Method and apparatus for determining resources for sidelink transmission

Abstract

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments disclosed herein provide a method performed by a first node in a communication system comprising transmitting N physical sidelink shared channels (PSSCHs); determining M resources for receiving Hybrid Automatic Retransmission Request Acknowledgement (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N; receiving the HARQ-ACK feedback information on the determined M resources; and determining whether the transmitted N PSSCHs are successfully received based on the received HARQ-ACK feedback information.

Description

METHOD AND APPARATUS FOR DETERMINING RESOURCES FOR SIDELINK TRANSMISSION

[0001] The present disclosure relates to the field of wireless communication technology and in particular to a method for Sidelink (SL) communication based positioning and a device thereof in a wireless system in the fifth generation new radio access technology (5G NR) system.

[0002] 5G mobile communication technologies define broad frequency bands such that high transmission rates and new services are possible, and can be implemented not only in "Sub 6GHz" bands such as 3.5GHz, but also in "Above 6GHz" bands referred to as mmWave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technologies (referred to as Beyond 5G systems) in terahertz bands (for example, 95GHz to 3THz bands) in order to accomplish transmission rates fifty times faster than 5G mobile communication technologies and ultra-low latencies one-tenth of 5G mobile communication technologies.

[0003] At the beginning of the development of 5G mobile communication technologies, in order to support services and to satisfy performance requirements in connection with enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine-Type Communications (mMTC), there has been ongoing standardization regarding beamforming and massive MIMO for mitigating radio-wave path loss and increasing radio-wave transmission distances in mmWave, supporting numerologies (for example, operating multiple subcarrier spacings) for efficiently utilizing mmWave resources and dynamic operation of slot formats, initial access technologies for supporting multi-beam transmission and broadbands, definition and operation of BWP (BandWidth Part), new channel coding methods such as a LDPC (Low Density Parity Check) code for large amount of data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network specialized to a specific service.

[0004] Currently, there are ongoing discussions regarding improvement and performance enhancement of initial 5G mobile communication technologies in view of services to be supported by 5G mobile communication technologies, and there has been physical layer standardization regarding technologies such as V2X (Vehicle-to-everything) for aiding driving determination by autonomous vehicles based on information regarding positions and states of vehicles transmitted by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) aimed at system operations conforming to various regulation-related requirements in unlicensed bands, NR UE Power Saving, Non-Terrestrial Network (NTN) which is UE-satellite direct communication for providing coverage in an area in which communication with terrestrial networks is unavailable, and positioning.

[0005] Moreover, there has been ongoing standardization in air interface architecture / protocol regarding technologies such as Industrial Internet of Things (IIoT) for supporting new services through interworking and convergence with other industries, IAB (Integrated Access and Backhaul) for providing a node for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying random access procedures (2-step RACH for NR). There also has been ongoing standardization in system architecture / service regarding a 5G baseline architecture (for example, service based architecture or service based interface) for combining Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) for receiving services based on UE positions.

[0006] As 5G mobile communication systems are commercialized, connected devices that have been exponentially increasing will be connected to communication networks, and it is accordingly expected that enhanced functions and performances of 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research is scheduled in connection with eXtended Reality (XR) for efficiently supporting AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality) and the like, 5G performance improvement and complexity reduction by utilizing Artificial Intelligence (AI) and Machine Learning (ML), AI service support, metaverse service support, and drone communication.

[0007] Furthermore, such development of 5G mobile communication systems will serve as a basis for developing not only new waveforms for providing coverage in terahertz bands of 6G mobile communication technologies, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), array antennas and large-scale antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum), and RIS (Reconfigurable Intelligent Surface), but also full-duplex technology for increasing frequency efficiency of 6G mobile communication technologies and improving system networks, AI-based communication technology for implementing system optimization by utilizing satellites and AI (Artificial Intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at levels of complexity exceeding the limit of UE operation capability by utilizing ultra-high-performance communication and computing resources.

[0008] 5th generation (5G) or new radio (NR) mobile communications is recently gathering increased momentum with all the worldwide technical activities on the various candidate technologies from industry and academia. The candidate enablers for the 5G / NR mobile communications include massive antenna technologies, from legacy cellular frequency bands up to high frequencies, to provide beamforming gain and support increased capacity, new waveform (e.g., a new radio access technology (RAT)) to flexibly accommodate various services / applications with different requirements, new multiple access schemes to support massive connections, and so on.

[0009] In the Long Term Evolution (LTE) technology, sidelink communication includes two main mechanisms, which are Device to Device (D2D) direct communication and Vehicle to everything (Vehicle to Vehicle / Infrastructure / Pedestrian / Network, V2X), among which V2X is designed on the basis of D2D technology and is superior to D2D in terms of data rate, delay, reliability and link capacity, and is the most representative sidelink communication technology in LTE technology.

[0010] As the evolution technology of LTE, the 5G NR system also includes the further evolution of sidelink communication. As the evolution version of LTE V2X technology, NR V2X technology is formulated in Release 16, and its performance in all aspects is superior. In Release 17, the 5G NR system is expected to further extend the application scenarios of NR V2X to other wider application scenarios, such as commercial sidelink communication and Public Safety (PS) scenarios. In Release 18, 5G NR SL will further introduce the evolution corresponding to other scenarios and applications, such as SL technology in high frequency (FR2), unlicensed frequency band, and SL technology corresponding to specific applications such as positioning.

[0011] In line with development of the communication systems, there is a need for method for sidelink UE to select resources for transmitting and receiving feedback signal.

[0012] The technical subjects pursued in the disclosure may not be limited to the above mentioned technical subjects, and other technical subjects which are not mentioned may be clearly understood, through the following descriptions, by those skilled in the art to which the disclosure pertains.

[0013] The disclosure provides a method performed by a first node in a communication system and a node device for performing the method, the method comprises: transmitting N physical sidelink shared channels (PSSCHs); determining M resources for receiving Hybrid Automatic Retransmission Request Acknowledgment (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N; receiving the HARQ-ACK feedback information on the determined M resources; and determining whether the transmitted N PSSCHs are successfully received based on the received HARQ-ACK feedback information.

[0014] In the sidelink communication system of LTE and NR, the sidelink communication system is designed mainly based on the requirements of specific D2D and vehicle business scenarios, and the frequency bands used by the system are mainly concentrated on specific licensed frequency bands, such as ITS frequency bands dedicated for vehicle traffic. With the development of 5G technology, the business modes for sidelink communication are growing, so it is necessary to enhance the sidelink communication technology so that it can be applied to a wider range of application scenarios, such as XR, IIoT, RedCap and so on. For the business requirements of some future application scenarios, the transmission rate, latency and reliability achieved by the current sidelink communication technology are needed to be further enhanced. A feasible method is to apply the sidelink communication to more frequency bands, such as unlicensed frequency bands, to increase the transmission rate and improve reliability supported by the sidelink system by increasing bandwidth, and reduce the service transmission latency through high-frequency communication. However, the current sidelink communication system has not discussed the possibility of sidelink communication in the unlicensed frequency bands, and has not introduced any enhancement mechanism for the unlicensed frequency bands.

[0015] In the sidelink communication system used for data transmission, the feedback resources of the sidelink data channel are determined through a fixed mapping, which may result in the UE not being able to flexibly indicate HARQ-ACK feedback, and may result in the UE needing to transmit more signals simultaneously than the limit of the UE capacity.

[0016] The present disclosure provides a method for sidelink UE to select resources for transmitting and receiving feedback signal. Through the method, UE can determine feedback resources more flexibly and further select resources that are more suitable for transmitting and receiving HARQ-ACKs among possible feedback resources.

[0017] According to some embodiments of the present disclosure, a method performed by a first node in a communication system is provided, comprising: transmitting N physical sidelink shared channels (PSSCHs); determining M resources for receiving Hybrid Automatic Retransmission Request Acknowledgment (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N; receiving the HARQ-ACK feedback information on the determined M resources; and determining whether the transmitted N PSSCHs are successfully received based on the received HARQ-ACK feedback information.

[0018] In some embodiments, N PSSCHs are transmitted on multiple consecutive time units; and / or at least one of N PSSCHs has HARQ-ACK feedback enabled.

[0019] In some embodiments, determining M resources for receiving HARQ-ACK feedback information, includes one of: determining that M physical sidelink feedback channel (PSFCH) resources among the N PSFCH resources corresponding to the N PSSCHs are resources for receiving HARQ-ACK feedback information; determining M resources for receiving HARQ-ACK feedback information by using a sensing based and / or random selection based resource determination method; determining M resources for receiving HARQ-ACK feedback information based on a second indication received for resource for HARQ-ACK feedback information, wherein the M resources determined based on sensing and / or random selection, and the M resources determined based on the second indication, include at least one of physical sidelink control channel (PSCCH) resources, PSSCH resources, and PSFCH resources.

[0020] In some embodiments, the M PSFCH resources at least include one of: no more than M PSFCH resources corresponding to the earliest PSSCH among the N PSSCHs; no more than M PSFCH resources corresponding to the latest PSSCH among the N PSSCHs; no more than M PSFCH resources with the highest frequency domain index among the N PSFCH resources; no more than M PSFCH resources with the lowest frequency domain index among the N PSFCH resources; no more than M PSFCH resources randomly selected from the N PSFCH resources.

[0021] In some embodiments, N PSSCHs correspond to one HARQ process and / or one transmission block (TB), or the N PSSCHs correspond to multiple HARQ processes and / or multiple TBs, and M is equal to 1.

[0022] In some embodiments, the M PSFCH resources further include: no more than M PSFCH resources corresponding to the PSSCH with the highest priority among the N PSSCHs.

[0023] In some embodiments, N PSSCHs correspond to multiple HARQ processes and / or multiple TBs, and M is greater than or equal to 1.

[0024] In some embodiments, determining that M PSFCH resources among the N PSFCH resources corresponding to the N PSSCHs are resources for receiving HARQ-ACK feedback information includes: when n PSFCH resources among N PSFCH resources corresponding to the N PSSCH resources are on a same time unit, determining n1 resources among n PSFCH resources are the resources for receiving HARQ-ACK feedback information, where n is a positive integer and n1 is a positive integer not greater than n.

[0025] In some embodiments, the method also includes transmitting a first indication of resources for HARQ-ACK feedback information to a second node.

[0026] In some embodiments, the first indication is included in a sidelink control information (SCI).

[0027] In some embodiments, the HARQ-ACK feedback information corresponding to the resources for HARQ-ACK feedback information includes at least one of: HARQ-ACK feedback information corresponding to at least one of the N PSSCHs; when resources are indicated in the SCI, the HARQ-ACK feedback information corresponding to the PSSCH associated with the SCI; when resources are indicated in the SCI, the HARQ-ACK feedback information corresponding to at least one among the N PSSCHs not later than the PSSCHs associated with the SCI.

[0028] In some embodiments, receiving the HARQ-ACK feedback information on the determined M resources includes: when the determined M resources are M PSFCH resources, receiving bundled PSFCHs on m PSFCH resources amongthe determined M PSFCH resources, where m is a positive integer not greater than M.

[0029] In some embodiments, determining whether the transmitted N PSSCHs are successfully received based on the received HARQ-ACK feedback information includes: if the received HARQ-ACK feedback information corresponding to the transmitted N PSSCHs includes at least one ACK, determining that the transmitted N PSSCHs are successfully received,; otherwise, determining that the N transmitted PSSCHs are not successfully received.

[0030] In some embodiments, the method further includes: among the transmitted N PSSCHs, for the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received, determining that the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received is successfully received when the first condition set is met, wherein, the first condition set includes: the N PSFCH resources corresponding to the transmitted N PSSCHs are on the same time unit; at least one ACK is received on the N PSFCH resources corresponding to the transmitted N PSSCHs.

