0037] Figure 2 An example user plane protocol stack of an embodiment of the present disclosure is shown. Figure 2It is shown that in some embodiments, in the user plane protocol stack, the service data adaptation protocol (SDAP), the packet data convergence protocol (PDCP), the radio link control (RLC), and the media access control (MAC) sublayer and the physical (PHY) layer (also known as the first layer or layer 1 (L1) layer) can be terminated in the UE 10 and the base station 40 (such as gNB) on the network side. In one example, the PHY layer provides transport services to higher layers (e.g., MAC, radio resource control (RRC), etc.). In one example, the services and functions of the MAC sublayer may include mapping between logical channels and transport channels, multiplexing / demultiplexing of MAC service data units (SDUs) belonging to one or different logical channels to / from TBs delivered to / from the PHY layer, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA)), priority handling between UEs through dynamic scheduling, priority handling between logical channels of a UE through logical channel prioritization, and / or padding. The MAC entity may support one or more parameter sets and / or transmission timing. In one example, mapping restrictions in logical channel prioritization may control which parameter set and / or transmission timing a logical channel may use. In one example, the RLC sublayer may support transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM) transmission modes. RLC configuration can be per logical channel, independent of parameter set and / or transmission time interval (TTI) duration. In one example, automatic repeat request (ARQ) can operate on any parameter set and / or TTI duration that the logical channel is configured with.In one example, the services and functions of the PDCP layer for the user plane may include sequence numbering, header compression and decompression, delivery of user data, reordering and duplicate detection, PDCP PDU routing (e.g., in the case of split bearers), retransmission of PDCP SDUs, encryption, decryption and integrity protection, PDCP SDU discard, PDCP reconstruction and data recovery for RLC AM, and / or repetition of PDCP PDUs. In one example, the services and functions of SDAP may include mapping between QoS flows and data radio bearers. In one example, the services and functions of SDAP may include mapping quality of service indicators (QFI) in downlink (DL) and uplink (UL) packets. In one example, the protocol entities of SDAP may be configured for separate PDU sessions.

[0038] Figure 3 An example control plane protocol stack of an embodiment of the present disclosure is shown. Figure 2It is shown that in some embodiments, in the control plane protocol stack, the PDCP, RLC and MAC sublayers and the PHY layer can be terminated in the UE 10 and the base station 40 (such as a gNB) on the network side and perform the above-mentioned services and functions. In one example, RRC is used to control radio resources between the UE and the base station (such as a gNB). In one example, the RRC can be terminated in the UE and the gNB on the network side. In one example, the services and functions of the RRC may include broadcasting of system information related to the access stratum (AS) and the non-access stratum (NAS), paging initiated by the 5GC or the RAN, establishment, maintenance and release of the RRC connection between the UE and the RAN, security functions including key management, establishment, configuration, maintenance and release of signaling radio bearers (SRB) and data radio bearers (DRB), mobility functions, QoS management functions, UE measurement reports and control of reports, detection of radio link failures and recovery therefrom, and / or non-access stratum (NAS) message delivery from / to the UE to / from the NAS. In one example, the NAS control protocol may be terminated in the UE and AMF (access and mobility management function) on the network side, and may perform functions such as authentication, mobility management between the UE and AMF for 3GPP access and non-3GPP access, and session management between the UE and SMF (session management function) for 3GPP access and non-3GPP access.

[0039] When a specific application is executed and the specific application in the UE requires a data communication service, the application layer responsible for executing the specific application provides the NAS layer with application related information, i.e., application group / category / priority information / ID. In this case, the application related information may be preconfigured / defined in the UE. (Alternatively, the application related information is received from the network to be provided from the AS (RRC) layer to the application layer, and when the application layer starts the data communication service, the application layer requests the AS (RRC) layer to provide the information to receive the information.)

[0040] In some embodiments, a higher layer of UE 10 is configured to trigger a first layer of UE 10 to perform a resource selection process based on one or more parameters to report a remaining set of candidate resources, the one or more parameters provided by the higher layer, the remaining set of candidate resources including at least one set of resources in consecutive time slots. In some examples, the first layer refers to layer 1 (L1) / PHY layer. In some examples, the higher layer refers to the MAC layer. This can solve the problems in the prior art, avoid transmission conflicts, ensure that access to an unlicensed wireless channel is reserved for its own transmission, provide good communication performance, and / or provide high reliability.

[0041] Figure 4 A resource selection method 410 for back-to-back transmission in SL communication performed by a UE provided by an embodiment of the present disclosure is shown. In some embodiments, the method 410 includes: box 412, the higher layer of the UE triggers the first layer of the UE to perform a resource selection process based on one or more parameters to report the remaining candidate resource sets, the one or more parameters are provided by the higher layer, and the remaining candidate resource sets include at least one resource set in a continuous time slot. In some examples, the first layer refers to the layer 1 (L1) / PHY layer. In some examples, the higher layer refers to the MAC layer. This can solve the problems in the prior art, avoid transmission conflicts, ensure that access to unlicensed wireless channels is reserved for its own transmission, provide good communication performance, and / or provide high reliability.

