User equipment and resource selection method for sidewalk communication

Abstract

A resource selection method performed by a user equipment (UE) for sidewalk communication includes performing resource selection based on at least one of: selecting a resource in a continuous resource block (RB) set for sidewalk transmission; resources in different RB sets in the same time slot are prevented from being selected for simultaneous transmission; selecting resources in continuous time slots within the duration of channel occupancy time (COT) and within the same RB set; when the priority level of sidewalk transmission is equal to or higher than the COT self-initiated by the UE or the COT shared by other UE, preferentially considering or selecting resources for sidewalk transmission in the self-initiated COT or the shared COT and in the same RB set of the self-initiated COT or the shared COT; in one embodiment, channel busy rate (CBR) and / or channel occupancy rate (CR) measurements are made for each RB set, and based on the CBR and / or CR measurements, RB sets with lower load / congestion levels with lower measured CBR and / or CR values are preferentially considered or selected, among others.

Description

Technical Field

[0001] The present disclosure relates to the field of communication systems, and more particularly, to a user equipment (UE) and a resource selection method for sidelink communication, which can provide good communication performance and / or provide high reliability. Background Art

[0002] In the development process of direct radio wireless transmission and reception between devices (commonly known as device-to-device (D2D) communication), D2D communication was first developed by the 3rd generation partnership project (3GPP) and introduced in Release 12 (officially called sidelink communication), and improved for public safety emergency use cases (such as mission-critical communication) in Release 13, mainly for supporting low data rate and voice connections. In Releases 14, 15, and 16 of 3GPP, sidelink technology has been developed to further support vehicle-to-everything (V2X) communication, as part of the development of the global intelligent transportation system (ITS), thus improving road safety and promoting the development of advanced / autonomous driving use cases. To further expand sidelink technology to support a wider range of applications and devices with limited power / battery, in Release 17, the technology has been further enhanced in terms of energy saving and transceiver link reliability. In Release 18, 3GPP is currently seeking to evolve wireless technology and extend its operation to unlicensed spectrum, so that the available bandwidth for D2D communication using sidelink is larger, the data transmission rate is faster, and the market acceptance is higher, and any mobile network operator does not need to allocate and configure its large and valuable wireless spectrum for data services that do not use its mobile network.

[0003] Therefore, there is a need for a user equipment (UE) and a resource selection method for sidelink communication to solve the problems of the prior art, improve the success rate of accessing unlicensed / shared channels to transmit sidelink (SL) data information, avoid uneven wireless traffic load between different unlicensed / shared channels, reduce the peak-to-average power ratio (PAPR) problem of wireless transmission, improve the utilization rate of wireless resources, avoid frequency resource fragmentation, provide good communication performance, and / or provide high reliability. Summary of the Invention

[0004] In a first aspect of the present disclosure, a user equipment (UE) includes an actuator configured to perform resource selection based on at least one of the following: selecting resources in a consecutive resource block (RB) set for sidelink transmission; avoiding selecting resources in different RB sets in the same time slot for simultaneous transmission; selecting resources in consecutive time slots within the same RB set during a channel occupancy time (COT) duration; when the priority level of sidelink transmission is equal to or higher than a COT initiated by the UE itself or a COT shared by other UEs, preferentially considering or selecting resources for sidelink transmission within the self-initiated COT or the shared COT and in the same RB set as the self-initiated COT or the shared COT; measuring the channel busy ratio (CBR) and / or channel occupancy ratio (CR) for each RB set, and based on the CBR and / or CR measurement, preferentially considering or selecting an RB set with a lower load / congestion level having a smaller measured CBR and / or CR value; avoiding selecting or excluding resources of an entire RB set based on one or more historical listen-before-talk (LBT) failure reports or consecutive LBT failure judgments / indications; and preferentially considering or selecting resources in one or two edge RB sets in a resource pool.

[0005] In a second aspect of the present disclosure, a method for resource selection for sidelink communication performed by a UE includes the UE performing resource selection based on at least one of the following: selecting consecutive resources in an RB set for sidelink transmission; avoiding selecting resources in different RB sets in the same time slot for simultaneous transmission; selecting resources in consecutive time slots within the same RB set during a COT duration; when the priority level of sidelink transmission is equal to or higher than a COT initiated by the UE itself or a COT shared by other UEs, preferentially considering or selecting resources for sidelink transmission within the self-initiated COT or the shared COT and in the same RB set as the self-initiated COT or the shared COT; measuring the CBR and / or CR for each RB set, and based on the CBR and / or CR measurement, preferentially considering or selecting an RB set with a lower load / congestion level having a smaller measured CBR and / or CR value; avoiding selecting or excluding resources of an entire RB set based on one or more historical LBT failure reports or consecutive LBT failure judgments / indications; and preferentially considering or selecting resources in one or two edge RB sets in a resource pool.

[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 processor is configured to execute the above method.

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

[0008] In a fifth aspect of the present disclosure, a chip includes a processor that is 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 stores a computer program that causes a computer to execute the above method.

[0010] In a seventh aspect of the present disclosure, a computer program product includes a computer program that causes 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] To more clearly illustrate the embodiments of the present disclosure or related technologies, the following drawings will be briefly introduced in the embodiments. Obviously, the drawings are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings without any creative effort based on these drawings.

[0013] Figure 1 It is a block diagram of a user equipment (UE) communicating in a communication network system according to an embodiment of the present disclosure.

[0014] Figure 2 It shows a schematic diagram of a user plane protocol stack according to an embodiment of the present disclosure.

[0015] Figure 3 It shows a schematic diagram of a control plane protocol stack according to an embodiment of the present disclosure.

[0016] Figure 4 It shows a flowchart of a resource selection method for sidelink communication executed by a UE according to an embodiment of the present disclosure.

[0017] Figure 5 It shows a schematic diagram of one of the proposed resource selection methods for sidelink communication in an unlicensed spectrum band (SL-U) communication based on selected resources according to an embodiment of the present disclosure.

[0018] Figure 6A schematic diagram showing one of the proposed resource selection methods for SL-U communication based on selected resources according to an embodiment of the present disclosure.

[0019] Figure 7 A block diagram of a UE for wireless communication according to an embodiment of the present disclosure.

[0020] Figure 8 A block diagram of a wireless communication system according to an embodiment of the present invention. Detailed implementation manners

[0021] The technical matters, structural features, achieved objectives and effects of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Specifically, the terms used in the embodiments of the present disclosure are only for the purpose of describing the embodiments of the present disclosure and are not used to limit the present disclosure.

[0022] Unlicensed / shared spectrum

[0023] Traditionally, wireless fidelity (Wi-Fi) technology and Bluetooth wireless technology typically use the shared (also known as unlicensed) wireless spectrum in the 2.4 GHz band, 5 GHz band, and 6 GHz band for short-distance communication (from a few meters to dozens of meters). It is generally believed that the traffic carried on the unlicensed spectrum band is more than that on any other wireless band because anyone can use this spectrum for free / cost-free as long as the communication device complies with the specific technical specifications of each region. In addition to Wi-Fi and Bluetooth, other radio access technologies (RATs), such as licensed-assisted access (LAA) based on 4G-long-term evolution (LTE) in the 3rd generation partnership project (3GPP) and new radio unlicensed (NR-U) in the 5G-new radio unlicensed mobile system, also operate in the same unlicensed frequency band. To enable devices of different RATs (Wi-Fi, Bluetooth, LAA, NR-U, and other technologies) to operate simultaneously and coexist fairly in the same geographical area without causing serious interference and interruption to each other's transmissions, before any wireless transmission, a clear channel access (CCA) protocol is adopted, such as listen-before-talk (LBT) adopted in LAA and NR-U and carrier sense multiple access / collision avoidance (CSMA / CA) used in Wi-Fi and Bluetooth, to ensure that when there is already a radio transmitting on the same channel, other radios do not transmit.