[0031] In some embodiments, the first condition set further includes: among the transmitted N PSSCHs, the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received uses a NACK-only groupcast feedback option.

[0032] In some embodiments, the method further includes: among the transmitted N PSSCHs, for the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received, determining that the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received is not successfully received when a second condition set is met, wherein, the second condition set includes: the N PSFCH resources corresponding to the transmitted N PSSCHs are on the same time unit.

[0033] In some embodiments, the second condition set further includes: among the transmitted N PSSCHs, the PSSCH corresponding to the PSFCH resources on which no ACK or NACK is received uses groupcast feedback option or unicast feedback option for ACK and NACK.

[0034] In some embodiments, the first condition set or second condition set further includes receiving at least one NACK on N PSFCH resources corresponding to the transmitted N PSSCHs.

[0035] According to some embodiments of the present disclosure, a method performed by a second node in the communication system is provided, comprising: receiving the N physical sidelink shared channels (PSSCHs); determining M resources for transmitting Hybrid Automatic Retransmission Request Acknowledgement (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N; and transmitting the HARQ-ACK feedback information on the determined M resources.

[0036] In some embodiments, N PSSCHs are received on multiple consecutive time units; and / or at least one of N PSSCHs has HARQ-ACK feedback enabled.

[0037] In some embodiments, determining M resources for transmitting HARQ-ACK feedback information includes one of: determining that M physical sidelink feedback channel (PSFCH) resources among the N PSFCH resources corresponding to the N PSSCHs are resources for transmitting HARQ-ACK feedback information; determining M resources for transmitting HARQ-ACK feedback information by using a sensing based and / or random selection based resource determination method; determining M resources for transmitting HARQ-ACK feedback information based on a first indication received for resource for HARQ-ACK feedback information, wherein the M resources determined based on sensing and / or random selection and the M resources determined based on the first indication, include at least one of physical sidelink control channel (PSCCH) resources, PSSCH resources, and PSFCH resources.

[0038] In some embodiments, the M PSFCH resources at least include one of: no more than M PSFCH resources corresponding to the earliest PSSCH among the N PSSCHs; no more than M PSFCH resources corresponding to the latest PSSCH among the N PSSCHs; no more than M PSFCH resources with the highest frequency domain index among the N PSFCH resources; no more than M PSFCH resources with the lowest frequency domain index among the N PSFCH resources; no more than M PSFCH resources randomly selected from the N PSFCH resources.

[0039] In some embodiments, N PSSCHs correspond to one HARQ process and / or one transmission block (TB), or the N PSSCHs correspond to multiple HARQ processes and / or multiple TBs, and M is equal to 1.

[0040] In some embodiments, the M PSFCH resources further include: no more than M PSFCH resources corresponding to the PSSCH with the highest priority among the N PSSCHs.

[0041] In some embodiments, N PSSCHs correspond to multiple HARQ processes and / or multiple TBs, and M is greater than or equal to 1.

[0042] In some embodiments, determining M PSFCH resources among the N PSFCH resources corresponding to N PSSCH resources are the resources for transmitting HARQ-ACK feedback information includes: when n PSFCH resources among the N PSFCH resources corresponding to N PSSCH resources are on the same time unit and the number of PSFCHs needed to be transmitted on the time unit exceeds a capacity of the second node, determining that n1 PSFCH resources among the n PSFCH resources are the resources used to transmit HARQ-ACK feedback information, where n is a positive integer and n1 is a positive integer and not greater than n and n1 is number such that the number of PSFCHs needed to be transmitted on the time unit does not exceed the capacity of the second node.

[0043] In some embodiments, the method also includes transmitting a second indication of resources for HARQ-ACK feedback information to the first node.

[0044] In some embodiments, the second indication is included in a sidelink control information (SCI).

[0045] In some embodiments, the HARQ-ACK feedback information corresponding to the resources for HARQ-ACK feedback information includes at least one of: HARQ-ACK feedback information corresponding to at least one of the N PSSCHs; when resources are indicated in the SCI, the HARQ-ACK feedback information corresponding to the PSSCH associated with the SCI; when resources are indicated in the SCI, the HARQ-ACK feedback information corresponding to at least one among the N PSSCHs not later than the PSSCHs associated with the SCI.

[0046] In some embodiments, transmitting the HARQ-ACK feedback information on the determined M resources includes: when the determined M resources are M PSFCH resources, transmitting bundled PSFCHs on m PSFCH resources amongthe determined M PSFCH resources, where m is a positive integer not greater than M.

[0047] In some embodiments, if multiple HARQ-ACK feedback information corresponding to the M PSFCH resources includes at least one ACK, the HARQ-ACK feedback information transmitted on the bundled PSFCHs is ACK; if multiple HARQ-ACK feedback information corresponding to the M PSFCH resources includes at least one NACK, the HARQ-ACK feedback information transmitted on the bundled PSFCHs is NACK.

[0048] In some embodiments, transmitting the HARQ-ACK feedback information on the determined M resources further includes, when the determined M resources include PSFCH resources, performing at least one of: iif the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple ACKs, prioritizing transmitting ACKs on k1 PSFCH resource among k PSFCH resources corresponding to the multiple ACKs, and / or not transmitting PSFCHs on other k-k1 PSFCH resources among the k PSFCH resources corresponding to the multiple ACKs, where k is a positive integer and k1 is a positive integer not greater than k; if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple NACKs, prioritizing transmitting NACKs on p1 PSFCH resources among p PSFCH resources corresponding to the multiple NACKs, and / or not transmitting PSFCHs on other p-p1 PSFCH resources among the p PSFCH resources corresponding to the multiple NACKs, where p is a positive integer and p1 is a positive integer not greater than p; if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple NACKs and the multiple NACKs include the NACKs corresponding to the PSSCH resources with NACK-only feedback option enabled, prioritizing transmitting NACKs on q1 PSFCH resources corresponding to the NACKs corresponding to the PSSCH with NACK-only groupcast feedback option enabled, and / or not transmitting PSFCHs on other q-q1 PSFCH resources among q PSFCH resources corresponding to the multiple NACKs, where q is a positive integer and q1 is a positive integer not greater than q; if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple NACKs and the multiple NACKs include the NACKs corresponding to the PSSCH resources with NACK-only feedback option enabled, prioritizing transmitting NACKs on q1 PSFCH resources corresponding to the NACKs corresponding the PSSCH with NACK-only groupcast feedback option enabled, and prioritizing transmitting NACKs on q2 PSFCH resources among the PSFCH resources corresponding to the remaining NACKs, and / or not transmitting PSFCH on other q-q1-q2 PSFCH resources among q PSFCH resources corresponding to the multiple NACKs, where q is a positive integer and q1, q2 are positive integers not greater than q.

[0049] In some embodiments, the method further includes, when the determined M resources include PSFCH resources, using at least one of:

[0050] the transmission of PSFCH with higher priority is prioritized over the transmission of PSFCH with lower priority, and / or, for the transmissions of PSFCH with same priorities, the transmission of PSFCH not based on multi-consecutive slots transmission (MCSt) is prioritized over the transmission of MCSt-based PSFCH; not transmitting at least one MCSt-based PSFCH, and when prioritization is still required for the remaining PSFCHs, the transmission of PSFCH with higher priority is prioritized over the transmission of PSFCH with lower priority; based on the adjusted priority, not transmitting PSFCH with lower priority, wherein the adjusted priority includes the adjusted priority of PSFCH based on whether the PSFCH is MCSt-based.

[0051] In some embodiments, the method further includes at least one of:

[0052] if N PSSCHs corresponding to the same transmission block (TB) are received from a same node, not transmitting at least one of the N PSFCHs corresponding to the N PSSCHs; if N MCSt-based PSSCHs are received from the same node and the HARQ-ACK states corresponding to the N MCSt-based PSSCHs are same, not transmitting at least one of the N PSFCHs corresponding to the N MCSt-based PSSCHs; if N MCSt-based PSSCHs are received from the same node, not transmitting N PSFCHs corresponding to the N MCSt-based PSSCHs and transmitting bundled HARQ-ACK feedback information; if N MCSt-based PSSCHs are received and x PSSCHs have groupcast feedback option with ACK and NACK or unicast feedback option enabled, not transmitting x1 PSFCH among x corresponding the x PSSCHs, wherein the HARQ-ACK feedback information indicated in the x1 PSFCHs is NACK , where x is a positive integer and x1 is a positive integer not greater than x; if N MCSt-based PSSCHs are received from the same node and at least one PSSCH has groupcast feedback option with ACK and NACK or unicast feedback option enabled, not transmitting y1 PSFCH among y PSFCHs corresponding to at least one PSSCH, wherein the HARQ-ACK feedback information indicated in the y1 PSFCHs is NACK, where y is a positive integer and y1 is a positive integer not greater than y.

[0053] In some embodiments, the method further includes not transmitting at least one MCSt-based PSFCH when the determined M resources include PSFCH resources and meet the following conditions: the HARQ-ACK feedback option used by the PSSCHs corresponding to the at least one PSFCH is not NACK-only groupcast feedback option; or the PSSCHs corresponding to at least one PSFCH are from the same node, and the HARQ-ACK feedback option used by the PSSCHs corresponding to the at least one PSFCH is not NACK-only groupcast feedback option.

[0054] In some embodiments, the priority of PSFCH adjusted based on whether the PSFCH is MCSt-based includes at least one of: if the PSSCH corresponding to PSFCH is MCSt-based and other PSSCHs with the same TB as the TB corresponding to PSSCH are received, the adjusted priority of PSFCH is determined based on the adjusted PSSCH priority; if multiple MCSt-based PSSCHs are received, the adjusted priority of PSFCH is determined based on the adjusted multiple PSSCHs priorities; adjusted priority of PSFCH is determined based on the number of PSSCHs corresponding to the bundled HARQ-ACK feedback information of transmitted multiple MCSt-based PSSCHs; the adjusted priority of PSFCH is determined based on the number of MCSt-based PSSCHs.

[0055] In some embodiments, the method further includes not transmitting at least one PSFCH when the following conditions are met: multiple PSFCH resources are transmitted on one time unit, and / or the number of PSFCH resources to be transmitted on one time unit exceeds the capacity of the second node.

[0056] In some embodiments, transmitting HARQ-ACK feedback information on the determined M resources further includes indicating the HARQ-ACK feedback information corresponding to the N PSSCHs in the form of a codebook.

[0057] According to some embodiments of the present disclosure, a node device is also provided, which includes a transceiver; and a processor coupled to the transceiver and configured to perform the method of any one of the above descriptions.

[0058] The above and other features, aspects, and advantages of various embodiments of the present disclosure will be better understood with reference to the following description and appended claims. The drawings of the specification, which form a part of this disclosure, illustrate example embodiments of this disclosure, and together with the specification, serve to explain related principles. Details of one or more embodiments of the subject matter of the present invention are set forth in the accompanying drawings of the specification and the following description. Other potential features, aspects, and advantages of the subject matter of the present invention will also become clear from these descriptions, drawings, and claims.

[0059] The present disclosure provides an effective and efficient method for sidelink UE to select resources for transmitting and receiving feedback signal. Advantageous effects obtainable from the disclosure may not be limited to the above mentioned effects, and other effects which are not mentioned may be clearly understood, through the following descriptions, by those skilled in the art to which the disclosure pertains.

[0060] FIG. 1 illustrates an example wireless network 100 according to various embodiments of the present disclosure;

[0061] FIG. 2a illustrates example wireless transmission and reception paths according to the present disclosure;

[0062] FIG. 2b illustrates example wireless transmission and reception paths according to the present disclosure;

[0063] FIG. 3a illustrates an example UE according to the present disclosure;

[0064] FIG. 3b illustrates an example gNB according to the present disclosure;

[0065] FIG. 4a is a flowchart illustrating a method according to an example embodiment of the present disclosure; and

[0066] FIG. 4b is a flowchart illustrating another method according to an example embodiment of the present disclosure.