[0042] In some embodiments, one or more parameters provided by the higher layer include: channel access priority class (CAPC) level, time length of MCSt or number of consecutive time slots, MCSt selection is enabled / disabled, SL HARQ feedback is enabled / disabled, L1 priority of physical sidelink shared channel (PSSCH) and its associated physical sidelink control channel (PSCCH) transmission, number of SL resource subchannels, and / or packet delay budget (PDB) or remaining PDB. In some embodiments, the first layer reports the remaining candidate resource set to the higher layer, including: the first layer performing SL listening, the first layer initializing the candidate resource set, and the first layer excluding resources from the candidate resource set based on one or more parameters provided by the higher layer.

[0043] In some embodiments, the resource selection process performed by the first layer includes a first stage of a resource exclusion process, and the first stage of the resource exclusion process includes: the first layer excludes resources from the remaining candidate resource set based on one or more of the following conditions and on a time slot level: the UE's own SL PSSCH / PSCCH and / or UL transmission, sidelink synchronization signal block (S-SSB) sending and / or receiving timing / time slot, time slot configured with physical sidelink feedback channel (PSFCH) resources, and / or time used to perform type 1 channel access process.

[0044] In some embodiments, the resource selection process performed by the first layer also includes a second stage of a resource exclusion process. The second stage of the resource exclusion process includes: the first layer excludes resources from the remaining candidate resource sets based on the measured reference signal received power (RSRP) and the resource reservation information and priority received in the sidelink control information (SCI) and on a resource level basis. In some embodiments, in the second stage of the resource exclusion process, if the number of consecutive candidate resource sets remaining after the resource level-based resource exclusion process does not meet one or more of the following criteria, the RSRP threshold level is increased and the first and second stages of the resource exclusion process are repeated. In some embodiments, the RSRP threshold level is increased until one or more of the following criteria are met: at least one consecutive candidate resource set remains in the remaining candidate resource sets, at least Y consecutive candidate resource sets remain in the remaining candidate resource sets, and / or the number of consecutive candidate resource sets remaining in the remaining candidate resource sets is at least X% of the total number of consecutive candidate resource sets. In some embodiments, the value of Y and / or the value of X% are preconfigured, predefined and / or provided by a higher layer.

[0045] In some embodiments, the method further includes: the higher layer selects MCSt resources from the remaining candidate resource sets for PSSCH / PSCCH transmission. In some embodiments, when more than one consecutive candidate resource sets are reported to the higher layer, the higher layer performs selection in the consecutive candidate resource sets according to one or more of the following criteria: no overlap with the time slots of its own SL and / or UL transmissions, no overlap with the additional / extra time required to complete the type 1 channel access process, prioritizing the resource sets that are earlier or earliest in time in consecutive time slots, prioritizing the selection of consecutive time slot resource sets that are just before or after the resources reserved by another UE, and / or when SL-HARQ feedback is enabled or SL-HARQ feedback is associated with the logical channel of the media access control packet data unit (MAC PDU) / TB, a time gap is required between multiple / adjacent transmissions of MCSt.

[0046] In the present disclosure of an inventive exemplary method for resource selection of MCSt in SL communications, the exemplary method provides an efficient way of selecting resources for a UE operating in SL resource allocation mode 2, which ensures that there is at least one set of candidate resources that are continuous in a time slot for transmitting one or more MAC PDU / TB in a PSSCH and an associated PSCCH. By ensuring that SL transmissions are continuous in a time slot (i.e., no empty / gap slots are left between consecutive time slots), it helps to keep access to the radio channel from being taken over by devices of another radio access technology (RAT) (such as Wi-Fi, NR-U, or LAA) when SL is operating in an unlicensed spectrum. In addition, by performing SL listening by the UE for possible resource reservations from other SL UEs, this operation avoids conflicts with other SL transmissions in the same channel and resource pool by excluding reserved resources from the candidate resource set for selection. The proposed exemplary resource selection method also excludes resources in time slots where the TX UE has its own transmissions (such as S-SSB, PSFCH, other PSSCH / PSCCH and / or UL transmissions) to ensure that the remaining candidate resources are not interrupted / separated by other signals or channels.

[0047] In addition, the proposed exemplary resource selection method takes into account the timing requirements in SL-HARQ feedback by ensuring that sufficient time gaps are provided between multiple MCSt transmissions. Finally, the proposed exemplary resource selection method is also compatible with the operation and COT sharing of multiple start symbols within a time slot, which is a new feature introduced to enable and enhance SL operation in unlicensed spectrum.

[0048] A detailed description of the resource selection method for MCSt in SL communication is provided below.