[0024] To enable sidelink radio technology to operate on unlicensed frequency bands and coexist with existing RATs that are already operating on unlicensed frequency bands, an LBT-based solution can be adopted to ensure that there is no ongoing activity on the radio channel before attempting to access the channel for transmission. For example, if a sidelink user equipment (UE) successfully performs Class 1 LBT, the UE is entitled to access and occupy the unlicensed channel for a duration of the channel occupancy time (COT). This is called COT initiation. However, during the acquired COT, if the COT-initiation sidelink UE or the COT-response sidelink UE does not perform radio transmission during an idle time that exceeds a predefined length (e.g., 16 μs or 25 μs), a device of another RAT can still access the channel. Therefore, the access right to the channel may be lost before performing another successful LBT. A feasible solution to the problem of losing the access right to the channel may be back-to-back (B2B) transmission.

[0025] B2B transmission / multi-consecutive slots transmission (MCSt)

[0026] B2B transmission (also known as burst transmission or multi-consecutive time slot transmission) is mainly used to enable a sidelink (SL) communication UE to occupy an unlicensed channel for a longer time (i.e., more than one time slot), so as to reduce the risk that the unlicensed channel is accessed by a wireless transmission (Tx) device of another RAT. Such B2B transmission is particularly important and useful for an SL Tx-UE operating in the unlicensed radio spectrum, which has a large data transport block (TB) or media access control (MAC) packet data unit (PDU), requires multiple retransmissions, disables sidelink hybrid automatic repeat request (SL-HARQ) feedback, and / or has a short delay requirement (small packet delay budget (PDB)). When the unlicensed radio channel is busy / congested (e.g., many devices simultaneously attempt to access the channel for transmission), due to the random backoff timer and priority levels in the LBT process, it may be difficult to obtain access to the channel and it takes a long time. Therefore, when the UE finally has the opportunity to access the wireless channel within a COT length that may last for several milliseconds (e.g., 2 ms, 4 ms, 6 ms, or 10 ms), its purpose is to maintain channel access for as long as possible (e.g., the entire or most of the COT length) to send as much data as possible by continuously transmitting on this unlicensed channel, so that wireless devices of other RATs cannot access the channel.

[0027] Unlicensed Channel Access and Occupation

[0028] As described above, the UE can perform a Class 1 LBT process before any SL transmission, first obtain access to the unlicensed channel, and then initiate a COT. In addition, B2B transmission can be used to avoid large transmission gaps, thus retaining the COT and access to the channel. In addition to Class 1 LBT, the UE can also perform a Class 2 LBT during a COT or shared COT in accordance with the requirements of the unlicensed spectrum specification for gaps of 25 microseconds (μs) or less. For example, in Class 2A LBT, if the unlicensed channel is sensed to be idle for 25 μs or longer, the COT-initiating UE is allowed to resume its transmission, and / or the COT-sharing UE is allowed to start its transmission within the COT. In Class 2B LBT, the allowed transmission gap is 16 μs. Class 2C LBT (in which the UE does not need to perform channel sensing) is used for gaps less than 16 μs.

[0029] In the LAA and NR-U systems, due to the propagation delay of scheduling control information sent between gNB / gNB and UE, the UE's switch from the receiving mode (RX) to the transmitting mode (TX), and the encoding and modulation of the actually uplink (UL) transmitted data information, transmission gaps are inevitable / necessary before the UE occupies the unlicensed channel. Sometimes, these gaps can be greater than 25 μs, and the extension of the cyclic prefix (CP) can be transmitted first on the UL so that the unlicensed channel will not be taken over by other devices operating in the same frequency band due to excessive channel idle time. The duration of this cyclic prefix extension (CPE) transmitted on the UL is determined by the base station (gNB / eNB) so that there will be no access blocking / denial problems among different UEs, and this duration is indicated to each scheduled UE, which only needs to follow this indication and perform UL transmission accordingly.

[0030] In SL communication, especially in resource allocation (RA) mode 2, all transmission resources will be determined and selected by the UE itself without any intervention, assistance, and coordination from any base station to avoid transmission conflicts. In addition, the SL system supports frequency domain multiplexing (FDM) of transmissions from multiple UEs in the same time slot, thus maximizing the utilization of wireless resources and shortening the communication delay at the same time. However, since there is no base station control and assistance for the SL UE to access the unlicensed channel, even in RA mode 1 under gNB scheduling, the UE may attempt to access this channel at different times using different LBT channel access procedures with different channel idle period requirements. In this operating scenario, it is impossible to coordinate in advance multiple UEs transmitting on the same time slot to avoid being blocked / denied access to the unlicensed channel.

[0031] Channel access to multiple unlicensed / shared channels

[0032] Generally, for the unlicensed spectrum bands in the 5 GHz and 6 GHz frequency ranges (the target unlicensed bands for SL communication), the total bandwidth can be very large, reaching the order of hundreds of megahertz (MHz). According to the unlicensed frequency allocation plan, most countries / regions have at least 100 MHz of continuous bandwidth blocks available. For many applications, it is not necessary to use such a large bandwidth to transmit small data packets. Since the wireless transmission design of most RATs in the unlicensed spectrum is based on the time division multiplexing (TDM) scheme, where only one device transmits at a time, transmitting small data packets but occupying the entire bandwidth does not use the wireless frequency very efficiently. Therefore, the unlicensed spectrum band is divided into multiple smaller unlicensed / shared channels, and before a wireless transmission device transmits, it determines any number of the required unlicensed / shared channels and performs the LBT channel access procedure on the selected unlicensed / shared channels. Currently, since 20 MHz is the most commonly used bandwidth size and one of the smallest bandwidths adopted for unlicensed / shared channel access globally, 3GPP defines each unlicensed / shared channel with a 20 MHz bandwidth as the basic unit (a set of resource blocks; RB set) of the unlicensed band in LAA and NR-U for the eNB / gNB and UE to perform the LBT channel access procedure. This method also applies to SL communication on the unlicensed band. When a UE needs more than one unlicensed / shared channel (RB set) to transmit a large data packet, the UE needs to perform the LBT channel access procedure on each required and selected unlicensed channel / RB set separately. And only when all channel access procedures are successful can the UE access these channels / RB sets and be allowed to transmit the large data packet across the multiple channels / RB sets. If any one of the LBT channel access procedures fails (e.g., the channel is busy), the UE cannot transmit anything on the selected multiple channels / RB sets (i.e., even if the LBT channel access is successful on some channels / RB sets).

[0033] Mode 2 Resource Allocation Mechanism in Sidelink

[0034] In the design of existing SL communication resource allocation mechanisms, the mode 2 resource selection method relies on the SL transmitting UE to autonomously select resources from the SL resource pool for the transmission of its own data messages. In this method, the selection of transmission resources is not random, but is based on a sensing and reservation strategy to avoid conflicts with other SL transmitting UEs operating in the same resource pool. In this resource selection strategy, the transmitting UE senses the channel within a sensing window (different from the LBT channel sensing) to detect and decode the SL resource reservation information from other transmitting UEs. Based on the received resource reservation information, the UE does not select the reserved resources to avoid TX conflicts. Similarly, when the UE transmits data and control messages, the UE also issues / 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 reserved resources can be at most 31 time slots apart. Since it is not possible to guarantee the continuous selection of resources in time, this resource selection method is not ideal for MCSt.

[0035] In some embodiments, for the resource allocation method proposed for SL communication over one or more unlicensed / shared channels (RB sets), the Tx-UE pays more attention to the LBT channel access process and follows certain selection rules to select SL radio resources, thereby improving the access success rate of unlicensed / shared channels to send sidelink data information and avoiding uneven loading of wireless traffic (including transmissions from other RATs such as NR-U, Wi-Fi, etc.) between different unlicensed / shared channels. Using the proposed resource selection and channel access method for SL communication in this unlicensed spectrum also includes the following advantages.

[0036] A lower peak-to-average power ratio (PAPR) of wireless transmission means that the orthogonal frequency division multiplexing (OFDM) signal in 5G can reduce or avoid signal clipping when passing through a power amplifier. Therefore, the transmitted signal can be amplified more uniformly in the frequency domain without distortion and information loss.