[0067] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely example. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein may be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

[0068] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0069] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0070] The term "include" or "may include" refers to the existence of a corresponding disclosed function, operation or component which may be used in various embodiments of the present disclosure and does not limit one or more additional functions, operations, or components. The terms such as "include" and / or "have" may be construed to denote a certain characteristic, number, step, operation, constituent element, component or a combination thereof, but may not be construed to exclude the existence of or a possibility of addition of one or more other characteristics, numbers, steps, operations, constituent elements, components or combinations thereof.

[0071] The term "or" used in various embodiments of the present disclosure includes any or all of combinations of listed words. For example, the expression "A or B" may include A, may include B, or may include both A and B.

[0072] Unless defined differently, all terms used herein, which include technical terminologies or scientific terminologies, have the same meaning as that understood by a person skilled in the art to which the present disclosure belongs. Such terms as those defined in a generally used dictionary are to be interpreted to have the meanings equal to the contextual meanings in the relevant field of art, and are not to be interpreted to have ideal or excessively formal meanings unless clearly defined in the present disclosure.

[0073] FIG. 1 illustrates an example wireless network 100 according to various embodiments of the present disclosure. The embodiment of the wireless network 100 shown in FIG. 1 is for illustration only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0074] The wireless network 100 includes a gNodeB (gNB) 101, a gNB 102, and a gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one Internet Protocol (IP) network 130, such as the Internet, a private IP network, or other data networks.

[0075] Depending on a type of the network, other well-known terms such as "base station" or "access point" may be used instead of "gNodeB" or "gNB". For convenience, the terms "gNodeB" and "gNB" are used in this patent document to refer to network infrastructure components that provide wireless access for remote terminals. And, depending on the type of the network, other well-known terms such as "mobile station", "user station", "remote terminal", "wireless terminal" or "user apparatus" may be used instead of "user equipment" or "UE". For convenience, the terms "user equipment" and "UE" are used in this patent document to refer to remote wireless devices that wirelessly access the gNB, no matter whether the UE is a mobile device (such as a mobile phone or a smart phone) or a fixed device (such as a desktop computer or a vending machine).

[0076] gNB 102 provides wireless broadband access to the network 130 for a first plurality of User Equipments (UEs) within a coverage area 120 of gNB 102. The first plurality of UEs include a UE 111, which may be located in a Small Business (SB); a UE 112, which may be located in an enterprise (E); a UE 113, which may be located in a WiFi Hotspot (HS); a UE 114, which may be located in a first residence (R); a UE 115, which may be located in a second residence (R); a UE 116, which may be a mobile device (M), such as a cellular phone, a wireless laptop computer, a wireless PDA, etc. GNB 103 provides wireless broadband access to network 130 for a second plurality of UEs within a coverage area 125 of gNB 103. The second plurality of UEs include a UE 115 and a UE 116. In some embodiments, one or more of gNBs 101-103 can communicate with each other and with UEs 111-116 using 5G, Long Term Evolution (LTE), LTE-A, WiMAX or other advanced wireless communication technologies.

[0077] The dashed lines show approximate ranges of the coverage areas 120 and 125, and the ranges are shown as approximate circles merely for illustration and explanation purposes. It should be clearly understood that the coverage areas associated with the gNBs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending on configurations of the gNBs and changes in the radio environment associated with natural obstacles and man-made obstacles.

[0078] As will be described in more detail below, one or more of gNB 101, gNB 102, and gNB 103 include a 2D antenna array as described in embodiments of the present disclosure. In some embodiments, one or more of gNB 101, gNB 102, and gNB 103 support codebook designs and structures for systems with 2D antenna arrays.

[0079] Although FIG. 1 illustrates an example of the wireless network 100, various changes may be made to FIG. 1. The wireless network 100 can include any number of gNBs and any number of UEs in any suitable arrangement, for example. Furthermore, gNB 101 can directly communicate with any number of UEs and provide wireless broadband access to the network 130 for those UEs. Similarly, each gNB 102-103 can directly communicate with the network 130 and provide direct wireless broadband access to the network 130 for the UEs. In addition, gNB 101, 102 and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0080] FIGs. 2a and 2b illustrate example wireless transmission and reception paths according to the present disclosure. In the following description, the transmission path 200 may be described as being implemented in a gNB, such as gNB 102, and the reception path 250 may be described as being implemented in a UE, such as UE 116. However, it should be understood that the reception path 250 may be implemented in a gNB and the transmission path 200 may be implemented in a UE. In some embodiments, the reception path 250 is configured to support codebook designs and structures for systems with 2D antenna arrays as described in embodiments of the present disclosure.

[0081] The transmission path 200 includes a channel coding and modulation block 205, a Serial-to-Parallel (S-to-P) block 210, a size N Inverse Fast Fourier Transform (IFFT) block 215, a Parallel-to-Serial (P-to-S) block 220, a cyclic prefix addition block 225, and an up-converter (UC) 230. The reception path 250 includes a down-converter (DC) 255, a cyclic prefix removal block 260, a Serial-to-Parallel (S-to-P) block 265, a size N Fast Fourier Transform (FFT) block 270, a Parallel-to-Serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

[0082] In the transmission path 200, the channel coding and modulation block 205 receives a set of information bits, applies coding (such as Low Density Parity Check (LDPC) coding), and modulates the input bits (such as using Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (QAM)) to generate a sequence of frequency-domain modulated symbols. The Serial-to-Parallel (S-to-P) block 210 converts (such as demultiplexes) serial modulated symbols into parallel data to generate N parallel symbol streams, where N is a size of the IFFT / FFT used in gNB 102 and UE 116. The size N IFFT block 215 performs IFFT operations on the N parallel symbol streams to generate a time-domain output signal. The Parallel-to-Serial block 220 converts (such as multiplexes) parallel time-domain output symbols from the Size N IFFT block 215 to generate a serial time-domain signal. The cyclic prefix addition block 225 inserts a cyclic prefix into the time-domain signal. The up-converter 230 modulates (such as up-converts) the output of the cyclic prefix addition block 225 to an RF frequency for transmission via a wireless channel. The signal can also be filtered at a baseband before switching to the RF frequency.

[0083] The RF signal transmitted from gNB 102 arrives at UE 116 after passing through the wireless channel, and operations in reverse to those at gNB 102 are performed at UE 116. The down-converter 255 down-converts the received signal to a baseband frequency, and the cyclic prefix removal block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. The Serial-to-Parallel block 265 converts the time-domain baseband signal into a parallel time-domain signal. The Size N FFT block 270 performs an FFT algorithm to generate N parallel frequency-domain signals. The Parallel-to-Serial block 275 converts the parallel frequency-domain signal into a sequence of modulated data symbols. The channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0084] Each of gNBs 101-103 may implement a transmission path 200 similar to that for transmitting to UEs 111-116 in the downlink, and may implement a reception path 250 similar to that for receiving from UEs 111-116 in the uplink. Similarly, each of UEs 111-116 may implement a transmission path 200 for transmitting to gNBs 101-103 in the uplink, and may implement a reception path 250 for receiving from gNBs 101-103 in the downlink.

[0085] Each of the components in FIGs. 2a and 2b may be implemented using only hardware, or using a combination of hardware and software / firmware. As a specific example, at least some of the components in FIGs. 2a and 2b may be implemented in software, while other components may be implemented in configurable hardware or a combination of software and configurable hardware. For example, the FFT block 270 and IFFT block 215 may be implemented as configurable software algorithms, in which the value of the size N may be modified according to the implementation.

[0086] Furthermore, although described as using FFT and IFFT, this is only illustrative and should not be interpreted as limiting the scope of the present disclosure. Other types of transforms may be used, such as Discrete Fourier transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions. It should be understood that for DFT and IDFT functions, the value of variable N may be any integer (such as 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of variable N may be any integer which is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

[0087] Although FIGs. 2a and 2b illustrate examples of wireless transmission and reception paths, various changes may be made to FIGs. 2a and 2b. For example, various components in FIGs. 2a and 2b may be combined, further subdivided or omitted, and additional components may be added according to specific requirements. Furthermore, FIGs. 2a and 2b are intended to illustrate examples of types of transmission and reception paths that may be used in a wireless network. Any other suitable architecture may be used to support wireless communication in a wireless network.

[0088] FIG. 3a illustrates an example UE 116 according to the present disclosure. The embodiment of UE 116 shown in FIG. 3a is for illustration only, and UEs 111-115 of FIG. 1 can have the same or similar configuration. However, a UE has various configurations, and FIG. 3a does not limit the scope of the present disclosure to any specific implementation of the UE.

[0089] UE 116 includes an antenna 305, a radio frequency (RF) transceiver 310, a transmission (TX) processing circuit 315, a microphone 320, and a reception (RX) processing circuit 325. UE 116 also includes a speaker 330, a processor / controller 340, an input / output (I / O) interface 345, an input device(s) 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0090] The RF transceiver 310 receives an incoming RF signal transmitted by a gNB of the wireless network 100 from the antenna 305. The RF transceiver 310 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is transmitted to the RX processing circuit 325, where the RX processing circuit 325 generates a processed baseband signal by filtering, decoding and / or digitizing the baseband or IF signal. The RX processing circuit 325 transmits the processed baseband signal to speaker 330 (such as for voice data) or to processor / controller 340 for further processing (such as for web browsing data).

[0091] The TX processing circuit 315 receives analog or digital voice data from microphone 320 or other outgoing baseband data (such as network data, email or interactive video game data) from processor / controller 340. The TX processing circuit 315 encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 310 receives the outgoing processed baseband or IF signal from the TX processing circuit 315 and up-converts the baseband or IF signal into an RF signal transmitted via the antenna 305.

[0092] The processor / controller 340 can include one or more processors or other processing devices and execute an OS 361 stored in the memory 360 in order to control the overall operation of UE 116. For example, the processor / controller 340 can control the reception of forward channel signals and the transmission of backward channel signals through the RF transceiver 310, the RX processing circuit 325 and the TX processing circuit 315 according to well-known principles. In some embodiments, the processor / controller 340 includes at least one microprocessor or microcontroller.

[0093] The processor / controller 340 is also capable of performing other processes and programs residing in the memory 360, such as operations for channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. The processor / controller 340 can move data into or out of the memory 360 as required by an execution process. In some embodiments, the processor / controller 340 is configured to execute the application 362 based on the OS 361 or in response to signals received from the gNB or the operator. The processor / controller 340 is also coupled to an I / O interface 345, where the I / O interface 345 provides UE 116 with the ability to connect to other devices such as laptop computers and handheld computers. I / O interface 345 is a communication path between these accessories and the processor / controller 340.

[0094] The processor / controller 340 is also coupled to the input device(s) 350 and the display 355. An operator of UE 116 can input data into UE 116 using the input device(s) 350. The display 355 may be a liquid crystal display or other display capable of presenting text and / or at least limited graphics (such as from a website). The memory 360 is coupled to the processor / controller 340. A part of the memory 360 can include a random access memory (RAM), while another part of the memory 360 can include a flash memory or other read-only memory (ROM).

[0095] Although FIG. 3a illustrates an example of UE 116, various changes may be made to FIG. 3a. For example, various components in FIG. 3a may be combined, further subdivided or omitted, and additional components may be added according to specific requirements. As a specific example, the processor / controller 340 may be divided into a plurality of processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). Furthermore, although FIG. 3a illustrates that the UE 116 is configured as a mobile phone or a smart phone, UEs may be configured to operate as other types of mobile or fixed devices.