[0049] Resource (re)selection process in L1 / PHY layer

[0050] In order to ensure that there is at least one set of candidate resources continuous in the time slot for MCSt and that the selection of resources can avoid conflicts with transmissions from other UEs in the same resource pool, the proposed exemplary resource (re)selection method includes the UE higher layer triggering the L1 / PHY layer to initiate a resource selection process to report the available candidate resource sets, from which the higher layer can select MCSt resources for PSSCH / PSCCH transmission of one or more MAC PDUs or TBs.

[0051] To trigger the resource selection process in the L1 / PHY layer, in time slot n, the higher layer provides at least one or more of the following parameters.

[0052] CAPC level (p) used for PSSCH and its associated PSCCH transmissions. The UE L1 / PHY layer may use this information to determine the length of the MCSt and / or the number of additional resource slots that can be excluded from the candidate resource set.

[0053] Length of MCSt / number of consecutive time slots (eg, 2, 3, 4, ..., 40 time slots) This parameter is used to indicate the minimum number of consecutive time slots in reporting one or more candidate resource sets for MCSt.

[0054] MCSt selection is enabled / disabled. As an alternative to the above-mentioned higher layer parameter "MCSt length / number of consecutive time slots", the UE L1 / PHY layer is able to derive / determine this information based on SL CAPC(p). For example, when p=1, 2, 3 and 4, for 15kHz sub-carrier spacing (SCS), the length of MCSt / the number of time slots consecutive in time can be 2, 4, 6 or 10. When p=1, 2, 3 and 4, for 30kHz subcarrier spacing (SCS), the length of MCSt / the number of time slots consecutive in time can be 4, 8, 12 or 20. When p=1, 2, 3 and 4, for 60kHz subcarrier spacing (SCS), the length of MCSt / the number of time slots consecutive in time can be 8, 16, 24 or 40. As another method, the maximum COT duration (T slmcot,p) can be (pre)configured, predefined or provided by a higher layer. For example, if Z=50 and SCS is 15kHz, it means that for SL CAPC p=3, the length of MCSt / the number of consecutive time slots can be determined as 3 time slots. For another example, if Z=50 and SCS is 30kHz, it means that for SLCAPC p=2, the length of MCSt / the number of consecutive time slots can be determined as 4 time slots.

[0055] SL-HARQ feedback is enabled / disabled. This information is useful in ensuring that there is enough gap between two MCSt transmissions.

[0056] L1 priority for PSSCH and its associated PSCCH transmissions. During the resource exclusion phase / step, it is necessary to determine whether reserved resources from another UE can be excluded from the set of candidate resources by comparing the RSRP threshold level associated with this L1 priority for transmission with the L1 priority of the reserved resources.

[0057] The number of SL resource subchannels. This information is used to determine the size of candidate resources that can be reported to higher layers.

[0058] PDB or remaining PDB. This information is needed to determine the maximum time length or end point / completion time of the selection window.

[0059] In the above embodiment, in order to avoid transmission conflicts with other SL UEs operating in the same resource pool, the UE is able to perform blind decoding on the SCI transmitted in the PSCCH within the listening window to obtain reservation information of future resources from other UEs. In addition, the UE is able to measure the sidelink RSRP level of the decoded SCI to determine whether it is necessary to exclude the associated resources reserved in the SCI from the candidate resource set during the resource exclusion process / step.

[0060] Based on the above information provided by higher layers, the next step is to determine / initialize the set of all possible candidate resources within the resource selection window. Figure 5 An exemplary resource selection method for MCSt in SL communication provided by an embodiment of the present disclosure is shown. The set is represented as S A And define the resource selection window as [n+T1,n+T2], as in Figure 5 100, where the resource selection process is triggered in time slot n 101 and resources can be selected before the end of PDB 104. T1 is selected based on the SCS of the SL bandwidth part to take into account the time required to encode PSSCH / PSCCH before transmission. The higher the SCS for the SL bandwidth part, the larger the number of time slots used for T1. Then, the set SA Initialized to all possible candidate resources within the resource selection window, each candidate resource has a size according to the "number of SL resource subchannels" parameter provided by higher layers.

[0061] For the resource exclusion process, it can be divided into 2 stages, the first stage for excluding candidate resources based on one or more conditions and at a time slot level granularity (i.e., for the entire time slot), and the second stage for excluding candidate resources within a time slot at a resource level granularity based on resource reservations from other UEs.

[0062] The first stage of resource exclusion process (exclusion at time slot level)

[0063] During the first phase of the resource exclusion process, the intention is to exclude entire time slots of candidate resources due to the infeasibility of the UE utilizing these time slots.Some infeasibility issues may include one or more of the following areas.