[0037] It is possible to utilize more wireless resources available in the guard band (GB) physical resource blocks (PRBs) for SL transmissions that require one or more unlicensed / shared channels (RB sets).

[0038] Avoid frequency resource fragmentation, which does not allow the transmission of large TBs across multiple consecutive channels (RB sets) using the central unlicensed / shared channel.

[0039] Figure 1 In some embodiments, one or more UEs 10 (e.g., a first UE) and one or more UEs 20 (e.g., a second UE) communicating in a communication network system 30 according to embodiments 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 21 may be used to implement the functions, processes, and / or methods described in this specification. The radio interface protocol layer may be implemented in the processor 11 or 21. The memory 12 or 22 is operably coupled to the processor 11 or 21 and stores various information to operate the processor 11 or 21. The transceiver 13 or 23 is operably coupled to the processor 11 or 21 and transmits and / or receives radio signals.

[0040] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chip sets, logic circuits, and / or data processing devices. The memory 12 or 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 23 may include a baseband circuit for processing radio frequency signals. When the embodiments are implemented in software, the techniques described herein may be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described herein. These modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be implemented within the processor 11 or 21 or outside the processor 11 or 21, in which case the memory 12 or 22 may be communicatively coupled to the processor 11 or 21 in various ways known in the art.

[0041] Communication between UEs involves vehicle-to-everything (V2X) communication, including vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), and vehicle-to-infrastructure / network (V2I / N) based on sidelink technologies developed under LTE and NR Releases 17, 18, and higher of the 3rd generation partnership project (3GPP). UEs communicate directly with each other through sidelink interfaces such as the PC5 interface. Some embodiments of the present disclosure relate to sidelink communication technologies in 3GPP NR Release 17 and higher, for example, providing cellular-vehicle to everything (C-V2X) communication.

[0042] In some embodiments, UE 10 may be a sidelink packet TB Tx-UE. UE 20 may be a sidelink packet TB reception UE (Rx-UE) or a peer UE. The sidelink packet TB Rx-UE may be used to send ACK / NACK feedback to the packet TB Tx-UE. The peer UE 20 is another UE communicating with the Tx-UE 10 in the same SL unicast or multicast session.

[0043] Figure 2 An example user plane protocol stack according to an embodiment of the present disclosure is shown. Figure 2Illustrated are some embodiments where, in the user plane protocol stack, the service data adaptation protocol (SDAP), packet data convergence protocol (PDCP), radio link control (RLC) layer, and media access control (MAC) sublayer and physical (PHY) layer (also referred to as the first layer or layer 1 (L1)) can terminate at UE 10 and base station 40 (e.g., gNB) on the network side. In an example, the PHY layer provides a transmission service to higher layers (e.g., MAC, RRC, etc.). In an example, the services and functions of the MAC sublayer can include: mapping between logical channels and transport channels, multiplexing MAC service data units (SDUs) belonging to one or different logical channels into a transport block (TB) transmitted to the PHY layer or demultiplexing MAC SDUs belonging to one or different logical channels from the TB transmitted from the PHY layer, scheduling information reporting, error correction via HARQ (e.g., in the case of carrier aggregation (CA), there is one HARQ entity per carrier), priority handling between UEs via dynamic scheduling, priority handling between logical channels of a UE via logical channel priority, and / or padding. The MAC entity can support one or more numerologies and / or transmission timings. In an example, the mapping restrictions in logical channel priority can control which numerology and / or transmission timing a logical channel can use. In an example, the RLC sublayer can support transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM) transmission modes. The RLC configuration can be per logical channel and is independent of numerology and / or transmission time interval (TTI) duration. In an example, automatic repeat request (ARQ) can operate on any numerology and / or TTI duration configured for a logical channel.In an example, the services and functions of the PDCP layer for the user plane may include sequence numbering, header compression and decompression, transmission of user data, reordering and duplicate detection, PDCP PDU routing (e.g., in the case of a split bearer), retransmission of PDCP SDUs, encryption, decryption, and integrity protection, PDCP SDU discard, PDCP re-establishment and data recovery for RLC AM, and / or duplication of PDCP PDUs. In an example, the services and functions of SDAP may include mapping between QoS flows and data radio bearers. In an example, the services and functions of SDAP may include mapping the quality of service indicator (QFI) in downlink (DL) and uplink (UL) packets. In an example, the protocol entity of SDAP may be used for a separate PDU session.

[0044] Figure 3 Shows an example control plane protocol stack according to an embodiment of the present disclosure. Figure 2 Shows that in some embodiments, in the control plane protocol stack, where the PDCP, RLC, MAC sublayers, and PHY layer may terminate at the UE 10 and the base station 40 (e.g., gNB) on the network side, and perform the above-mentioned services and functions. In an example, RRC is used to control radio resources between the UE and the base station (e.g., gNB). In an example, RRC may terminate at the UE and the gNB on the network side. In an example, the services and functions of RRC may include broadcasting system information related to AS and NAS, paging initiated by 5GC or RAN, establishing, maintaining, and releasing the RRC connection between the UE and the RAN, security functions including key management, establishment, configuration, maintenance, and release of signaling radio bearer (SRB) and data radio bearer (DRB), mobility functions, QoS management functions, UE measurement reporting and reporting control, radio link failure detection and recovery, and / or non-access stratum (NAS) message transmission from the UE to the NAS or from the NAS to the UE. In an example, the NAS control protocol may terminate at the UE and the AMF on the network side, and may perform, for example, authentication, mobility management between the UE and the AMF for 3GPP access and non-3GPP access, and session management between the UE and the SMF for 3GPP access and non-3GPP access.

[0045] When a specific application is executed in the UE and the specific application requires data communication services, the application layer responsible for executing the specific application provides application-related information, i.e., application group / category / priority information / ID, to the NAS layer. In this case, the application-related information can be pre-configured / defined in the UE. (Alternatively, the application-related information is received from the network to be provided to the application layer from the AS (RRC) layer. When the application layer starts data communication services, the application layer requests the AS (RRC) layer to provide information to receive the information.)

[0046] In some embodiments, the processor 11 is configured to perform resource selection based on at least one of the following: select consecutive resources in an RB set for sidelink transmission; avoid selecting resources in different RB sets in the same time slot for simultaneous transmission; select resources in consecutive time slots within the same RB set during the COT duration; when the priority level of sidelink transmission is equal to or higher than the UE-initiated COT or the COT shared by other UEs, give priority to or select resources for sidelink transmission within the UE-initiated COT or the shared COT and in the same RB set as the UE-initiated COT or the shared COT; perform CBR and / or CR measurements on each RB set, and based on the CBR and / or CR measurements, give priority to or select the RB set with a lower load / congestion level with a smaller measured CBR and / or CR value; avoid selecting or excluding resources of an entire RB set based on one or more historical LBT failure reports or consecutive LBT failure judgments / indications; and give priority to or select resources in one or two edge RB sets in the resource pool. This can solve the problems in the prior art, improve the success rate of accessing the unlicensed / shared channel to send sidelink data information, avoid uneven wireless traffic load between different unlicensed / shared channels, reduce the wireless transmission PAPR problem, improve the wireless resource utilization rate, avoid frequency resource fragmentation, provide good communication performance, and / or provide high reliability.

[0047] Figure 4A resource selection method 410 for sidelink communication performed by a UE according to an embodiment of the present disclosure is shown. In some embodiments, method 410 includes: block 412, the UE performs resource selection based on at least one of the following: selecting resources in a continuous RB set for sidelink transmission; avoiding selecting resources in different RB sets in the same time slot for simultaneous transmission; within the COT duration and within the same RB set, selecting resources in continuous time slots; when the priority level of the sidelink transmission is equal to or higher than the self-initiated COT or the COT shared by other UEs, within the self-initiated COT or the shared COT and in the same RB set as the self-initiated COT or the shared COT, giving priority to or selecting resources for sidelink transmission; performing CBR and / or CR measurements on each RB set, and based on the CBR and / or CR measurements, giving priority to or selecting the RB set with a lower load / congestion level with a smaller measured CBR and / or CR value; based on one or more historical LBT failure reports or consecutive LBT failure judgments / indications, avoiding selecting or excluding resources of an entire RB set; and giving priority to or selecting resources in one or two edge RB sets in a resource pool. This can solve the problems of the prior art, improve the success rate of accessing unlicensed / shared channels to send sidelink data information, avoid uneven wireless traffic load between different unlicensed / shared channels, reduce the wireless transmission PAPR problem, improve wireless resource utilization, avoid frequency resource fragmentation, provide good communication performance, and / or provide high reliability.