[0096] FIG. 3b illustrates an example gNB 102 according to the present disclosure. The embodiment of gNB 102 shown in FIG. 3b is for illustration only, and other gNBs of FIG. 1 can have the same or similar configuration. However, a gNB has various configurations, and FIG. 3b does not limit the scope of the present disclosure to any specific implementation of a gNB. It should be noted that gNB 101 and gNB 103 can include the same or similar structures as gNB 102.

[0097] As shown in FIG. 3b, gNB 102 includes a plurality of antennas 370a-370n, a plurality of RF transceivers 372a-372n, a transmission (TX) processing circuit 374, and a reception (RX) processing circuit 376. In certain embodiments, one or more of the plurality of antennas 370a-370n include a 2D antenna array. gNB 102 also includes a controller / processor 378, a memory 380, and a backhaul or network interface 382.

[0098] RF transceivers 372a-372n receive an incoming RF signal from antennas 370a-370n, such as a signal transmitted by UEs or other gNBs. RF transceivers 372a-372n down-convert the incoming RF signal to generate an IF or baseband signal. The IF or baseband signal is transmitted to the RX processing circuit 376, where the RX processing circuit 376 generates a processed baseband signal by filtering, decoding and / or digitizing the baseband or IF signal. RX processing circuit 376 transmits the processed baseband signal to controller / processor 378 for further processing.

[0099] The TX processing circuit 374 receives analog or digital data (such as voice data, network data, email or interactive video game data) from the controller / processor 378. TX processing circuit 374 encodes, multiplexes and / or digitizes outgoing baseband data to generate a processed baseband or IF signal. RF transceivers 372a-372n receive the outgoing processed baseband or IF signal from TX processing circuit 374 and up-convert the baseband or IF signal into an RF signal transmitted via antennas 370a-370n.

[0100] The controller / processor 378 can include one or more processors or other processing devices that control the overall operation of gNB 102. For example, the controller / processor 378 can control the reception of forward channel signals and the transmission of backward channel signals through the RF transceivers 372a-372n, the RX processing circuit 376 and the TX processing circuit 374 according to well-known principles. The controller / processor 378 can also support additional functions, such as higher-level wireless communication functions. For example, the controller / processor 378 can perform a Blind Interference Sensing (BIS) process such as that performed through a BIS algorithm, and decode a received signal from which an interference signal is subtracted. A controller / processor 378 may support any of a variety of other functions in gNB 102. In some embodiments, the controller / processor 378 includes at least one microprocessor or microcontroller.

[0101] The controller / processor 378 is also capable of performing programs and other processes residing in the memory 380, such as a basic OS. The controller / processor 378 can also support channel quality measurement and reporting for systems with 2D antenna arrays as described in embodiments of the present disclosure. In some embodiments, the controller / processor 378 supports communication between entities such as web RTCs. The controller / processor 378 can move data into or out of the memory 380 as required by an execution process.

[0102] The controller / processor 378 is also coupled to the backhaul or network interface 382. The backhaul or network interface 382 allows gNB 102 to communicate with other devices or systems through a backhaul connection or through a network. The backhaul or network interface 382 can support communication over any suitable wired or wireless connection(s). For example, when gNB 102 is implemented as a part of a cellular communication system, such as a cellular communication system supporting 5G or new radio access technology or NR, LTE or LTE-A, the backhaul or network interface 382 can allow gNB 102 to communicate with other gNBs through wired or wireless backhaul connections. When gNB 102 is implemented as an access point, the backhaul or network interface 382 can allow gNB 102 to communicate with a larger network, such as the Internet, through a wired or wireless local area network or through a wired or wireless connection. The backhaul or network interface 382 includes any suitable structure that supports communication through a wired or wireless connection, such as an Ethernet or an RF transceiver.

[0103] The memory 380 is coupled to the controller / processor 378. A part of the memory 380 can include an RAM, while another part of the memory 380 can include a flash memory or other ROMs. In certain embodiments, a plurality of instructions, such as the BIS algorithm, are stored in the memory. The plurality of instructions are configured to cause the controller / processor 378 to execute the BIS process and decode the received signal after subtracting at least one interference signal determined by the BIS algorithm.

[0104] As will be described in more detail below, the transmission and reception paths of gNB 102 (implemented using RF transceivers 372a-372n, TX processing circuit 374 and / or RX processing circuit 376) support aggregated communication with FDD cells and TDD cells.

[0105] Although FIG. 3b illustrates an example of gNB 102, various changes may be made to FIG. 3b. For example, gNB 102 can include any number of each component shown in FIG. 3a. As a specific example, the access point can include many backhaul or network interfaces 382, and the controller / processor 378 can support routing functions to route data between different network addresses. As another specific example, although shown as including a single instance of the TX processing circuit 374 and a single instance of the RX processing circuit 376, gNB 102 can include multiple instances of each (such as one for each RF transceiver).

[0106] In the Long Term Evolution (LTE) technology, sidelink communication includes two main mechanisms, which are Device to Device (D2D) direct communication and Vehicle to everything (Vehicle to Vehicle / Infrastructure / Pedestrian / Network, V2X), among which V2X is designed on the basis of D2D technology, which is superior to D2D in data rate, delay, reliability and link capacity, and is the most representative sidelink communication technology in LTE technology. In 5G system, sidelink communication mainly includes vehicle to everything (V2X) communication at present.

[0107] As the evolution technology of LTE, the 5G NR system also includes the further evolution of sidelink communication. As the evolution version of LTE V2X technology, NR V2X technology is formulated in Release 16, and its performance in all aspects is superior. In Release 17, the 5G NR system is expected to further extend the application scenarios of NR V2X to other wider application scenarios, such as commercial sidelink communication and Public Safety (PS) scenarios. In Release 18, the evolution of sidelink communication includes support to directions such as unlicensed frequency band, FR2, carrier aggregation, co-channel coexistence with LTE, and technologies in other fields such as positioning.

[0108] In this embodiment of the application, the information configured by the base station, indicated by signaling, configured by the high layer and pre-configured includes a set of configuration information; also includes multiple sets of configuration information from which the UE selects a set of configuration information to use according to predefined condition; and also includes a set of configuration information containing a plurality of subsets from which the UE selects one subset to use according to predefined condition.

[0109] In the embodiment of this application, lower than a threshold can also be replaced by lower than or equal to a threshold, higher than(exceeding) a threshold can also be replaced by higher than or equal to a threshold, less than or equal to can also be replaced by less than, greater than or equal to or greater than; or vice versa.

[0110] Some technical solutions provided in the embodiment of this application are specifically described based on the V2X system, but its application scenario should not be limited to the V2X system in sidelink communication, but can also be applied to other sidelink transmission systems. For example, the design based on the V2X sub-channel in the following embodiments can also be used for the D2D sub-channel or other sub-channels of sidelink transmission. The V2X resource pool in the following embodiments can also be replaced by a D2D resource pool in other sidelink transmission systems, such as D2D.

[0111] In the embodiment of this application, when the sidelink communication system is a V2X system, the terminal or UE can be a Vehicle, an Infrastructure, a Pedestrian, and other types of terminals or UEs.

[0112] The base station in this specification can also be replaced by other nodes, such as sidelink nodes, and a specific example is the Road Side Unit (infrastructure)UE in the sidelink system. Any mechanism applicable to the base station in this embodiment can also be similarly used in the scenario where the base station is replaced by other sidelink nodes, and the description will not be repeated.

[0113] In this specification, slots can also be replaced with time units, candidate slots can also be replaced with candidate time units, and candidate single slot resources can also be replaced with candidate single time unit resources. In a specific example, the time unit can include a specific time length, such as several consecutive symbols.

[0114] The slot in this specification can be either a subframe or slot in the physical sense, or a subframe or slot the logical sense. Specifically, the subframe or slot in the logical sense is the subframe or slot corresponding to the resource pool of sidelink communication. For example, in the V2X system, the resource pool is defined by a repeated bitmap, which is mapped to a specific set of slots, the specific set of slots can be all slots, or all other slots except some specific slots (e.g., slots for transmitting Master Information Block (MIB) / System Information Block (SIB)). The slot indicated as "1" in the bitmap can be used for V2X transmission and belongs to the slot corresponding to the V2X resource pool; the slot indicated as "0" cannot be used for V2X transmission and does not belong to the slot corresponding to the V2X resource pool.

[0115] The following is a typical application scenario to illustrate the difference between physical or logical subframes or slots: when calculating the time domain gap between two specific channels / messages (such as PSSCH carrying sidelink data and PSFCH carrying corresponding feedback information), it is assumed that the gap is N slots. If physical subframes or slots are calculated , the N slots correspond to the absolute time length of N*x milliseconds in the time domain, and x is the time length of the physical slot (subframe) under the numerology of the scenario in millisecond. Otherwise, if the logical subframes or slots are calculated, take the sidelink resource pool defined by the bitmap as an example, the gap of the N slots corresponds to the N slots indicated as "1" in the bitmap, and the absolute time length of the gap changes with the specific configuration of the sidelink communication resource pool without a fixed value.

[0116] Further, the slot in this specification can be a complete slot or several symbols corresponding to sidelink communication in one slot. For example, when the sidelink communication is configured to be performed on the X1~X2 symbols of each slot, the slot in the following embodiment is the X1~X2 symbols in the slot in this scenario; alternatively, when the sidelink communication is configured as mini-slot transmission, the slot in the following embodiments is mini-slot defined or configured in the sidelink system rather than the slot in the NR system; alternatively, when the sidelink communication is configured as symbol level transmission, the slots in the following embodiments can be replaced with symbols, or can be replaced with N symbols with time domain granularity as symbol level transmission.

[0117] In order to make the purpose, technical solutions and advantages of this application clearer, the embodiment of this application will be further described in detail with the accompanying drawings.

[0118] Text and drawings are only provided as examples to help readers understand this disclosure. They are not intended and should not be construed to limit the scope of the present disclosure in any way. Although some embodiments and examples have been provided, based on the disclosure herein, it is obvious to those skilled in the art that changes can be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0119] In the LTE sidelink communication system and the NR V2X system of Release 16, the frequency domain resources for sidelink communication are usually located in the licensed frequency bands. Generally, it is assumed that there is substantially no interference from other external communication systems (such as WiFi, Bluetooth, etc.) on such frequency bands. However, for the sidelink communication system operating in the unlicensed frequency bands, it is necessary to consider the interference of other communication systems on the unlicensed bands, and it is also necessary to limit the interference of the sidelink communication to other communication systems according to regulation.

[0120] In the NR-unlicensed (NR-U) system of versions 15 and 16, Listen Before Talk (LBT) is adopted as one of the typical technologies in the unlicensed frequency bands. In this technology, a special frame structure is defined for the NR communication system in the unlicensed frequency bands, and the frame structure contains several gaps for LBT. UE and base station need to perform LBT before uplink and downlink transmission, and can transmit all kinds of wireless signals / channels normally only after LBT is passed. In this embodiment, a method for applying LBT technology to sidelink the communication system is provided.

[0121] In a communication system in unlicensed frequency bands, channel occupancy (CO) refers to the transmitting on the corresponding channel after the base station / UE performs the channel access process, and channel occupancy time (COT) refers to the total time for the base station / UE and the base station / UE sharing the channel occupancy to transmit on the corresponding channel after performing the channel access process. Both the base station and / or the sidelink UE can initialize a COT and share the COT with other base stations and / or the sidelink UE. After initializing a COT or obtaining a COT shared by base stations / other nodes, UE needs to determine the structures and positions of sidelink resources within the COT. In this embodiment, a specific method for UE to determine the structures and positions of sidelink resources within COT is explained.