[0064] Half-duplex problem caused by its own SL PSSCH / PSCCH and / or UL transmission. When the UE is triggered to select resources for MCSt, the UE may have previously selected some SL resources for transmitting other MAC PDUs or TBs. If one of these pre-selected or reserved resources falls into / is located in the resource selection window for MCSt, the resources in the entire time slot can be removed from the candidate resource set S A , because it is not expected that the UE will perform simultaneous transmission for two or more SLMAC PDUs / TBs in the same time slot. Similarly, if the UE has a resource that falls within the resource selection window or matches the candidate resource set S A Any UL transmission that overlaps with the duration of the resource can be selected from the candidate resource set S A Candidate resources in overlapping time slots are excluded from Figure 5 100 exemplarily shows that a UE has a scheduled UL transmission in time slot m and has a pre-selected / reserved resource 106 in time slot j, and the UE can select from a set of candidate resources S A The entire time slot resources 105 and 107 in time slot m and time slot j, respectively, are excluded from MCSt because these time slots are not available for MCSt.

[0065] S-SSB opportunities / slots (including both TX and RX opportunities / slots). Due to the same half-duplex and simultaneous transmission issues mentioned above, it is also possible to exclude those falling / located within the resource selection window and / or with the candidate resource set S A Overlapping S-SSB slots for both transmission and reception.

[0066] (Pre)configured time slots with PSFCH resources. In the existing SL frame structure, when PSFCH resources are (pre)configured in the resource pool, symbol indices 11, 12, and 13 in a time slot with 14 symbols are reserved for PSFCH transmission. Since these symbols cannot be used for PSSCH, they become large transmission gaps in MCSt and potentially cause the UE to lose access to the unlicensed channel if no other UE also transmits PSFCH in these symbols. Therefore, the candidate resource set S can be selected. A SL time slots with PSFCH resources (pre-)configured in the resource pool are excluded.

[0067] The processing time of the Type 1 channel access procedure. This is the additional time required to perform the Type 1 channel access procedure at the UE to access the shared channel. The processing time may include at least the corresponding SL CAPC level (CW max,p ). For example, in 15kHz SCS, the maximum allowable processing time T1 for encoding PSSCH / PSCCH before transmission is 3 time slots (3ms). If the SL CAPC level provided for PSSCH / PSCCH transmission is p=3 or p=4, the maximum contention window size for Type 1 channel access procedure will be about 9.2ms. Assuming that T1 processing time is also available for Type 1 channel sensing, it can also be selected from the set S A The first 6 to 7 time slots (after n+T1) of the candidate resources of the resource selection window are excluded from the resource selection window. Alternatively, this processing time for type 1 channel sensing can be processed / excluded by a higher layer (ie, MAC layer) during the final resource selection.

[0068] The second stage of the resource exclusion process (exclusion at the resource level)

[0069] During the second phase of the resource elimination process, the intention is to select from the candidate resource set S A The UE excludes resources that overlap with the reserved resources of other UEs (i.e., indicated in the received SCI) to avoid transmission conflicts. To this end, the UE compares the measured RSRP of the reserved resources with the RSRP threshold according to the priority level of the reserved resources and the priority level of the expected SL transmission. If the measured RSRP of the reserved resources is higher than the RSRP threshold, the UE selects the reserved resources from the candidate resource set S. A Exclude all candidate resources that overlap with reserved resources.

[0070] However, when selecting the candidate resource set S A After excluding overlapping resources, the candidate resource set S AThe remaining candidate resources in may be insufficient or unavailable for MCSt. For example, the remaining available candidate resources are discontinuous in the time slot and scattered in the resource pool. In order to ensure that the remaining candidate resource set S to be reported to the higher layer A Can be used for MCSt, in the candidate resource set (S A ) After initially excluding the indicated / reserved resources, if there are no contiguous candidate resource sets S remaining in the candidate resource set A , the RSRP threshold level is increased (eg, by 3 dB) until at least one of the following criteria is met.

[0071] There is at least one continuous candidate resource set S remaining in the candidate resource set A (ie, the resource selection window). Figure 5 100, the remaining candidate resources 108, 109, 110 and 111 in consecutive time slots k, k+1, k+2 and k+3, respectively, constitute a set of consecutive candidate resources that can be used for MCSt when the required length of MCSt is 4. It should be noted that the frequency position / location (i.e., subchannel index) of the remaining candidate resources in each time slot does not need to be the same for MCSt in order to maintain access to the unlicensed channel.

[0072] In the candidate resource set S A At least Y consecutive candidate resource sets remain.

[0073] Candidate resource set S A The number of the remaining consecutive candidate resource sets in is at least X% of the total number of the consecutive candidate resource sets.

[0074] The values ​​of Y and X% may be (pre)configured, predefined and / or provided by a higher layer of the UE. The UE then assigns the candidate resource S A The remaining set of candidate resources in is reported to higher layers for final selection of resources for MCSt, which is a subset of the candidate resources initialized before the resource elimination process.

[0075] Resource (re)selection process in higher layers (MAC layer)

[0076] Once the UE L1 / PHY layer reports the remaining candidate resource set S A , the UE MAC layer performs the final selection of the continuous resources in the time slot for MCSt. As mentioned above, the UE L1 / PHY layer can report the candidate resource set S A In the case where only one set is reported, the MAC layer selects a unique set of continuous time slot resources that meets the required length of MCSt.