[0048] In some embodiments, resources in a continuous RB set are selected for sidelink transmission of one or more resources that need to span more than one RB set, and / or the UE is used to utilize resources in the GB PRBs between the continuous RB sets. In some embodiments, selecting resources in different RB sets in the same time slot for sidelink transmission of the same or different MAC PDUs or TBs with a required resource size less than one RB set is avoided. In some embodiments, during the initial resource selection or reselection process of a MAC PDU or TB, resources are given priority to or selected for sidelink transmission within the self-initiated COT or the shared COT. In some embodiments, resources in one or two edge RB sets in a resource pool are given priority to or selected for transmission within a single RB set.

[0049] In some embodiments, when there are no available / candidate resources in adjacent RB sets, resources in one or two edge RB sets in the resource pool are preferentially considered or selected for transmission within a single RB set. In some embodiments, when resources in one or two edge RB sets in the resource pool are preferentially considered or selected, the available / candidate resource ratio of one or two edge RB sets in the resource pool is lower than a configured or predefined threshold. In some embodiments, the configured or predefined threshold is 70% or 80% of the available / candidate resources of one or two edge RB sets in the resource pool. In some embodiments, when resources in one or two edge RB sets in the resource pool are preferentially considered or selected, the available / candidate resource ratio of one or two edge RB sets in the resource pool is equal to or less than the available / candidate resource ratio of one or more central RB sets.

[0050] In some embodiments, when resources in one or two edge RB sets in the resource pool are preferentially considered or selected, the available / candidate resource ratio of one or two edge RB sets in the resource pool is greater than the available / candidate resource ratio of one or more central RB sets. In some embodiments, X% represents the available / candidate resource ratio of the edge RB set, Y% represents the available / candidate resource ratio of the central RB set, and the difference between X% and Y% is less than or equal to a configured or predefined value. In some embodiments, the configured or predefined value is equal to 20%.

[0051] In the above embodiments, the term "configured" may refer to "pre-configured" and "network configured". The term "predefined" or "predefined rule" in the present disclosure may be implemented by pre-storing corresponding codes, tables or other means for indicating relevant information in a device (e.g., including a UE and a network device), and the present disclosure does not limit its specific implementation manner. For example, "predefined" may refer to the content defined in the protocol. It should also be understood that in the present disclosure, "protocol" may refer to standard protocols in the communication field, such as may include LTE protocol, NR protocol, and relevant protocols applied in future communication systems, and the present disclosure does not limit this.

[0052] Example:

[0053] In some embodiments, for the new resource selection method for sidelink communication of the resource pool for spanning more than one unlicensed / shared channel (also referred to as an RB set in the 5G system) in the present disclosure, it is proposed that the SL Tx-UE perform resource selection in a more LBT-aware and rule-based manner to avoid signal distortion and traffic congestion problems in radio frequency (RF) transmission, and at the same time improve the access success rate of the unlicensed / shared channel, thereby achieving more reliable SL communication.

[0054] In the SL mode 2 resource allocation, as described above, the Tx-UE first performs a sensing process within the SL resource pool to detect and exclude the resources already reserved within the resource selection window (RSW). Then the remaining / available / unreserved resources are reported to the upper layer (i.e., the MAC layer) for finally selecting one or more resources for (re)transmitting the MAC PDU / TB. During the final selection at the MAC layer, multiple resources are randomly selected from a set of reported available resources. For SL-U, as described above, the resource pool may include more than one unlicensed / shared channel (i.e., multiple resource block sets / multiple RB sets) to support the transmission of large data packets that require multiple 20 MHz / RB sets. Based on the existing SL mode 2 resource sensing and exclusion process, the sensing operation is performed on all unlicensed / shared channels (RB sets) within the resource pool, and the exclusion and reporting of available resources can also be performed across multiple unlicensed channels / RB sets. However, if the existing random selection process for the final resource selection is still performed at the MAC layer, it may lead to one or more of the following results and have adverse consequences.

[0055] The selected resources may be scattered in different time slots (e.g., with a large transmission gap) and different unlicensed / shared channels (RB sets). When the selected transmission is performed in discontinuous time slots and / or with a large gap, the transmission may not be within the same COT duration. It is necessary to perform a separate type 1 LBT channel access process for each transmission, so the probability of LBT failure increases due to the long LBT sensing time. In addition, when an LBT failure occurs, the UE reselects another resource, but it cannot be guaranteed that the new LBT channel access process will definitely succeed, and the overall transmission delay is further increased.

[0056] Similarly, when the selected resources are scattered in different unlicensed channels / RB sets, two adverse results may occur. First, for large data packet transmission, non-continuous unlicensed channels / RB sets may be selected in the same time slot, resulting in the high PAPR problem that appears in the above RF transmission. Second, for small data packet transmission, even if resources of continuous unlicensed channels / RB sets are selected in the same time slot, the UE needs to perform two separate LBT channel access processes for each unlicensed channel / RB set respectively. As described above, the final transmission of one of the unlicensed channel / RB sets depends on the LBT success of all unlicensed channel / RB sets (i.e., either all succeed or all fail). In addition, even when the LBT channel access of all channels / RB sets is successful, a high PAPR problem may still occur when the selected resources are not adjacent to each other in the frequency domain.

[0057] In the worst case, the selected resources may be concentrated in an unlicensed / shared channel (RB set) that is more congested than other channels. In this case, since the unlicensed channel / RB set is continuously occupied by other transmissions (including transmissions of other RATs such as Wi-Fi, Bluetooth, LAA, etc.), the chance / possibility of successfully accessing the LBT channel is greatly reduced.

[0058] Another problem with using random resource selection in the final resource selection is resource fragmentation among multiple unlicensed / shared channels (RB sets) within the resource pool, resulting in a lack of continuous resource blocks in the frequency domain for large data packet transmissions.

[0059] Proposed resource selection methods and rules

[0060] To minimize the necessity for the SL Tx-UE to frequently perform long Class 1 LBT channel access procedures for its transmissions (thereby reducing the risk of LBT failure), avoid RF transmission problems in high PAPR / cubic metrics, and uneven wireless traffic loads among different unlicensed / shared channels (RB sets), and to provide more continuous resources in the frequency domain for large data packet transmissions, it is recommended to adopt one or more of the following resource selection methods.

[0061] Methods for solving / improving the problem of resource dispersion among multiple unlicensed channels / RB sets

[0062] Exemplary method 1

[0063] Select a continuous RB set for SL transmissions where the required resource size is greater than that of one unlicensed channel / RB set to reduce / avoid high PAPR problems in RF wireless transmissions and improve wireless resource utilization efficiency. Since there is no interference due to channel / spectrum leakage, GB PRBs can also be used.

[0064] When selecting resources for large data packet transmissions (e.g., when the number of resources required for each transmission is greater than that of one unlicensed channel / RB set), the Tx-UE can be made to select only resources from adjacent unlicensed channel / RB sets. This method has two important benefits. Generally, whenever there are gaps in the frequency resources used for wireless transmission in an OFDM symbol, depending on the size of the gap, this may cause spikes in the time domain, suddenly pushing the power amplifier in the transmission device to the saturation level, thereby causing a clipping effect on this peak value. This problem is well-known and can be measured by the PAPR level (or sometimes called the cubic metric) in the power amplifier. And whenever clipping occurs, a portion of the amplitude information in the quadrature amplitude modulation (QAM) modulated wireless signal is lost, resulting in some data that may not be correctly decoded.