[0122] In NR-Unlicensed (NR-U) technology, the structure of uplink / downlink resources within COT can be embodied by uplink / downlink burst, wherein the uplink / downlink burst is a transmission set from a base station or UE, and there is no gap exceeding a certain length. Similar to the existing definition of uplink / downlink bursts, the structure of sidelink resources within COT can also be embodied by a sidelink burst, wherein the sidelink burst is a transmission set from UE, and there is no gap exceeding a certain length (for example, 16 us). Optionally, one burst may include only transmissions from the same UE; or, one burst may include transmissions from the same or different UE. Optionally, one burst may include only one or more specific signals / channels; For example, one burst may include only physical sidelink control channel, PSCCH, and / or physical sidelink shared channel, PSSCH, another burst may include only physical sidelink feedback channel, PSFCH, or one burst may include PSCCH, PSSCH and PSFCH. Alternatively, similar to the existing discovery burst, the sidelink synchronization signal, the sidelink synchronization channel and the sidelink reference signal (which can be a specific type of reference signal / a reference signal satisfying specific conditions) correspond to the sidelink discovery burst instead of the general sidelink burst.

[0123] In the sidelink communication technology, from the perspective of resources allocation, there are two modes in the 5G sidelink communication system: resources allocation mode based on base station scheduling and resources allocation mode selected autonomously by UE. In the 5G V2X system, the resources allocation mode based on base station scheduling and the resources allocation mode selected autonomously by UE are named as mode 1 and mode 2 respectively. For the resources allocation mode 2, the method for sidelink UE selecting resources autonomously is that the UE keeps monitoring and caching the sidelink resources pool, and determines a channel sensing time window and resources selection time window according to the expected time range for transmitting the sidelink transmissions before the sidelink transmissions needed to be transmitted, performs channel sensing in the channel sensing time window, excludes the sidelink resources reserved by other sidelink UEs in the resources selection time window according to the channel sensing result, and randomly selects the sidelink resources for sidelink transmissions from the sidelink resources that are not excluded in the resources selection time window. When the mechanism operates in the unlicensed frequency bands, due to the characteristics of the unlicensed frequency bands, the mechanism needs to be modified accordingly to adapt to the uncertainty brought by the channel pre-emption mechanism based on COT sharing and LBT in the unlicensed frequency bands, and make the operation of sidelink communication in the unlicensed frequency bands not violate the restrictions of regulations.

[0124] Text and drawings are only provided as examples to help readers understand this disclosure. They are not intended and should not be construed to limit the scope of the present disclosure in any way. Although some embodiments and examples have been provided, based on the disclosure herein, it is obvious to those skilled in the art that changes can be made to the illustrated embodiments and examples without departing from the scope of this disclosure.

[0125] FIG. 4a is a flowchart illustrating a method according to an example embodiment of the present disclosure, comprising the following steps:

[0126] Step 401a: transmitting N physical sidelink shared channels (PSSCHs).

[0127] Step 402a: determining M resources for receiving Hybrid Automatic Retransmission Request Acknowledgment (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N.

[0128] Step 403a: receiving the HARQ-ACK feedback information on the determined M resources.

[0129] Step 404a: determining whether the N PSSCHs transmitted are successfully received based on the received HARQ-ACK feedback information.

[0130] FIG. 4b is a flowchart illustrating another method according to an example embodiment of the present disclosure, comprising the following steps:

[0131] Step 401b: receiving N physical sidelink shared channel (PSSCHs).

[0132] Step 402b: determining M resources for transmitting Hybrid Automatic Retransmission Request Acknowledgement (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N.

[0133] Step 403b: transmitting the HARQ-ACK feedback information on the determined M resources.

[0134] When the sidelink communication system operates on unlicensed frequency bands, it is subject to the restrictions of regulations. After selecting resources for sidelink transmission, if there is a gap exceeding a specific length before the transmission, the UE is required to perform a listen before talk (LBT) process. The transmission may be transmitted only when LBT succeed, otherwise the transmission cannot be transmitted. Therefore, when UE needs to transmit multiple transmissions (retransmissions) of a sidelink signal / channel or multiple sidelink signals / channels, in order to reduce the impact of potential LBT failures on transmission, UE can select multiple consecutive slots during resource allocation process to transmit the one / multiple sidelink signals / channels, which is also known as multi-consecutive slots transmission (MCSt), and the slots can also be replaced with other time units.

[0135] In the existing sidelink communication technologies, when the UE transmits a sidelink channel (e.g., PSCCH, PSSCH) with HARQ-ACK feedback enabled, the UE is also required to receive the HARQ-ACK feedback corresponding to the sidelink channel, which is transmitted in the PSFCH channel, and the UE determines on which PSFCH resources (which may also be referred to as PSFCH occasion) to receive the HARQ-ACK feedback corresponding to the sidelink channel through pre-set mapping criteria between PSCCH and / or PSSCH and PSFCH. Since MCSt method is not used in the existing sidelink communication technologies, the mapping between sidelink channels and PSFCH resources is also in one-to-one correspondence. Therefore, when the MCSt method is used for the sidelink control channel and / or the data channel one the unlicensed band, it is also necessary to design accordingly the corresponding PSFCH resources for the MCSt-based sidelink control channel and / or the data channel, and the method of how the UE detects and determines the corresponding HARQ-ACK information after the MCSt-based transmission.

[0136] The following UE uses multiple consecutive slots as an example when transmitting is MCSt-based. The slots may also be replaced with other time units such as OFDM symbols, mini-slots, subframes, and the like.

[0137] Alternatively, when the UE is configured to have MCSt enabled or the resource pool is configured to have MCSt enabled, the UE uses the method in the following embodiment; Otherwise, the UE uses the method in the current sidelink communication.

[0138] Embodiment 1

[0139] In an example embodiment, a first UE transmits multiple PSSCHs to a second UE on multiple consecutive slots, and may also transmit PSCCH associated with at least one PSSCH of the multiple PSSCHs. In this embodiment, multiple PSSCHs correspond to same HARQ process and / or correspond to same TB; For example, multiple PSSCHs are used to transmit multiple blind retransmissions of a same TB. The second UE may include one or more UEs, for example, when the multiple PSSCHs are unicast, the second UE includes the UE corresponding to a destination ID of the unicast. When the multiple PSSCHs are groupcast, the second UE includes one or more UEs in a UE group corresponding to destination IDs of the unicast. When the multiple PSSCHs are broadcast, the second UE includes all UEs that can receive the broadcast.

[0140] If at least one of the multiple PSSCHs has HARQ-ACK feedback enabled, the first UE will also receive HARQ-ACK feedback information from the second UE; accordingly, after receiving the at least one of the multiple PSSCHs and / or the PSCCH corresponding to the at least one of the multiple PSSCHs, the second UE also transmits HARQ-ACK information to the first UE,. The HARQ-ACK information may be used to indicate whether the PSSCH and / or the PSCCH are successfully received by the second UE, and / or may be used as a conflict indicator in inter-UE collaboration technology.

[0141] Alternatively, the first UE and / or the second UE determine the resources for receiving and / or transmitting HARQ-ACK feedback information corresponding to at least one of the multiple PSSCHs through at least one of the following methods:

[0142] Determining PSFCH occasions corresponding to the multiple PSSCHs based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, and receiving and / or transmitting HARQ-ACK feedback information on the PSFCH occasions corresponding to the multiple PSSCHs. Alternatively, the one of the PSFCH occasions corresponding to the multiple PSSCHs includes at least one of: a PSFCH occasion corresponding to the earliest PSSCH; a PSFCH occasion corresponding to the latest PSSCH; if the second UE successfully decodes a PSSCH for the first time, the PSFCH occasion corresponding to the PSSCH; the PSFCH occasion with the highest frequency domain index among the multiple PSFCH occasions; the PSFCH occasion with the lowest frequency domain index among the multiple PSFCH occasions;

[0143] Determining PSFCH occasions corresponding to the multiple PSSCHs based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, and receiving and / or transmitting HARQ-ACK feedback information on at least one of PSFCH occasions corresponding to the multiple PSSCHs. Alternatively, the at least one of PSFCH occasions corresponding to the multiple PSSCHs includes: when N PSFCH occasions among PSFCH occasions corresponding to multiple PSSCHs are within the same slot , and / or when N PSFCH occasions are within the same slot and the number of PSFCHs that the second UE needs to transmit on the slot exceeds the UE capability, receiving and / or transmitting HARQ-ACK feedback information on N1 of the N PSFCH occasions; alternatively, N1=1, or N1 is a positive integer such that the number of PSFCHs that the second UE needs to transmit on the slot on which the N PSFCHs occasions are located does not exceed the UE capability;

[0144] Determining PSFCH occasions corresponding to the multiple PSSCHs based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, and receiving and / or transmitting HARQ-ACK feedback information on each of PSFCH occasions corresponding to the multiple PSSCHs.

[0145] The first UE indicates to the second UE the resources for HARQ-ACK feedback information, the resources include at least one of PSCCH resources, PSSCH resources, and PSFCH resources. HARQ-ACK feedback information corresponding to at least one of the multiple PSSCHs transmitted by the second UE is received on the resources for HARQ-ACK feedback information; accordingly, the second UE transmits HARQ-ACK feedback information corresponding to at least one of the multiple PSSCHs on the resource indicated by the first UE for HARQ-ACK feedback information. Alternatively, the first UE also indicates resources for HARQ-ACK feedback information when transmitting at least one of the multiple PSSCHs, including indicating the resources for the HARQ-ACK feedback information in the SCI when transmitting SCI (including first-order SCI and / or second-order SCI) associated with the at least one of the multiple PSSCHs. Alternatively, the first UE indicates a resource for HARQ-ACK feedback information, the resources include at least one of the following types: HARQ-ACK feedback information corresponding to at least one of the multiple PSSCHs; HARQ-ACK feedback information corresponding to all of the multiple PSSCHs; when the resources are indicated in the SCI, HARQ-ACK feedback information corresponding to the PSSCH associated with the SCI; when the resources are indicated in the SCI, HARQ-ACK feedback information corresponding to at least one or all PSSCHs among the multiple PSSCHs no later than the PSSCHs associated with the SCI ;

[0146] The second UE indicates to the first UE the resources for HARQ-ACK feedback information transmitted to the first UE, as well as the resources indicating the PSSCH and / or PSCCH corresponding to the HARQ-ACK feedback information, and transmits HARQ-ACK feedback information on the resources for HARQ-ACK feedback information. The HARQ-ACK feedback information corresponds to the PSSCH and / or PSCCH transmitted by the first UE on the PSSCH and / or PSCCH resources corresponding to the HARQ-ACK feedback information indicated by the second UE. Accordingly, the first UE detects the resource pool and receives HARQ-ACK feedback information transmitted by the second UE. Based on the PSSCH and / or PSCCH resources corresponding to the HARQ-ACK feedback information indicated by the second UE, which PSSCH and / or PSCCH transmitted by the first UE the HARQ-ACK feedback information corresponds to are determined. Alternatively, the second UE indicates the resources for HARQ-ACK feedback information in SCI (including first-order SCI and / or second-order SCI), and / or the PSSCH and / or PSCCH resources corresponding to the HARQ-ACK feedback information. Alternatively, the HARQ-ACK feedback information corresponds to one of the multiple PSSCHs transmitted by the first UE and / or one PSCCH associated with the one of the multiple PSSCHs, and / or the HARQ-ACK feedback information corresponds to more than one of the multiple PSSCHs transmitted by the first UE and / or one or more PSCCH associated with more than one of the multiple PSSCHs. Alternatively, the HARQ-ACK feedback information carries ACK / NACK information in the form of sequence parameters on the PSFCH resource; and / or the HARQ-ACK feedback information is indicated in the SCI (first-order SCI and / or second-order SCI) on PSCCH and / or PSSCH resources or indicated in new physical layer signaling used to indicate HARQ-ACK feedback information, including in the form of a codebook.