[0077] For the case where more than one set of consecutive candidate resources is reported, the UE MAC layer may perform selection between the sets based on one or more of the following criteria to further enhance the performance of SL communications.

[0078] If not already done at the L1 / PHY layer, timeslots due to own SL (e.g., PSSCH / PSCCH, S-SSB, PSFCH) and / or UL transmissions are excluded. As mentioned previously, resources within timeslots of other SL and / or UL transmissions from the UE may also be excluded from selection. If this exclusion is not done at the UE L1 / PHY layer, these timeslots may be excluded / considered during the final selection of resources in the MAC layer.

[0079] As also mentioned before, the time required to perform the Type 1 channel access procedure may take longer than the T1 time to encode the PSSCH / PSCCH for transmission, especially for CAPC levels p=3 and p=4. Therefore, if the L1 / PHY layer has not completed during the resource exclusion step, it may exclude / not select time slots that may be located within the additional time (e.g., the reported candidate resource set S A This additional / extra time required to complete the Type 1 channel access procedure can be taken into account by using resources in the MAC layer in the first few time slots of the channel.

[0080] During the final selection of resources in the MAC layer, the earlier or earliest resource sets in consecutive time slots are prioritized. First, by transmitting the MAC PDU / TB earlier in time, it helps to reduce the delay in delivering data information to the receiving UE and thus improve the overall performance and user experience. Second, since there is no guarantee that any LBT channel access process can succeed every time, if the UE experiences an LBT failure when trying to access an unlicensed channel earlier in time, the UE has more opportunities to perform reselection of resources within the remaining PDB.

[0081] Prioritize the selection of a set of consecutive time slot resources just before or after the resources reserved by a different UE with which the TX-UE intends to share its COT. For example, in a unicast communication between only two SL UEs, it is beneficial for either of the UEs to select resources just before the reserved resources / scheduled transmission of the other UE so that the COT initiated by the earlier transmitting UE can be shared with the later UE to improve the success of channel access. In addition, this can also help with the half-duplex problem common in unicast communications, in which two UEs cannot receive each other's data messages when both are transmitting at the same time. By selecting resources just after the transmission of the other UE, an opportunity is created for the TX-UE to use the COT shared by the other / earlier UE.

[0082] When SL-HARQ feedback is enabled or SL-HARQ feedback is associated with the logical channel of MAC PDU / TB, ensure sufficient time gaps between multiple / adjacent transmissions of MCSt. A When multiple consecutive candidate resource sets are reported in the MAC PDU / TB and the MAC PDU / TB is associated with SL-HARQ feedback (i.e., SL-HARQ feedback is enabled and the receiving UE is required to provide SL-HARQ feedback in the PSFCH), the MAC layer may have the ability to select more than one consecutive time slot resource set for multiple MCSt transmissions for the same MAC PDU / TB. In this case, the UE MAC layer can ensure that there are sufficient time gaps between multiple MCSt transmission instances to allow SL-HARQ feedback in the PSFCH.

[0083] Figure 6 An exemplary resource selection method for MCSt when sidelink hybrid automatic repeat request (SL-HARQ) feedback is enabled is shown in the embodiment of the present disclosure. Figure 6 As shown in the diagram 200, when multiple MCSt resource sets 201, 202, 203 are selected, the UE MAC layer can ensure that there is a minimum time gap of at least "a" time slots (204) from the end of the MCSt to the corresponding PSFCH opportunity for SL-HARQ feedback and / or there is a minimum time gap of at least "b" time slots (205) between the SL-HARQ feedback PSFCH opportunity and the start of the next MCSt. The minimum time gap of "a" time slots is for the receiving UE to decode the PSSCH / PSCCH and prepare the SL-HARQ feedback information. If NACK is received in the PSFCH, the minimum time gap of "b" time slots is for the TX-UE to encode and prepare the PSSCH / PSCCH for MCSt.

[0084] Figure 7A resource selection method for back-to-back transmission in SL performed by a UE provided by an embodiment of the present disclosure is shown. In some embodiments, the method includes: a step in which the higher layer of the UE triggers the first layer of the UE to perform a resource selection process based on one or more parameters to report the remaining candidate resource sets, wherein the one or more parameters are provided by the higher layer, and the remaining candidate resource sets include at least one resource set in consecutive time slots; a step in the first stage of the resource exclusion process, wherein the first stage of the resource exclusion process includes the first layer excluding resources from the remaining candidate resource sets based on the time slot level according to one or more of the following conditions: the UE's own SL PSSCH / PSCCH and / or UL transmission, S-SSB transmission and / or reception timing / time slot, time slot configured with PSFCH resources, and / or time for performing type 1 channel access process; a step in the second stage of the resource exclusion process, wherein the second stage of the resource exclusion process includes the first layer excluding resources from the remaining candidate resource sets based on the measured RSRP and the resource reservation information and priority received in the SCI and based on the resource level; and a step in which the higher layer selects MCSt resources from the remaining candidate resource sets for PSSCH / PSCCH transmission. In some embodiments, when more than one continuous candidate resource set is reported to a higher layer, the higher layer performs selection among the continuous candidate resource sets according to one or more of the following criteria: no overlap with the time slot of its own SL and / or UL transmission, no overlap with the additional / extra time required to complete the type 1 channel access process, prioritizing the resource sets that are earlier or earliest in time in the continuous time slots, prioritizing the selection of the continuous time slot resource sets that are just before or after the resources reserved by another UE, and / or when SL-HARQ feedback is enabled or SL-HARQ feedback is associated with the logical channel of the MAC PDU / TB, time gaps are required between multiple / adjacent transmissions of MCSt. In some examples, the first layer refers to the layer 1 (L1) / PHY layer of the UE. In some examples, the higher layer refers to the MAC layer. This can solve problems in the prior art, avoid transmission conflicts, ensure that access to unlicensed wireless channels is reserved for its own transmissions, provide good communication performance, and / or provide high reliability.