[0065] Secondly, the GB PRB between two adjacent unauthorized / shared channels (RB sets) is now available, and the Tx-UE can also utilize this GB PRB to modulate and transmit its sidelink data. In wireless communication, the GB is typically located / assigned between two adjacent wireless channels / frequency bands to prevent / avoid interference caused by mutual leakage of wireless transmissions. Of course, the frequency resources within the GB cannot be used for any wireless transmission. On the other hand, when a device transmits on two wireless channels, since the wireless transmission covers two frequency portions / channels and there is no filtering of the signals between the two channels, there will be no mutual interference between the channels. Therefore, in SL-U, the Tx-UE that selects resources within two adjacent unauthorized / RB sets for transmission can utilize the GB PRB. Additionally, the Tx-UE can utilize the GB PRB, otherwise, due to the frequency gap between the GB PRBs, the above-mentioned high PAPR / cubic metric problem may again become a problem faced by the Tx-UE.

[0066] Figure 5 An exemplary illustration of one of the proposed resource selection methods for SL-U communication is shown. This method is based on selecting resources in adjacent channels / RB sets, so that the Tx-UE can utilize the additional resources in the GB PRB and can avoid the high PAPR problem caused by the frequency gap. In some embodiments, Figure 5 The illustration 100 shows a sidelink resource pool 101, whose frequency domain size covers three shared channels (i.e., RB set 1 102, RB set 2 103, and RB set 3 104) in the unauthorized spectrum band. As shown, the Tx-UE selects the resources of time slots 105, 106, 107, 108, and 109 for large data MAC PDU / TB transmission, and each resource covers two consecutive / adjacent unauthorized channels / RB sets. Since in each time slot, the selected resources cover two adjacent RB sets, the Tx-UE can also utilize the additional resources in the GB PRBs at 110, 111, and 112 for sidelink transmission.

[0067] Exemplary method 2

[0068] For the sidelink transmission of the same or different MAC PDU / TBs whose required resource size is less than one unauthorized channel / RB set, avoid selecting resources in different unauthorized channels / RB sets within the same time slot for simultaneous wireless transmission, due to the above-mentioned high PAPR / cubic metric problem and to avoid the problem of the UE performing a multi-channel access procedure (either all successful or all failed), which is more likely to result in an LBT failure and subsequent discarding of all MAC PDU / TBs.

[0069] In the case where the SL Tx-UE selects resources for small data packet transmission (e.g., when the number of resources required for each transmission is less than an unlicensed channel / RB set), regardless of whether the transmission is for the same or different MAC PDUs / TBs, resources from different unlicensed channel / RB sets in the same time slot can be avoided. That is, when the Tx-UE / MAC layer selects resources from a set of reported available resources for SL transmission of one or more MAC PDUs / TBs, at most one resource can be selected in a time slot (i.e., it is not allowed to select more than one resource), which includes any existing selected resources in the historical resource selection process. Generally speaking, when the selected resources are less than an unlicensed channel / RB set, at most one resource can be selected in a time slot for SL transmission. The reason for this rule / limitation is the same as that in Exemplary Method 1, where high PAPR / cubic metric problems may occur whenever there are transmission gaps in the frequency domain of the transmission carrier.

[0070] Another reason for avoiding selecting resources from different unlicensed channel / RB sets is the multi-channel access process of SL, where the Tx-UE needs to perform the LBT channel access process for each target unlicensed channel / RB set for transmission. If an LBT fails for any of the target unlicensed channel / RB sets (i.e., even if the LBT is successful for all other target unlicensed channel / RB sets), then none of the selected resources can be used (i.e., no MAC PDU / TB can be transmitted). If resources are selected from the same unlicensed channel / RB set, then only one LBT channel access process needs to be performed, and the probability of LBT success is higher.

[0071] Figure 6 Illustration 200 in [reference] shows an exemplary illustration of the above-proposed resource selection method for SL-U communication, which is based on selecting non-overlapping resources across different unlicensed channels / RB sets in the same time slot, thus avoiding high PAPR / cubic metric problems caused by large transmission gaps in the frequency domain. Figure 6The illustration 200 shows a sidelink resource pool 201, whose frequency-domain size covers three shared channels in the unlicensed spectrum band (i.e., RB set 1 202, RB set 2 203, RB set 3 204). As shown in the figure, the Tx-UE selects a set of resources 205 across multiple time slots (i.e., multiple channels / RB sets that are not in the same time slot) for transmitting a MAC PDU / TB to avoid high PAPR / cubic metric problems and avoid the need to perform a multi-channel access process based on the all-or-nothing channel access principle. When the Tx-UE selects another set of resources 206 for transmitting another MAC PDU / TB, the same selection method / rule is applied. Among them, this another set of resources 206 is selected from the same unlicensed channel / RB set 203 in multiple time slots. It should be understood that when selecting other resources for another MAC PDU / TB, the Tx-UE can consider the existing selected resources 205 in the resource pool 201 and avoid selecting resources 208 that overlap with any existing selection. Similarly, if the Tx-UE can select a new set of resources for the SL transmission of yet another new MAC PDU / TB, the new set of resources 207 cannot span multiple unlicensed channels / RB sets in the same time slot, and this selection can avoid resources 209 that overlap with any existing selection.

[0072] Method for solving / improving the resource dispersion problem with a large transmission gap between different time slots

[0073] Exemplary method 3

[0074] The TX-UE (e.g., for MCSt) can select a set of contiguous resources in time slots within the COT duration and within the same unlicensed channel / RB set to reduce / minimize the workload of the UE performing a long type 1 LBT channel access process and reduce the risk of LBT failure when obtaining access rights to the unlicensed / shared channel (RB set).

[0075] In the above exemplary method 1 and exemplary method 2, the resource selection principle in the frequency domain (i.e., across multiple unlicensed channels / RB sets) is designed to avoid certain undesirable RF transmission problems (i.e., high PAPR / cubic metric in the transmitted signal) in OFDM-based wireless communications, to make full use of other available idle resources of the GB PRB between the two unlicensed channels / RB sets, and to minimize the need for the Tx-UE to perform a multi-channel access process, thereby avoiding the situation where nothing can be transmitted when only one channel / RB set fails in the LBT channel access process.

[0076] The proposed exemplary method 3 aims to solve different problems when the selected resources are scattered in different time slots with large transmission gaps. As described above, the SL Tx-UE can perform the Class 1 LBT channel access procedure, enabling it to access the unlicensed / shared channel (RB set) and initiate a COT before using the selected resources for scheduled transmission. During the COT duration (the duration length depends on the priority level of the scheduled SL transmission), the Tx-UE has the right to continuously transmit / occupy the channel without performing another Class 1 LBT channel access procedure. If the transmission gap is greater than 16 μs or 25 μs, only a short Class 2A LBT channel access procedure or a short Class 2B LBT channel access procedure needs to be performed to ensure that the channel is still idle. Therefore, if the resources randomly selected by the Tx-UE are widely distributed in different time slots with large gaps, the Tx-UE may need to perform the Class 1 LBT channel access procedure for each randomly selected resource before the scheduled transmission. Thus, it is very costly for the Tx-UE and exposes it to a high LBT failure risk associated with Class 1 LBT.

[0077] In contrast, in exemplary method 3, the Tx-UE can select resources in consecutive time slots (e.g., the MCSt scheme) within the COT duration and within the same unlicensed channel / RB set. By performing the Class 1 LBT channel access procedure once to initiate the COT and performing MCSt during the COT duration, the workload of the UE can be minimized, and the risk of LBT failure can be reduced. If the COT duration is not sufficient to cover all the required transmissions (retransmissions) of the MAC PDU / TB, more MCSt resource sets can be selected for the remaining transmissions. Referring to Figure 6 Illustration 200 in, the Tx-UE selects three different resource sets 205, 206, 207 that are consecutive in time slots from three different unlicensed channels / RB sets 202, 203, 204 for the SL transmission of three different MAC PDUs / TBs. It should be noted that based on the resource selection proposed in exemplary method 2, these three resource sets (e.g., for MCSt) do not overlap in the time domain (thus avoiding the risk of multi-channel access). Since the Class 1 LBT channel access procedure can be performed at the beginning of each resource set to initiate a new COT, these three resource sets 205, 206, 207 do not need to be located within the same unlicensed channel / RB set.