[0147] Alternatively, when the second UE transmits HARQ-ACK feedback information on at least one of or each of PSFCH occasions corresponding to the multiple PSSCHs, if the HARQ-ACK feedback information includes at least one ACK, then: set the HARQ-ACK feedback information transmitted on at least one or each PSFCH occasion as ACK, or, set the HARQ-ACK feedback information on the PSFCH occasions on the same slot as the earliest PSFCH occasion among the PSFCH occasions with HARQ-ACK feedback information as ACK and / or on the PSFCH occasions after the earliest PSFCH occasion as ACK; or, transmit ACK on one of the at least one or each PSFCH occasion, suspend transmitting on other PSFCH occasions, or transmit ACK on one of the PSFCH occasions on the same slot as the earliest PSFCH occasion among the PSFCH occasions with HARQ-ACK feedback information as ACK and / or on the PSFCH occasions after the earliest PSFCH occasion, suspend transmitting on the other occasions of the PSFCH occasions on the same slot as the earliest PSFCH occasion among the PSFCH occasions with HARQ-ACK feedback information as ACK and / or on the PSFCH occasions after the earliest PSFCH occasion.

[0148] Embodiment 2

[0149] In another example embodiment, the first UE transmits multiple PSSCHs to the second UE on multiple consecutive slots, and may also transmit PSCCH associated with at least one of the multiple PSSCHs. In this embodiment, the multiple PSSCHs correspond to multiple HARQ processes and / or correspond to multiple TBs. The second UE may include one or more UEs, for example, when at least one of the multiple PSSCHs is unicast, the second UE includes the UE corresponding to the destination ID of the unicast. When at least one of the multiple PSSCHs is groupcast, the second UE includes one or more UEs in the UE group corresponding to the destination IDs of the unicast. When at least one of the multiple PSSCHs is broadcast, the second UE includes all UEs of the multiple PSSCHs that can receive the broadcast. When the destination IDs of multiple PSSCHs are different, the second UE can include all UEs each corresponding to the destination IDs of the multiple PSSCHs.

[0150] In this embodiment, there may be more than one PSSCH corresponding to the same TB among the multiple PSSCHs. For this situation, the method in the scenario where multiple PSSCHs correspond to one TB in the previous embodiment can also be used similarly on the more than one PSSCH corresponding to one TB.

[0151] If at least one of the multiple PSSCHs has HARQ-ACK feedback enabled, the first UE will also receive HARQ-ACK feedback information from the second UE; accordingly, after receiving at least one of the multiple PSSCHs and / or the PSCCHs corresponding to at least one of the multiple PSSCHs, the second UE also transmits HARQ-ACK information to the first UE. The HARQ-ACK information may be used to indicate whether PSSCH and / or PSCCH are successfully received by the second UE, and / or may be used as a conflict indicator in inter-UE collaboration technology. In this embodiment, for the convenience of description, the PSSCHs with HARQ-ACK feedback enabled among the multiple PSSCHs are referred to as a first PSSCH set, and the PSCCHs associated with the PSSCHs with HARQ-ACK feedback enabled are referred to as a first PSCCH set.

[0152] Alternatively, the first UE and / or the second UE determine the resources for receiving and / or transmitting HARQ-ACK feedback information corresponding to at least one PSSCH in the first PSSCH set by at least one of the following methods:

[0153] Determining PSFCH occasions corresponding to the PSSCH in the first PSSCH set based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, and receiving and / or transmitting HARQ-ACK feedback information on one of the PSFCH occasions corresponding to the PSSCHs in the same TB. Alternatively, if the same TB corresponds to multiple PSSCHs, one of the PSFCH occasions corresponding to the multiple PSSCHs includes at least one of: the PSFCH occasion corresponding to the earliest PSSCH among the multiple PSSCHs, the PSFCH occasion corresponding to the latest PSSCH, the PSFCH occasion corresponding to the PSSCH on which the second UE successfully decodes the TB for the first time; the PSFCH occasion with the highest frequency domain index, and the PSFCH occasion with the lowest frequency domain index. For the PSSCH on which the second UE successfully decodes the TB , since the first UE cannot determine when the second UE decodes successfully, in this method, the first UE receives HARQ-ACK feedback information on PSFCHs corresponding to all PSSCHs corresponding to the TB, and the second UE transmits HARQ-ACK feedback information on the PSFCH occasions corresponding to the PSSCHs on which the TB is successfully decoded;

[0154] Determining PSFCH occasions corresponding to the PSSCH in the first PSSCH set based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, if multiple PSFCH occasions are determined to be on the same slot, bundled PSFCHs is transmitted on at least one of the multiple PSFCH occasions; and / or, determining PSFCH occasions corresponding to the PSSCH in the first PSSCH set based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, if the determined PSFCH occasion includes multiple PSFCH occasions, bundled PSFCHs is transmitted on at least one of the multiple PSFCH occasions. The at least one PSFCH occasion may be at least one of: the PSFCH occasion with the highest / lowest frequency domain index among the multiple PSFCH occasions, the PSFCH occasion whose corresponding PSSCH is the earliest / latest among the PSSCHs corresponding to the multiple PSFCH occasions, the PSFCH occasion whose corresponding PSSCH has the highest priority among the PSSCHs corresponding to the multiple PSFCH occasions, a randomly selected PSFCH occasion among the multiple PSFCH occasions. The HARQ-ACK state of the bundled PSFCHs includes at least one of: if the HARQ-ACK feedback information corresponding to multiple PSFCH occasions includes at least one ACK (including ACKs that will not be actually transmitted in the NACK-only groupcast feedback option), the HARQ-ACK feedback information transmitted on the bundled PSFCHs is ACK; alternatively, if the HARQ-ACK feedback information corresponding to multiple PSFCH occasions includes at least one NACK, then the HARQ-ACK feedback information transmitted on the bundled PSFCHs is ACK;

[0155] Determining PSFCH occasions corresponding to the PSSCH in the first PSSCH set based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, if the multiple PSFCH occasions are determined to be on the same slot, PSFCH will not be transmitted on at least one of the multiple PSFCH occasions. Alternatively, if the feedback information transmitted on multiple PSFCH occasions determined by the second UE includes multiple ACKs, ACK may be transmitted on one of the PSFCH occasions corresponding to the multiple ACKs, and the transmissions on other PSFCH occasion corresponding to the multiple ACKs are suspended; and / or, if the feedback information transmitted on multiple PSFCH occasions determined by the second UE includes multiple NACKs, NACK may be transmitted on one of the PSFCH occasions corresponding to the multiple NACKs and transmissions on other PSFCH occasions corresponding to the multiple NACKs are suspended; and / or, if the feedback information transmitted on multiple PSFCH occasions determined by the second UE includes multiple NACKs, and the multiple NACKs includes NACK corresponding to the PSSCHs with NACK-only feedback option enabled, NACK may be transmitted on the PSFCH occasions corresponding to NACKs corresponding to the PSSCHs with NACK-only groupcast feedback option enabled, and NACK may also be transmitted on one of the remaining PSFCH occasions corresponding to remaining NACKs, and the transmissions on other PSFCH occasions corresponding to the multiple NACKs are suspended. Alternatively, if the second UE has multiple PSFCHs to transmit on one slot, and / or if the number of PSFCHs that the second UE needs to transmit on one slot exceeds the UE capability, the above method is used. Accordingly, alternatively, if the first UE determines that multiple PSFCH occasions corresponding to the first PSSCH set are on the same slot, and at least one ACK is received on the multiple PSFCH occasions, and no ACK or NACK is received on a subset of the multiple PSFCH occasions, the HARQ-ACK feedback of the PSSCH corresponding to the PSFCH occasion on which no ACK or NACK received is determined as ACK; and / or, if the first UE determines that multiple PSFCH occasions corresponding to the first PSSCH set are on the same slot, and alternatively, if at least one NACK is received on the multiple PSFCH occasions, and no ACK or NACK is received on a subset of the multiple PSFCH occasions, the HARQ-ACK feedback of the PSSCH corresponding to the PSFCH occasion on which no ACK or NACK received is determined as NACK; and / or, if the first UE determines that multiple PSFCH occasions corresponding to the first PSSCH set are on the same slot, and alternatively, if at least one NACK is received on the multiple PSFCH occasions and no ACK or NACK is received on a subset of the multiple PSFCH occasions, the HARQ-ACK feedback of the PSSCH corresponding to the PSFCH occasion on which no ACK or NACK received is determined as ACK when the NACK-only groupcast feedback option is used, otherwise, the HARQ-ACK feedback of the PSSCH corresponding to the PSFCH occasion on which no ACK or NACK received is determined as NACK when the groupcast or unicast feedback options for ACK and NACK are used;

[0156] Determining PSFCH occasions corresponding to the PSSCH in the first PSSCH set based on the mapping criteria between PSSCH resources and / or PSCCH resources and PSFCH resources, and receiving and / or transmitting HARQ-ACK feedback information on each corresponding PSFCH occasions;

[0157] The first UE indicates to the second UE the resources for HARQ-ACK feedback information, the resources include at least one of PSCCH resources, PSSCH resources, and PSFCH resources. The first UE receives HARQ-ACK feedback information transmitted by the second UE on the resources for HARQ-ACK feedback information, the HARQ-ACK feedback information corresponds to at least one PSSCH in the first PSSCH set; accordingly, the second UE transmits HARQ-ACK feedback information corresponding to at least one PSSCH in the first PSSCH set on the resource indicated by the first UE for HARQ-ACK feedback information. Alternatively, the first UE also indicates resources for HARQ-ACK feedback information when transmitting at least one PSSCH in the first PSSCH set, including indicating resources for HARQ-ACK feedback information in SCIs when transmitting SCIs associated with at least one PSSCH (including first-order SCI and / or second-order SCI). Alternatively, the first UE indicates resources for HARQ-ACK feedback information, the resources include at least one of the following types: HARQ-ACK feedback information corresponding to at least one PSSCH in the first PSSCH set; HARQ-ACK feedback information corresponding to all PSSCHs in the first PSSCH set; when the resources for HARQ-ACK feedback information are indicated in the SCI, the HARQ-ACK feedback information corresponding to the PSSCH associated with the SCI; when the resources for HARQ-ACK feedback information are indicated in the SCI, the HARQ-ACK feedback information corresponding to at least one or all of the PSSCHs no later than the PSSCH associated with the SCI among the multiple PSSCHs;

[0158] The second UE indicates to the first UE the resources for HARQ-ACK feedback information transmitted to the first UE, as well as the resources indicating the PSSCH and / or PSCCH corresponding to the HARQ-ACK feedback information, and transmits HARQ-ACK feedback information on the resources for HARQ-ACK feedback information. The HARQ-ACK feedback information corresponds to the PSSCH and / or PSCCH transmitted by the first UE on the resources for the PSSCH and / or PSCCH corresponding to the HARQ-ACK feedback information indicated by the second UE. Accordingly, the first UE detects the resource pool and receives HARQ-ACK feedback information transmitted by the second UE. Based on the PSSCH and / or PSCCH resources corresponding to the HARQ-ACK feedback information indicated by the second UE, which PSSCH and / or PSCCH transmitted by the first UE the HARQ-ACK feedback information corresponds to are determined. Alternatively, the second UE indicates the resources for HARQ-ACK feedback information in the SCI (including first-order SCI and / or second-order SCI), and / or the resources of PSSCH and / or PSCCH corresponding to the HARQ-ACK feedback information. Alternatively, the HARQ-ACK feedback information corresponds to a PSSCH in the first PSSCH set transmitted by the first UE and / or a PSCCH associated with one PSSCH in the first PSSCH set, and / or the HARQ-ACK feedback information corresponds to more than one PSSCH in the first PSSCH set transmitted by the first UE and / or one or more PSCCH associated with more than one PSSCH in the first PSSCH set. Alternatively, the HARQ-ACK feedback information carries ACK / NACK information in the form of sequence parameters on the PSFCH resource; and / or the HARQ-ACK feedback information is indicated in the SCI (first-order SCI and / or second-order SCI) on PSCCH and / or PSSCH resources or indicated in new physical layer signaling used to indicate HARQ-ACK feedback information, including in the form of a codebook.