[0085] Figure 8A UE 800 for wireless communication provided by an embodiment of the present disclosure is shown. The UE 800 includes a first layer 801 and a higher layer 802 coupled to the first layer. The higher layer 802 is configured to trigger the first layer 801 to perform a resource selection process based on one or more parameters to report the remaining candidate resource sets, the one or more parameters being provided by the higher layer 802, and the remaining candidate resource sets including at least one resource set in a continuous time slot. In some examples, the first layer 801 refers to the L1 / PHY layer. In some examples, the higher layer 802 refers to the MAC layer. In the above embodiment, the UE 800 is configured to perform the above method. This can solve the problems in the prior art, avoid transmission conflicts, ensure that access to unlicensed wireless channels is reserved for its own transmission, provide good communication performance, and / or provide high reliability.

[0086] The commercial benefits of some embodiments are as follows. 1. Solve the problems in the prior art. 2. Avoid transmission conflicts. 3. Ensure that access to unlicensed wireless channels is reserved for its own transmission. 4. Provide good communication performance. 5. Provide high reliability. 6. Some embodiments of the present disclosure are used by 5G-NR chipset suppliers, V2X communication system development suppliers, automobile manufacturers including cars, trains, trucks, buses, bicycles, motorcycles, helmets, etc., drones (unmanned aerial vehicles), smartphone manufacturers, smart watches, wireless headphones, wireless headsets, communication devices, remote control vehicles and robots for public safety purposes, AR / VR (augmented reality / virtual reality) device manufacturers for games, conferences / seminars, educational purposes, smart home appliances including TV, stereo, speakers, lights, doorbells, locks, cameras, conference headsets, etc., smart factory and warehouse equipment including IIoT (industrial Internet of Things) devices, robots, robotic arms, and simply used only between production machines. In some embodiments, commercial interest in the disclosed applications and commercial importance include that reduced power consumption for wireless communications means longer operating time of the device and / or better user experience and product satisfaction due to longer operating time between battery charges. Some embodiments of the present disclosure are combinations of "techniques / processes" that can be adopted in 3GPP specifications to create a final product. Some embodiments of the present disclosure relate to mobile cellular communication technologies in 3GPP NR Release 17, 18 and above for providing direct D2D wireless communication services.

[0087] Fig. 97 is a block diagram of an exemplary system 700 for wireless communication provided by an embodiment of the present disclosure. The embodiments described herein may be implemented in a system using any appropriately configured hardware and / or software. Fig. 9 A system 700 is shown, which includes a radio frequency (RF) circuit 710, a baseband circuit 720, an application circuit 730, a memory / storage device 740, a display 750, a camera 760, a sensor 770, and an input / output (I / O) interface 780 coupled to each other as shown.

[0088] Application circuitry 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (such as graphics processors, application processors). The processor may be coupled to a memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system.

[0089] The baseband circuit 720 may include circuits such as, but not limited to, one or more single-core or multi-core processors. The processor may include a baseband processor. The baseband circuit may have various radio control functions for implementing communication with one or more radio networks via RF circuits. The radio control functions may include, but are not limited to, signal modulation, encoding, decoding, radio frequency shifting, etc. In some embodiments, the baseband circuit may provide communications compatible with one or more radio technologies. For example, in some embodiments, the baseband circuit may support communications with an evolved universal terrestrial radio access network (EUTRAN) and / or other wireless metropolitan area networks (WMAN), wireless local area networks (WLAN), and wireless personal area networks (WPAN). An embodiment in which the baseband circuit is configured to support radio communications of more than one wireless protocol may be referred to as a multi-mode baseband circuit.

[0090] In various embodiments, baseband circuitry 720 may include circuitry that operates with signals that are not strictly considered to be in baseband frequencies. For example, in some embodiments, baseband circuitry may include circuitry that operates with signals having intermediate frequencies that are between baseband frequencies and radio frequencies.

[0091] RF circuitry 710 may enable communication with a wireless network using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry may include switches, filters, amplifiers, etc. to facilitate communication with a wireless network.