[0078] Exemplary method 4

[0079] When the priority level of the sidelink transmission is equal to or higher than the COT initiated by the UE itself or the COT shared by another UE, the Tx-UE can preferentially consider or select resources for SL transmission within the COT initiated by the UE itself or the shared COT and in the same unlicensed channel / RB set as the COT initiated by the UE itself or the shared COT. This resource selection method can be used to minimize the workload of the UE to perform a new type 1 LBT channel access procedure for each SL transmission. The Tx-UE can perform this preferential consideration or selection of resources within the COT initiated by the UE itself or the COT shared by another UE during the resource primary selection or reselection (including replacement during the resource re-evaluation and preemption check procedures) of the MAC PDU / TB.

[0080] The Tx-UE can adopt another / different time-domain related resource selection rule / method to minimize the workload required for it to access the unlicensed channel / RB set and reduce the risk of LBT failure. This rule / method is to preferentially consider or select resources for SL transmission within the COT initiated by the UE itself or the COT shared by another UE and in the same unlicensed channel / RB set as the COT. When the Tx-UE obtains the COT sharing information from another UE, as long as the priority level of the SL transmission is equal to or higher than the shared COT, the Tx-UE can utilize the shared COT for SL transmission. Therefore, the Tx-UE can make full use of the COT initiated by the UE itself or the COT shared by another UE as part of the SL resource (re)selection and / or re-evaluation / preemption check procedures to improve the access success rate of the unlicensed channel / RB set and facilitate the execution of a long type 1 channel access procedure with uncertain results.

[0081] Method for solving the selection of resources from a congested unlicensed channel / RB set

[0082] Exemplary method 5

[0083] The UE performs CBR and / or CR measurements on each RB set and preferentially considers the RB set with a lower load / congestion level with a smaller measured CBR and / or CR value to perform resource selection.

[0084] In an SL resource pool that includes / covers more than one unlicensed channel / RB set, one unlicensed channel / RB set may be busier and more congested than other channel / RB sets. Generally, when an unlicensed channel / RB set is busy, the unlicensed channel / RB set becomes congested due to a large amount of user traffic transmitted by different UEs / devices in the channel. Therefore, when a Tx-UE needs to perform a Class 1 LBT channel access procedure, it is more difficult to access a busy / congested unlicensed channel / RB set than to access an unbusy unlicensed channel / RB set. Therefore, a new resource selection method is proposed, that is, the Tx-UE can perform CBR and / or CR measurements on the unlicensed channel / RB sets in the SL resource pool, and can select resources for SL transmission based on the measured CBR and / or CR values. For example, compared with other unlicensed channel / RB sets, the unlicensed channel / RB set with smaller measured CBR and / or CR values can be given priority for resource selection, so as to balance the uneven congestion load among different unlicensed channel / RB sets in the SL resource pool.

[0085] Exemplary method 6

[0086] Based on one or more historical LBT failure reports or consecutive LBT failure judgments / indications, (in the MAC layer) avoid selecting or (in the L1 process) the UE excludes the resources of the entire RB set.

[0087] Another mechanism for determining whether an unlicensed / shared channel (RB set) in a resource pool is busy or congested is based on the number of LBT failures reported to a higher layer (such as the MAC layer). In an SL-U system, LBT failures in the PHY layer are always reported to a higher layer for selecting replacement resources for packet retransmission. In the higher layer, whenever an LBT failure is reported, the value of a counter is incremented. When the counter reaches a certain value within a predefined time period, the higher layer determines consecutive LBT failures. Therefore, if the number of LBT failures sent / reported by the Tx-UE in a certain unlicensed channel / RB set is more than that in other channel / RB sets, or the number of LBT failures reported in this unlicensed channel / RB set exceeds a certain threshold (the threshold can be (pre)-configured or predefined), then this unlicensed channel / RB set is severely congested, and the Tx-UE can avoid selecting resources from this unlicensed channel / RB set. Or, if consecutive LBT failures are determined in an unlicensed channel / RB set, the MAC layer can avoid selecting resources from this unlicensed channel / RB set, and can also indicate to the L1 / PHY layer that there are consecutive LBT failures in the unlicensed channel / RB set, and L1 can exclude all resources of the indicated unlicensed channel / RB set from the candidate resource set (S A )

[0088] Methods for solving or improving the resource fragmentation problem of SL transmission across multiple unlicensed channels / RB sets

[0089] Exemplary method 7

[0090] Candidate resources of an edge unlicensed channel / RB set can be selected or preferentially selected for transmission within only a single unlicensed channel / RB set to avoid overloading / congestion of the central unlicensed channel / RB set, resulting in insufficient remaining resources for transmitting large-sized MAC PDUs / TBs that require multiple consecutive unlicensed channel / RB sets.

[0091] In SL-U communication, different UEs may need to transmit data packets of different sizes on multiple unlicensed channel / RB sets in an SL resource pool. In the above exemplary method 1, the Tx-UE can select resources from consecutive / adjacent unlicensed channel / RB sets for transmitting large data packets, thereby avoiding the high PAPR / cubic metric problems that often occur in OFDM signal transmission. On the other hand, for the case of transmitting small data packets (i.e., the number of required resources is less than that of an unlicensed channel / RB set), there is no restriction or regulation on which unlicensed channel / RB set can be selected. Therefore, by randomly selecting resources in the higher layer, the selected resources for transmitting small data packets will be distributed across all unlicensed channel / RB sets in the resource pool. When severe congestion occurs in the resource pool, it will be difficult for the Tx-UE to find one or the required number of resource sets located in consecutive / adjacent unlicensed channel / RB sets for transmitting large data packets. Therefore, it is beneficial to keep the central unlicensed channel / RB set in the resource pool idle and available so that large data packets can be transmitted on consecutive / adjacent unlicensed channel / RB sets. Therefore, it is proposed to preferentially consider or select resources in one or two edge unlicensed channel / RB sets in the SL resource pool for transmitting smaller MAC PDUs / TBs (i.e., the number of required resources is less than the total resources of each unlicensed channel / RB set). Resources of the edge unlicensed channel / RB set can be preferentially considered / selected based on at least one of the following.

[0092] Resources of the edge unlicensed channel / RB set cannot be used for SL transmission across multiple consecutive / adjacent unlicensed channel / RB sets. For example, when there are no available / candidate resources in adjacent unlicensed channel / RB sets, resources of this edge unlicensed channel / RB set can be selected or preferentially selected for transmitting smaller MAC PDUs / TBs.

[0093] The available resource ratio of the edge unlicensed channel / RB set is lower than the (pre)-configured or predefined threshold (e.g., 70%, 80%). The available resource ratio of the edge unlicensed channel / RB set is equal to or less than that of the central unlicensed channel / RB set. The available resource ratio (X%) of the edge unlicensed channel / RB set is greater than that (Y%) of the central unlicensed channel / RB set, and the difference between X and Y is less than or equal to the (pre)-configured or predefined value (Z). For example, X - Y ≤ 20%, where Z is 20%.

[0094] In summary, to minimize the necessity for the SL Tx-UE to frequently perform long Category 1 LBT channel access procedures for its transmissions (thereby reducing the risk of LBT failures), avoid RF transmission problems in high PAPR / cubic metrics, and uneven wireless traffic loads (including transmissions of other RATs such as NR-U, Wi-Fi, etc.) between different unlicensed / shared channels (RB sets), and provide more frequency-domain continuous resources for large packet transmissions, it is recommended to adopt one or more of the following resource selection methods. The above exemplary Method 1 and exemplary Method 2 describe methods for solving / improving the resource fragmentation problem between multiple unlicensed channels / RB sets. The above exemplary Method 3 and exemplary Method 4 describe methods for solving / improving the resource fragmentation problem with large transmission gaps between different time slots. The above exemplary Method 5 and exemplary Method 6 describe methods for solving the problem of selecting resources from congested unlicensed channels / RB sets. The above exemplary Method 7 describes methods for solving or improving the resource fragmentation problem of SL transmissions across multiple unlicensed channels / RB sets.