[0159] The above example mainly illustrates the HARQ-ACK feedback information. When the HARQ-ACK feedback information is transmitted on PSFCH, the method used can also be used similarly for UE collaboration information (such as conflict indication) transmitted on PSFCH.

[0160] Embodiment 3

[0161] Since PSFCH resources can be configured periodically in the resource pool, PSFCH resources included in one slot including PSFCH resources are FDM and correspond to PSSCH resources in multiple previous slots. Therefore, there may be situations where UE needs to transmit multiple PSFCHs simultaneously to provide feedback to multiple previous PSSCHs. But there is an upper limit to the number of PSFCHs that UE can transmit simultaneously, which usually depends on the UE capability. When the number of PSFCHs that UE needs to transmit exceeds the UE capability, the UE needs to deprioritize the transmissions of some of the PSFCHs . The deprioritized transmissions of PSFCH may be dropped or cancelled. Accordingly, other un-deprioritized PSFCH transmissions may be prioritized.

[0162] In the following embodiments, UE suspending the transmission of a signal / channel may also be replaced by UE canceling the transmission of the signal / channel, or replaced by UE not transmitting the signal / channel, or deprioritizing the transmission of the signal / channel.

[0163] In an example embodiment, UE determines the PSFCHs to be transmitted simultaneously according to the priority of the PSFCH (and / or the priority of the PSSCH corresponding to the PSFCH, which may be similarly replaced in this embodiment without repeated), whether the PSSCH corresponding to the PSFCH is MCSt-based transmission, and / or the HARQ-ACK feedback option used by the PSSCH corresponding to the PSFCH, and / or the content of the HARQ-ACK feedback information indicated by the PSFCH. The priority of PSFCH is the priority of its corresponding PSSCH. If one PSFCH corresponds to multiple PSSCHs, the priority of the PSFCH is the highest among the corresponding PSSCHs (i.e. the one with the lowest priority value, and the smaller the priority value in the sidelink system, the higher the priority).

[0164] In this embodiment, a third UE receives PSCCH and / or PSSCH from a fourth UE and needs to transmit PSFCH to the fourth UE. When the third UE has multiple PSFCHs to transmit, different PSFCHs may be transmitted to different fourth UEs (such as fourth UE-A, fourth UE-B, etc.), so the fourth UE may be a single UE or a set of multiple UEs.

[0165] Alternatively, if the third UE has multiple PSFCHs, to be transmitted on the same slot or the same OFDM symbol, and the number of PSFCHs exceeds the UE capability; and / or, if the third UE has multiple PSFCHs to be transmitted on the same slot or the same OFDM symbol, and the transmission power of the UE cannot meet the requirement of at least one PSFCH, then the third UE uses at least one of the following methods to suspend at least one PSFCH:

[0166] Prioritizing suspending the PSFCH with lower priority, and prioritizing suspending at least one MCSt-based PSFCH among PSFCHs with the same priorities;

[0167] Prioritizing suspending at least one MCSt-based PSFCH. When the remaining PSFCHs still needs to be suspended, prioritizing suspending the PSFCH with lower priority;

[0168] Based on whether PSFCH is MCSt-based, adjusting the priorities of the PSFCHs. Based on the adjusted priorities, prioritizing suspending the PSFCH with lower priority.

[0169] After suspending at least one PSFCH, if the number of remaining PSFCHs no longer exceeds the UE capability and / or the UE transmission power can meet the requirements of each of the remaining PSFCHs, the UE transmits the remaining PSFCHs.

[0170] Furthermore, the method of suspending at least one MCSt-based PSFCH by the third UE includes at least one of:

[0171] If the third UE receives multiple PSSCHs corresponding to the same TB, and the multiple PSSCHs are from the same fourth UE, then at least one of the PSFCHs corresponding to the multiple PSSCHs is suspended. Alternatively, among the PSFCHs corresponding to the PSSCHs corresponding the same TB, the third UE suspends other PSFCHs other than the one corresponding to the latest PSSCH in the time domain (which may also be replaced with the earliest, random, or highest priority one). Alternatively, if the HARQ-ACK feedback information indicated by the PSFCHs corresponding to the PSSCHs corresponding the same TB is different (for example, some PSFCHs indicate NACK and some PSFCHs indicate ACK), the content indicated by the PSFCHs is determined based on whether the TB are successfully received when transmitting the PSFCHs by the third UE, rather than that the content indicated by the PSFCHs is determined based on the reception state of each PSSCH separately. For example, if the third UE receives PSSCH-1A, PSSCH-1B, PSSCH-2A and the NDI indication of 1A is toggled while the NDI of 1B remains unchanged, or if 1A and 1B indicate the same HARQ process index and 1A and 1B are MCSt-based, it is determined that 1A and 1B correspond to the same TB; if the HARQ-ACK feedback corresponding to 1A is NACK and the HARQ-ACK feedback corresponding to 1B is ACK, then UE suspends the transmission of the PSFCH corresponding to PSSCH-1A, transmits the PSFCHs corresponding to PSSCH-1B and PSSCH-2A, and sets the information indicated by PSSCH-1A as ACK;

[0172] If the third UE receives multiple MCSt-based PSSCHs (for example, the multiple PSSCHs are consecutive in the time domain and / or SCI indicates that the multiple PSSCHs are MCSt-based), and the multiple PSSCHs are from the same fourth UE, and the HARQ-ACK states corresponding to the multiple MCSt-based PSSCHs are the same (for example, all ACK or all NACK), then at least one of the PSFCHs corresponding to the multiple MCSt-based PSSCHs is suspended. Alternatively, among multiple MCSt-based PSSCHs that correspond to the same HARQ-ACK state, the third UE suspends other PSFCHs other than the one corresponding to the latest PSSCH in the time domain (which may also be replaced by the earliest, random, and highest priority one);

[0173] If the third UE receives MCSt-based PSSCHs (such as multiple PSSCHs that are consecutive in the time domain and / or the SCI indicates that the multiple PSSCHs are MCSt-based), and the multiple PSSCHs are from the same fourth UE, the PSFCHs corresponding to the multiple MCSt-based PSSCHs is suspended and bundled HARQ-ACK feedback is transmitted to the fourth UE. Specifically, when the HARQ-ACK state corresponding to at least one PSSCH is NACK, NACK is transmitted to the fourth UE, otherwise ACK is transmitted to the fourth UE. Alternatively, the third UE transmits bundled HARQ-ACK feedback on at least one PSFCH corresponding to the multiple PSSCHs, which may be the PSFCH with the highest / lowest frequency domain index, and / or the PSFCH corresponding to the earliest / latest PSFCH in the time domain, or a randomly selected PSFCH;

[0174] If the third UE receives MCSt-based PSSCHs (for example, multiple PSSCHs are consecutive in the time domain, and / or the SCI indicates that the multiple PSSCHs are MCSt-based), and alternatively, the multiple PSSCHs are from the same fourth UE, and at least one PSSCH has groupcast with ACK and NACK or unicast feedback options enabled, then prioritizing suspending the PSFCH with the indicated HARQ-ACK feedback information being NACK among the PSFCHs corresponding to at least one PSSCH;

[0175] If the third UE receives MCSt-based PSSCHs (for example, multiple PSSCHs are consecutive in the time domain, and / or the SCI indicates that the multiple PSSCHs are MCSt-based), and alternatively the multiple PSSCHs are from the same fourth UE, and at least one PSSCH has the NACK-only groupcast feedback option enabled, the PSFCH corresponding to the at least one PSSCH is not suspended when using the other methods mentioned above to suspend the PSFCH.

[0176] Alternatively, if the third UE suspends the transmission of PSFCH corresponding to at least one of the multiple MCSt-based PSSCHs, and / or if the third UE receives one or more MCSt-based PSSCHs (alternatively, with HARQ-ACK feedback enabled), then the third UE dynamically indicates the HARQ-ACK information corresponding to the multiple PSSCHs, including indicating on the resource indicated by the fourth UE to the third UE for dynamically indicating HARQ-ACK information, and / or the third UE selects resources to indicate the HARQ-ACK information corresponding to the multiple PSSCHs on its own and indicates the relationship between the HARQ-ACK information and its corresponding PSSCHs to the fourth UE. Alternatively, the resources used to indicate the HARQ-ACK information include at least one resource of PSCCH, PSSCH, and PSFCH.

[0177] Alternatively, the third UE dynamically indicates the HARQ-ACK feedback information corresponding to multiple MCSt-based PSSCHs to the fourth UE, including indicating the HARQ-ACK information corresponding to the multiple PSSCHs in the form of a codebook.

[0178] Alternatively, the method for adjusting the priority of PSFCH based on whether PSFCH is MCSt-based include at least one of the following:

[0179] If the PSSCH corresponding to PSFCH is MCSt-based, and the third UE receives multiple other PSSCHs corresponding to the same TB as the PSSCH corresponding to from the fourth UE, then: increase the priority of at least one of the PSSCHs corresponding to the TB, and / or decrease the priority of at least one of the PSSCHs corresponding to the TB, and adjust the priority of the PSFCH accordingly based on the adjusted priority of the PSSCH; and / or, increase the priority of PSFCH corresponding to at least one of the PSSCHs corresponding to TB, and / or decrease the priority of PSFCH corresponding to at least one of the PSSCH corresponding to TB. Alternatively, at least one of the PSSCHs and / or the PSFCH corresponding to at least one of the PSSCHs includes at least one of: the PSFCH with the highest / lowest frequency domain index and / or its corresponding PSSCH, the earliest / latest PSCCH in the time domain and / or its corresponding PSFCH, the randomly selected PSCCH and / or its corresponding PSFCH;

[0180] If the third UE receives multiple MCSt-based PSSCHs from the fourth UE, then: increase the priority of at least one of the multiple MCSt-based PSSCHs, and / or decrease the priority of at least one of the multiple MCSt-based PSSCHs, and adjust the priority of the PSFCH accordingly based on the adjusted priority of the PSSCH; and / or, increase the priority of PSFCH corresponding to at least one of the multiple MCSt-based PSSCHs, and / or decrease the priority of PSFCH corresponding to at least one of the multiple MCSt-based PSSCHs. Alternatively, at least one of the PSSCHs and / or the PSFCH corresponding to at least one of the PSSCHs includes at least one of: the PSFCH with the highest / lowest frequency domain index and / or its corresponding PSSCH, the earliest / latest PSCCH in the time domain position and / or its corresponding PSFCH, the randomly selected PSCCH and / or its corresponding PSFCH;

[0181] If the third UE transmits the bundled HARQ-ACK feedback of the multiple MCSt-based PSSCHs to the fourth UE, the priority of the bundled HARQ-ACK feedback is the same as the highest priority PSSCH among the corresponding PSSCH. Alternatively, when the number of PSSCHs corresponding to the bundled HARQ-ACK feedback is high (such as when the threshold is exceeded), the priority of the bundled HARQ-ACK feedback is increased. Alternatively, the more PSSCHs corresponding to the bundled HARQ-ACK feedback, the greater the increase in priority of the bundled HARQ-ACK feedback;

[0182] According to the adjustment of the number of MCSt-based PSSCH, the more MCSt-based PSSCH, the greater the increase in the priority of PSFCH, and vice versa; and / or, for multiple MCSt-based PSSCH, the greater the number of PSSCHs and / or corresponding PSFCHs that have been deprioritized, and / or the more PSFCHs that have been suspended, the greater the increase in priority when increasing the priority of PSFCH, and vice versa;

[0183] When adjusting the priority of MCSt-based PSSCH and / or its corresponding PSFCH using other methods mentioned above, the priority of PSSCH and / or its corresponding PSFCH using NACK-only groupcast feedback option is not adjusted.