[0092] In various embodiments, RF circuitry 710 may include circuitry that operates with signals that are not strictly considered to be in radio frequencies. For example, in some embodiments, RF circuitry may include circuitry that operates with signals having intermediate frequencies that are between baseband frequencies and radio frequencies.

[0093] In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to a user equipment, eNB, or gNB may be embodied in whole or in part in one or more of the RF circuitry, baseband circuitry, and / or application circuitry. As used herein, "circuitry" may refer to, may be a part of, or may include an ASIC, electronic circuitry, processor (shared, dedicated, or group) and / or memory (shared, dedicated, or group) executing one or more software or firmware programs, combinatorial logic circuitry, and / or other suitable hardware components that provide the functionality described. In some embodiments, electronic device circuitry may be implemented in one or more software or firmware modules, or the functionality associated with the circuitry may be implemented by one or more software or firmware modules.

[0094] In some embodiments, some or all of the components of the baseband circuit, application circuit and / or memory / storage device may be implemented together on a system on a chip (SOC).

[0095] The memory / storage device 740 can be used to load and store data and / or instructions for the system, for example. The memory / storage device for one embodiment can include any combination of suitable volatile memory (such as dynamic random access memory (DRAM)) and / or non-volatile memory (such as flash memory).

[0096] In various embodiments, I / O interface 780 may include one or more user interfaces designed to implement interaction between a user and the system and / or a peripheral component interface designed to implement interaction between a peripheral component and the system. The user interface may include, but is not limited to, a physical keyboard or keypad, a touchpad, a speaker, a microphone, etc. The peripheral component interface may include, but is not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, and a power interface.

[0097] In various embodiments, the sensor 770 may include one or more listening devices to determine environmental conditions and / or location information related to the system. In some embodiments, the sensor may include, but is not limited to, a gyroscope sensor, an accelerometer, a proximity sensor, an ambient light sensor, and a positioning unit. The positioning unit may also be part of or interact with the baseband circuit and / or RF circuit to communicate with components of a positioning network (e.g., a global positioning system (GPS) satellite).

[0098] In various embodiments, the display 750 may include a display such as a liquid crystal display and a touch screen display. In various embodiments, the system 700 may be a mobile computing device, such as but not limited to a laptop computing device, a tablet computing device, a netbook, an ultrabook, a smart phone, AR / VR glasses, etc. In various embodiments, the system may have more or fewer components and / or different architectures. Where appropriate, the methods described herein may be implemented as a computer program. The computer program may be stored on a storage medium, such as a non-transitory storage medium.

[0099] Those skilled in the art will appreciate that each of the units, algorithms, and steps described and disclosed in the embodiments of the present disclosure is implemented using electronic hardware or a combination of software and electronic hardware for a computer. Whether a function is run in hardware or software depends on the application conditions and design requirements of the technical solution.

[0100] A person skilled in the art may use different methods to implement the functions of each specific application, and such implementations shall not exceed the scope of the present disclosure. A person skilled in the art may understand that since the working processes of the above-mentioned systems, devices, and units are substantially the same, reference may be made to the working processes of the systems, devices, and units in the above-mentioned embodiments. For ease of description and simplicity, these working processes will not be described in detail.

[0101] It is understood that the disclosed systems, devices and methods in the embodiments of the present disclosure can be implemented in other ways. The above embodiments are exemplary only. The division of units is based only on logical functions, and other divisions exist in the implementation. Multiple units or components can be combined or integrated in another system. It is also possible to omit or skip some features. On the other hand, the mutual coupling, direct coupling or communication coupling shown or discussed is operated indirectly or communicatively in an electrical, mechanical or other form through some ports, devices or units.

[0102] The units used as separate components for explanation may be physically separated or not physically separated. The units used for display may be physical units or not physical units, i.e. located in one place or distributed on multiple network units. Some or all of the units are used according to the purpose of the embodiment. In addition, each functional unit in each embodiment may be integrated into a physically independent processing unit, or may be integrated into one processing unit with two or more units.

[0103] If the software functional unit is implemented, used and sold as a product, it can be stored in a readable storage medium in a computer. Based on this understanding, the technical solution proposed in the present disclosure can be basically or partially implemented in the form of a software product. Alternatively, a part of the technical solution that is beneficial to traditional technology can be implemented in the form of a software product. The software product in the computer is stored in a storage medium, which includes multiple commands for a computing device (such as a personal computer, a server or a network device) to run all or some of the steps disclosed by the embodiments of the present disclosure. The storage medium includes a USB disk, a mobile hard disk, a ROM, a RAM, a floppy disk or other types of media capable of storing program code.

[0104] While the present disclosure has been described in connection with what is considered to be the most practical and preferred embodiment, it is to be understood that the disclosure is not limited to the disclosed embodiment, but is intended to cover various arrangements made without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. A resource selection method, characterized in that: The method is used for back-to-back transmission in a sidelink (SL) communication performed by a user equipment (UE), and the method comprises: The higher layer of the UE triggers the first layer of the UE to perform a resource selection process based on one or more parameters to report the remaining candidate resource sets, wherein the one or more parameters are provided by the higher layer, and the remaining candidate resource sets include at least one resource set in consecutive time slots.