[0095] Figure 7Illustrated is a UE 900 for wireless communication according to an embodiment of the present disclosure. The UE 900 includes an actuator 901, which is configured to perform resource selection based on at least one of the following: select consecutive resources in an RB set for sidelink transmission; avoid selecting resources in different RB sets in the same time slot for simultaneous transmission; within the COT duration and within the same RB set, select resources in consecutive time slots; when the priority level of the sidelink transmission is equal to or higher than the self-initiated COT or the COT shared by other UEs, within the self-initiated COT or the shared COT and in the same RB set as the self-initiated COT or the shared COT, prioritize or select resources for sidelink transmission; perform CBR and / or CR measurements on each RB set, and based on the CBR and / or CR measurements, prioritize or select the RB set with a lower load / congestion level with a smaller measured CBR and / or CR value; based on one or more historical LBT failure reports or consecutive LBT failure judgments / indications, avoid selecting or excluding resources of an entire RB set; and prioritize or select resources in one or two edge RB sets in a resource pool. This can solve the problems of the prior art, improve the success rate of accessing the unlicensed / shared channel to send sidelink data information, avoid uneven wireless traffic load between different unlicensed / shared channels, reduce the wireless transmission PAPR problem, improve the utilization rate of wireless resources, avoid frequency resource fragmentation, provide good communication performance, and / or provide high reliability.

[0096] In some embodiments, the actuator 901 is configured to select resources in consecutive RB sets for sidelink transmission of one or more resources that need to span more than one RB set, and / or the actuator 901 is configured to utilize resources in the GB PRBs between the consecutive RB sets. In some embodiments, the actuator 901 is configured to avoid selecting resources in different RB sets in the same time slot for sidelink transmission of the same or different MAC PDUs or TBs with a required resource size smaller than one RB set. In some embodiments, the actuator 901 is configured to prioritize or select resources for sidelink transmission within the self-initiated COT or the shared COT during the resource primary selection or reselection process of the MAC PDU or TB. In some embodiments, the actuator 901 is configured to prioritize or select resources in one or two edge RB sets in a resource pool for transmission within a single RB set.

[0097] In some embodiments, the actuator 901 is configured to, when there are no available / candidate resources in adjacent RB sets, preferentially consider or select resources in one or two edge RB sets in the resource pool for transmission within a single RB set. In some embodiments, when preferentially considering or selecting resources in one or two edge RB sets in the resource pool, the available / candidate resource ratio of one or two edge RB sets in the resource pool is lower than a configured or predefined threshold. In some embodiments, the configured or predefined threshold is 70% or 80% of the available / candidate resources of one or two edge RB sets in the resource pool. In some embodiments, when the actuator 901 preferentially considers or selects resources in one or two edge RB sets in the resource pool, the available / candidate resource ratio of one or two edge RB sets in the resource pool is equal to or less than the available / candidate resource ratio of one or more central RB sets.

[0098] In some embodiments, the actuator 901 is configured to, when preferentially considering or selecting resources in one or two edge RB sets in the resource pool, the available / candidate resource ratio of one or two edge RB sets in the resource pool is greater than the available / candidate resource ratio of one or more central RB sets. In some embodiments, X% represents the available / candidate resource ratio of the edge RB set, Y% represents the available / candidate resource ratio of the central RB set, and the difference between X% and Y% is less than or equal to a configured or predefined value. In some embodiments, the configured or predefined value is equal to 20%.

[0099] The commercial benefits of some embodiments are as follows. 1. Solve the problems in the prior art. 2. Achieve a higher success rate when accessing unlicensed / shared channels for transmitting sidelink data information. 3. Avoid uneven wireless traffic loads between different unlicensed / shared channels. 4. Provide fewer problems with the peak-to-average power ratio (PAPR) of wireless transmissions. 5. Utilize more wireless resources. 6. Avoid frequency resource fragmentation. 7. Provide good communication performance. 8. Provide high reliability. 9. Provide good communication performance. 10. Provide high reliability. 11. Some embodiments of the present disclosure are by 5G-NR chipset suppliers, V2X communication system development suppliers, including automotive manufacturers such as cars, trains, trucks, buses, bicycles, motorcycles, helmets, drones (unmanned aerial vehicles), smartphone manufacturers, smartwatches, wireless earbuds, wireless headphones, communication devices for public safety, remote control vehicles, and robots, AR / VR device manufacturers (for example, for games, conferences / seminars, education), smart home appliances (including TVs, stereos, speakers, lights, doorbells, locks, cameras, conference headsets, etc.), smart factory and warehouse equipment (including IIoT devices, robots, robotic arms, and between simple production machines). In some embodiments, the commercial benefits and commercial importance of the disclosed invention include reducing the power consumption of wireless communication, which means longer device runtime and / or longer runtime between battery charges, thus bringing a better user experience and product satisfaction. Some embodiments of the present disclosure are combinations of "technologies / processes" that can be adopted in 3GPP specifications to create end products. Some embodiments of the present disclosure relate to mobile cellular communication technologies for providing direct device-to-device (D2D) wireless communication services in 3GPP NR Release 17 and later versions.

[0100] Figure 8 FIG. is a block diagram of an example system 700 for wireless communication according to an embodiment of the present disclosure. The embodiments described herein can be implemented into the system using any appropriately configured hardware and / or software. Figure 8 System 700 is shown, and system 700 includes at least a radio frequency (RF) circuit 710, a baseband circuit 720, an application circuit 730, a memory / memory 740, a display 750, a camera 760, sensors 770, and an input / output (I / O) interface 780 that are coupled to each other as shown.

[0101] The application circuit 730 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors). The processors may be coupled to memory / memories and configured to execute instructions stored in the memory / memories to enable various applications and / or operating systems to run on the system.

[0102] The baseband circuit 720 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors may include baseband processors. The baseband circuit may process various wireless control functions that enable communication with one or more wireless networks via the RF circuit. The wireless control functions may include, but are not limited to, signal modulation, encoding, decoding, wireless frequency shift, etc. In some embodiments, the baseband circuit may provide communication compatible with one or more wireless technologies. For example, in some embodiments, the baseband circuit may support communication with an evolved universal terrestrial radio access network (EUTRAN) and / or other wireless metropolitan area network (WMAN), wireless local area network (WLAN), wireless personal area network (WPAN). Embodiments in which the baseband circuit is used to support wireless communication for more than one wireless protocol may be referred to as multi-mode baseband circuits.

[0103] In various embodiments, the baseband circuit 720 may include circuitry that operates on signals that are not strictly considered to be at baseband frequencies. For example, in some embodiments, the baseband circuit may include circuitry that operates on signals having an intermediate frequency that is between the baseband frequency and the radio frequency.

[0104] The RF circuit 710 may communicate with a wireless network by using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuit may include switches, filters, amplifiers, etc. to facilitate communication with the wireless network.

[0105] In various embodiments, the RF circuit 710 may include circuitry that operates on signals that are not strictly considered to be at radio frequencies. For example, in some embodiments, the RF circuit may include circuitry that operates on signals having an intermediate frequency that is between the baseband frequency and the radio frequency.

[0106] In various embodiments, the transmitter circuitry, control circuitry, or receiver circuitry discussed above with respect to the user equipment, eNB, or gNB may be embodied, in whole or in part, in one or more of a radio frequency circuitry, a baseband circuitry, and / or an application circuitry. As used herein, "circuitry" may refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and / or memory (shared, dedicated, or group) that executes one or more software or firmware programs, combinational logic circuitry, and / or other suitable hardware components that provide the described functionality. In some embodiments, the 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.

[0107] In some embodiments, some or all of the constituent components of the baseband circuitry, application circuitry, or memory / memories may be implemented together on a system on a chip (SOC).

[0108] Memory / memory 740 may be used to load and store data and / or instructions, e.g., for the system. The memory / memory of one embodiment may include any combination of suitable volatile memory (e.g., dynamic random access memory (DRAM)) and / or non-volatile memory (e.g., flash memory).

[0109] In various embodiments, the I / O interface 780 may include one or more user interfaces designed to allow a user to interact with the system and / or a peripheral component interface designed to allow peripheral components to interact with 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.

[0110] In various embodiments, the sensor 770 may include one or more sensing 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 the baseband circuitry and / or RF circuitry or interact with the baseband circuitry or RF circuitry to communicate with components of a positioning network such as global positioning system (GPS) satellites.

[0111] In various embodiments, the display 750 may include displays such as liquid crystal displays and touch screen displays. 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 or a different architecture. In appropriate cases, 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.

[0112] Those of ordinary skill in the art will understand that the units, algorithms, and steps described and disclosed in the embodiments of the present disclosure may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented on hardware or software depends on the application conditions and design requirements of the technical solution.

[0113] Those of ordinary skill in the art may use different methods to implement the functions for each specific application, and such implementation shall not exceed the scope of the present disclosure. Those of ordinary skill in the art will understand that since the working processes of the above-mentioned systems, devices, and units are basically the same, those of ordinary skill in the art may refer to the working processes of the systems, devices, and units in the above-mentioned embodiments. For the sake of description and simplicity, these working processes will not be elaborated herein.

[0114] It can be understood that the systems, devices, and methods disclosed in the embodiments of the present disclosure may be implemented in other ways. The above embodiments are merely exemplary. The division of units is only based on logical functions, and there are other divisions in implementation. Multiple units or components may be combined or integrated into another system. It is also possible to omit or skip certain features. On the other hand, the mutually coupled, directly coupled, or communicatively coupled shown or discussed runs indirectly or communicatively through some ports, devices, or units in electrical, mechanical, or various other forms. The units shown as separate components for explanation are physically separated or not separated. The units shown may be physical units or not physical units, that is, located in one place or distributed on multiple network units. Some or all units are used according to the purposes of the embodiments. In addition, the functional units in each embodiment may be integrated into one processing unit, physically independent, or integrated into one processing unit with two or more units.

[0115] When the software functional unit is used and sold as a product implementation, it can be stored in a readable storage medium in a computer. Based on this understanding, the technical solution proposed in this disclosure can be essentially or partially implemented in the form of a software product. Alternatively, a part of the technical solution that is beneficial to the prior art can be implemented in the form of a software product. The software product in the computer is stored in the storage medium and includes a plurality of commands for a computing device (such as a personal computer, a server, or a network device) to execute all or part of the steps disclosed in the embodiments of this disclosure. The storage medium includes a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a floppy disk, or other various media capable of storing program codes.

[0116] Although this disclosure has been described in connection with the embodiments that are considered to be the most practical and preferred, it should be understood that this disclosure is not limited to the disclosed embodiments, 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 for sidelink communication performed by a user equipment (UE), comprising: The UE performs resource selection based on at least one of the following: Select resources in a continuous resource block (RB) set for sidelink transmission; Avoid selecting resources in different RB sets in the same time slot for simultaneous transmission; Select resources in continuous time slots within the duration of a channel occupancy time (COT) and within the same RB set; When the priority level of the sidelink transmission is equal to or higher than the self-initiated COT of the UE or the COT shared by other UEs, prioritize or select resources for sidelink transmission within the self-initiated COT or the shared COT and in the same RB set as the self-initiated COT or the shared COT; Perform channel busy rate (CBR) and / or channel occupancy rate (CR) measurements for each RB set, and based on the CBR and / or CR measurements, prioritize or select the RB set with a lower load / congestion level having a smaller measured CBR and / or CR value; Based on one or more historical listen-before-talk (LBT) failure reports or consecutive LBT failure judgments / indications, avoid selecting or excluding resources of an entire RB set; and Prioritize or select resources in one or two edge RB sets in a resource pool.

2. The method according to claim 1, wherein, Select the resources in the continuous RB set for sidelink transmission of one or more resources that need to span more than one RB set, and / or the UE uses the resources in the physical resource blocks (PRBs) of the guard band (GB) between the continuous RB sets.

3. The method according to claim 1 or 2, wherein, Avoid selecting the resources in the different RB sets in the same time slot for sidelink transmission of the same or different media access control (MAC) protocol data units (PDUs) or transport blocks (TBs) with a required resource size smaller than one RB set.

4. The method according to any one of claims 1 to 3, wherein, During the initial resource selection or reselection process of a MAC PDU or TB, prioritize or select the resources for sidelink transmission within the self-initiated COT or the shared COT.

5. The method according to any one of claims 1 to 4, wherein, Prioritize or select the resources in one or two edge RB sets in the resource pool for transmission within a single RB set.

6. The method according to any one of claims 1 to 5, wherein, When there are no available / candidate resources in adjacent RB sets, prioritize or select the resources in one or two edge RB sets in the resource pool for transmission within a single RB set.

7. The method according to any one of claims 1 to 6, wherein, When prioritizing or selecting the resources in one or two edge RB sets in the resource pool, the proportion of available / candidate resources in one or two edge RB sets in the resource pool is lower than a configured or predefined threshold.

8. The method according to claim 7, wherein, The configured or predefined threshold is 70% or 80% of the available / candidate resources of the one or two edge RB sets in the resource pool.

9. The method according to any one of claims 1 to 8, wherein, when prioritizing or selecting the resources in the one or two edge RB sets in the resource pool, the available / candidate resource ratio of the one or two edge RB sets in the resource pool is equal to or less than the available / candidate resource ratio of one or more central RB sets.

10. The method according to any one of claims 1 to 9, wherein, when prioritizing or selecting the resources in the one or two edge RB sets in the resource pool, the available / candidate resource ratio of the one or two edge RB sets in the resource pool is greater than the available / candidate resource ratio of one or more central RB sets.

11. The method according to claim 10, wherein, X% represents the available / candidate resource ratio of the edge RB set, Y% represents the available / candidate resource ratio of the central RB set, and the difference between X% and Y% is less than or equal to a configured or predefined value.

12. The method according to claim 11, wherein, the configured or predefined value is equal to 20%.

13. A user equipment (UE), comprising: an actuator for performing resource selection based on at least one of the following: selecting resources in a continuous resource block (RB) set for sidelink transmission; avoiding selecting resources in different RB sets in the same time slot for simultaneous transmission; selecting resources in continuous time slots within a channel occupancy time (COT) duration and within the same RB set; when the priority level of the sidelink transmission is equal to or higher than the self-initiated COT or the COT shared by other UEs, prioritizing or selecting resources for sidelink transmission within the self-initiated COT or the shared COT and within the same RB set as the self-initiated COT or the shared COT; measuring the channel busy rate (CBR) and / or channel occupancy rate (CR) for each RB set, and based on the CBR and / or CR measurements, prioritizing or selecting the RB set with a lower load / congestion level having a smaller measured CBR and / or CR value; and avoiding selecting or excluding resources of an entire RB set based on one or more historical listen-before-talk (LBT) failure reports or continuous LBT failure judgments / indications; and prioritizing or selecting resources in one or two edge RB sets in the resource pool.

14. A user equipment (UE), comprising: a memory; a transceiver; and a processor coupled to the memory and the transceiver, wherein the UE is configured to perform the method according to any one of claims 1 to 12.

15. A non-transitory machine-readable storage medium having instructions stored thereon, which when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 12.

16. A chip, comprising: A processor for invoking and running a computer program stored in a memory, so that a device installed with the chip executes the method according to any one of claims 1 to 12.

17. A computer-readable storage medium storing a computer program, wherein, the computer program causes a computer to execute the method according to any one of claims 1 to 12.

18. A computer program product comprising a computer program, wherein, the computer program causes a computer to execute the method according to any one of claims 1 to 12.

19. A computer program, wherein, the computer program causes a computer to execute the method according to any one of claims 1 to 12.

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