2. The method according to claim 1, characterized in that The one or more parameters provided by the higher layer include: Channel access priority CAPC level; The time length of the multi-continuous time slot transmission MCSt or the number of consecutive time slots; MCSt selection is enabled / disabled; SL hybrid automatic repeat request HARQ feedback is enabled / disabled; L1 priority of Physical Sidelink Shared Channel PSSCH and its associated Physical Sidelink Control Channel PSCCH transmissions; The number of SL resource subchannels; and / or Packet delay budget PDB or remaining PDB.

3. The method according to claim 1 or 2, characterized in that: The first layer reporting the remaining candidate resource sets to the higher layer includes: the first layer performing SL listening, the first layer initializing the candidate resource set, and the first layer excluding resources from the candidate resource set based on the one or more parameters provided by the higher layer.

4. The method according to any one of claims 1 to 3, characterized in that The resource selection process performed by the first layer includes a first stage of a resource exclusion process, the first stage of the resource exclusion process comprising: the first layer excludes resources from the remaining set of candidate resources based on one or more of the following conditions and on a time slot level basis: UE's own SL physical sidelink shared channel PSSCH / physical sidelink control channel PSCCH and / or uplink UL transmission; Sidelink synchronization signal block S-SSB transmission and / or reception opportunity / time slot; A time slot configured with a physical sidelink feedback channel PSFCH resource; and / or Time used to perform Type 1 channel access procedure.

5. The method according to claim 4, characterized in that The resource selection process performed by the first layer also includes a second stage of the resource exclusion process, and the second stage of the resource exclusion process includes: the first layer excludes resources from the remaining candidate resource set based on the measured reference signal received power RSRP and the resource reservation information and priority received in the side link control information SCI and on a resource level basis.

6. The method according to claim 5, characterized in that In the second phase of the resource exclusion process, if the number of consecutive candidate resource sets remaining after the resource level-based resource exclusion process does not meet one or more of the following criteria, the RSRP threshold level is increased and the first and second phases of the resource exclusion process are repeated.

7. The method according to claim 6, characterized in that The RSRP threshold level is increased until one or more of the following criteria are met: At least one continuous candidate resource set remains in the remaining candidate resource sets; At least Y consecutive candidate resource sets remain in the remaining candidate resource sets; and / or The number of the remaining contiguous candidate resource sets in the remaining candidate resource sets is at least X% of the total number of the contiguous candidate resource sets.

8. The method according to claim 7, characterized in that The value of Y and / or the value of X% are preconfigured, predefined and / or provided by the higher layer.

9. The method according to any one of claims 1 to 8, characterized in that The method further comprises: The higher layer selects multiple consecutive time slot transmission MCSt resources from the remaining candidate resource set for physical sidelink shared channel PSSCH / physical sidelink control channel PSCCH transmission.

10. The method according to claim 9, characterized in that When more than one set of contiguous candidate resources is reported to the higher layer, the higher layer performs selection among the sets of contiguous candidate resources according to one or more of the following criteria: Does not overlap with the time slot of its own SL and / or UL transmission; Does not overlap with the additional / extra time required to complete the Type 1 channel access procedure; prioritizing a temporally earlier or earliest set of resources in consecutive time slots; Prioritizing selection of a set of contiguous time slot resources that immediately precedes or follows resources reserved by another UE; and / or When SL-HARQ feedback is enabled or SL-HARQ feedback is associated with a logical channel of a media access control packet data unit MAC PDU / transport block TB, a time gap is required between multiple / adjacent transmissions of MCSt.

11. A user equipment UE, characterized in that: The UE includes: A first layer and a higher layer coupled to the first layer, the higher layer being configured to trigger the first layer to perform a resource selection process based on one or more parameters to report a remaining set of candidate resources, wherein the one or more parameters are provided by the higher layer, and the remaining set of candidate resources includes at least one set of resources in consecutive time slots.

12. A user equipment UE, characterized in that: The UE includes: Memory; transceiver; and a processor coupled to the memory and the transceiver; The UE is configured to perform the method according to any one of claims 1 to 10.

13. A non-transitory machine-readable storage medium, characterized in that: The non-transitory machine-readable storage medium has instructions stored thereon that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 10.

14. A chip, characterized in that: The chip comprises: A processor, wherein the processor is configured to call and run a computer program stored in a memory so as to enable a device equipped with the chip to perform the method according to any one of claims 1 to 10.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which enables a computer to execute the method according to any one of claims 1 to 10.

16. A computer program product, characterized in that The computer program product comprises a computer program, which causes a computer to execute the method according to any one of claims 1 to 10.

17. A computer program, characterized in that The computer program causes a computer to execute the method according to any one of claims 1 to 10.

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