[0184] Accordingly, the fourth UE transmits PSCCH and / or PSSCH to the third UE (similarly, the third UE may be a set of one or more UEs) and needs to receive HARQ-ACK feedback of PSCCH and / or PSSCH with HARQ-ACK feedback enabled from the third UE. When the fourth UE does not receive corresponding HARQ-ACK feedback at the PSFCH occasion corresponding to at least one PSCCH and / or PSSCH with HARQ-ACK feedback enabled in multiple MCSt-based PSCCH and / or PSSCH, the fourth UE uses at least one of the following methods to determine the state of the HARQ-ACK feedback of the PSCCH and / or PSSCH and / or whether the PSCCH and / or PSSCH are successfully received (all of the following are illustrated by determining whether the state of the HARQ-ACK feedback is ACK or NACK, where the state of the HARQ-ACK feedback as ACK may be replaced by that the PSCCH and / or PSSCH was successfully received, and the state of the HARQ-ACK feedback as NACK may be replaced by that the PSCCH and / or PSSCH was not successfully received):

[0185] If the fourth UE transmits multiple MCSt-based PSSCHs corresponding to the same TB to the third UE (such as multiple blind retransmissions of the same TB) and receives at least one corresponding PSFCH from the third UE, the HARQ-ACK feedback state of the multiple PSSCHs is determined based on the HARQ-ACK feedback state of the at least one PSFCH; if the HARQ-ACK feedback state of at least one PSFCH includes multiple states and the multiple states includes at least one ACK, the HARQ-ACK feedback state of the multiple PSSCHs is determined as ACK;

[0186] If the fourth UE transmits multiple MCSt-based PSSCHs to the third UE and receives at least one corresponding PSFCH from the third UE, then the HARQ-ACK feedback state of the multiple PSSCHs is determined based on the HARQ-ACK feedback state of the at least one PSFCH. Alternatively, when the HARQ-ACK feedback state is NACK, the HARQ-ACK feedback state of the multiple PSSCHs is determined based on the HARQ-ACK feedback state of the at least one PSFCH. Alternatively, this method is only used if the multiple PSSCHs do not include PSSCHs that use NACK-only groupcast feedback option; and / or, this method is only used for PSSCHs that do not use the NACK-only groupcast feedback option among the multiple PSSCHs, and a non-MCSt-based method is used for PSSCHs that use the NACK-only groupcast feedback option. Alternatively, this method is only used when the HARQ-ACK feedback received for at least one PSFCH is for a specific PSFCH (such as at least one PSFCH with the highest / lowest frequency domain index, and at least one PSFCH whose corresponding PSSCH is at least one PSSCH with the earliest / latest time domain position among multiple PSSCHs based on MCSt), otherwise the HARQ-ACK feedback state of the multiple PSSCHs is determined using the non-MCSt-based method. Alternatively, this method is only used when the fourth UE and / or the third UE and / or the resource pool is configured to have the bundled HARQ-ACK feedback enabled, or this method may be used when the fourth UE and / or the third UE and / or the resource pool is configured or not.

[0187] In various embodiments of this specification, a method is used to select at least one PSFCH resource for HARQ-ACK feedback among multiple PSFCH resources corresponding to multiple PSSCHs, includes: selecting the earliest / latest PSSCH among the PSSCH resources, selecting the highest / lowest indexed PSFCH resource among the PSSCH resource, selecting the PSFCH resource corresponding to the PSSCH with the highest priority, and randomly selecting the PSFCH resource, and other methods, may be further combined arbitrarily to select at least one PSFCH resource for HARQ-ACK feedback. For example, the first / second UE selects at least one PSFCH resource with the highest / lowest index corresponding to at least one PSSCH with the highest priority among multiple PSSCHs for HARQ-ACK feedback; for example, the first UE randomly selects at least one PSFCH resource for HARQ-ACK feedback from the PSFCH resources corresponding to the PSSCH with the highest priority; for example, the first UE selects the PSFCH resource with the earliest PSSCH corresponding to the PSFCH resource with the lowest index for HARQ-ACK feedback.

[0188] In various embodiments of this specification, the limitation of PSFCHs corresponding to the multiple PSSCHs on the same time unit may be applied to the case where the multiple PSSCHs are subsets of several PSSCHs transmitted on consecutive time units. For example, if the first UE transmits 8 PSSCHs over 8 consecutive slots, with PSFCH corresponding to PSSCH 1-4 on slot a and PSFCH corresponding to PSSCH 5-8 on slot b, the method in each embodiment may be used for PSSCH 1-4 and PSSCH 5-8, respectively, and PSSCH 1-4 may be used as multiple PSSCHs in the above methods and PSSCH 5-8 may be used as multiple PSSCHs in the above methods, respectively.

[0189] In various embodiments of this specification, UE obtains configuration information related to MCSt and / or scheduling information related to MCSt from the base station; wherein, the scheduling information and / or configuration information includes configuration information and / or scheduling information related to at least one of PSSCH, PSCCH, and PSFCH. Similarly, the base station transmits configuration information related to MCSt and / or scheduling information related to MCSt to the UE; wherein, the scheduling information and / or configuration information includes configuration information and / or scheduling information related to at least one of PSSCH, PSCCH, and PSFCH.

[0190] In sidelink communication systems, SCI is used to indicate control information for sidelink transmission from the sidelink UEs to other UEs, while DCI is used to indicate control information for sidelink transmission from the base station to the sidelink UEs that transmit the sidelink transmission. The current design of SCI and DCI is mainly based on the control information used for sidelink communication on licensed frequency bands. After the application scenarios of sidelink communication systems are expanded to unlicensed frequency bands and / or based on sidelink positioning, additional control information is introduced. Therefore, the design of SCI and DCI also needs to be adjusted accordingly. The following provides a design method for DCI format and / or SCI format, which may be used for sidelink communication systems on unlicensed frequency bands and / or for sidelink based positioning systems.

[0191] In an example embodiment, the first UE transmits an SCI to one or more second UEs, the SCI may be used to share the channel occupancy time (COT) initialized by the first UE (or may be replaced with channel occupancy (CO), which is similar to the following and will not be repeated) with the second UE, and / or indicate the control information of the PSSCH transmitted by the first UE to the second UE. This method may be understood as: the SCI format of the SCI used to schedule PSSCH and share COT is the same as the SCI format of the SCI used to schedule PSSCH. The SCI format corresponding to the SCI may be the first order SCI format and / or the second order SCI format.

[0192] Alternatively, the SCI format includes a field indicating COT sharing related information, and the existence and / or length of the field is not altered by whether the SCI format is used for COT sharing. When the SCI format is used to indicate control information of PSSCH and not to indicate information COT sharing, the field related to shared information is set to a preset / (pre)configured value.

[0193] Alternatively, the SCI format includes a field indicating COT sharing related information, the existence and / or length of the field is determined based on whether the SCI format is used for COT sharing. Furthermore, when the SCI format indicates the COT sharing related information, the field of COT sharing related information exists, and / or the length of the field of COT sharing related information is a preset / configured first length, and / or the value of the field of COT sharing related information is set based on the state of the shared COT. When the SCI format does not indicate COT sharing related information, the field of COT sharing related information does not exist, and / or the length of the field of COT sharing related information is a preset / configured second length, and / or the value of the field of COT sharing related information is a preset / configured value.

[0194] Alternatively, whether the SCI format is used for COT sharing may be determined by a field in the SCI format, the field indicates whether the SCI format indicates COT sharing related information (for example, the values of '0' and '1' in 1 bit indicate that the SCI format indicates COT sharing related information and the SCI format does not indicate COT sharing related information respectively). Alternatively, if the SCI format including a field indicating COT sharing related information is a second order SCI format, the field is indicated in its associated first order SCI format (after adding this indication, the method may also be considered based on whether the SCI format is used for COT sharing using a different second order SCI format). This method may be used for the field of COT sharing related information, based on whether the field may exist or not, and / or whether the first length and the second length are same or different, without imposing any restrictions on whether the value of the field of COT sharing related information will change based on the value of the field. Alternatively, if the SCI format including the field indicating COT sharing related information is a second-order SCI format, the field is indicated in the second-order SCI format. This method may be used in the case where the field of COT sharing related information will exist regardless of the value of the field, and / or in the case where the first length and the second length are same, without imposing any restrictions on whether the values of the field of COT sharing related information will change based on the value of the field.

[0195] In another example embodiment, the first UE transmits an SCI to one or more second UEs, using the first SCI format when the SCI is used to indicate control information of the PSSCH transmitted by the first UE to the second UE and COT sharing related information or when the SCI is used to indicate COT sharing related information, and using the second SCI format when the SCI is used to indicate control information of the PSSCH transmitted by the first UE to the second UE. Wherein, the second SCI format may be at least one SCI format on the licensed frequency bands, such as at least one of SCI formats 1-A, 2-A, 2-B, 2-C; or the second SCI format may also be a new SCI format designed for unlicensed frequency bands. Since the SCI format in sidelink communication includes two orders, optionally, the first SCI format may include the first and / or second order SCI format, and / or the second SCI format corresponds to the first and / or second order SCI format. In a specific example, when the SCI is used to indicate control information of the PSSCH transmitted by the first UE to the second UE and COT sharing related information, or when the SCI is used to indicate COT sharing related information, the SCI includes the first order SCI format 1-X and the second order SCI format 2-Y. When the SCI is used to indicate control information of the PSSCH transmitted by the first UE to the second UE, the SCI includes the first order SCI format 1-X and the second order SCI format 2-Z. Wherein, SCI format 1-X includes indication field for the second order SCI format.

[0196] Alternatively, at least one SCI format on the licensed frequency bands may also be used on the unlicensed frequency bands, and based on preset / pre-configured / high layer or base station configured information, certain field related to the unlicensed frequency bands may or may not exist in the SCI format.

[0197] Alternatively, COT sharing related information includes at least one of: the CAPC level corresponding to the COT (which may also be understood as the CAPC level used to initialize the COT), the ID of the UE shared with the COT, the time domain resources corresponding to the COT, and the frequency domain resources corresponding to the COT.

[0198] Time domain resources may be indicated by at least one of the starting position (which may be determined by reference point + offset, where the reference point may be preset / pre-configured, and the offset may be indicated by SCI), length (which may be the number of slots), and ending position (which may be determined by reference point + offset, and the reference point may be preset / pre-configured or the starting position). The length of COT further includes the total length of the COT (i.e. the length from the starting position to the ending position) and / or the remaining length of the COT (i.e. the length from the time domain position where the SCI indicating the information is located to the ending position of the COT). Alternatively, when UE indicates COT sharing related information on other resources after the starting position in the COT, time domain resources corresponding to the COT may be indicated by indicating the remaining length of the COT; and / or, when UE indicates COT sharing related information at the starting position of the COT (such as the first slot in the COT), the time domain resources corresponding to the COT may be indicated by indicating the total length of the COT and / or the remaining length of the COT, and the value of the total length and the value of he remaining length may be same. Alternatively, when UE indicates COT sharing related information on any resource in the COT, time domain resources corresponding to the COT may be indicated by indicating the remaining length of the COT.

[0199] Frequency domain resources may be indicated based on field to the RB set, and / or determined based on frequency domain resource allocation information of the PSSCH. Further, the information of the subchannels used by PSSCH is indicated by the frequency domain resource allocation information in SCI, and the frequency domain resources of COT are the sum of RB set containing at least one subchannel in the subchannels.

[0200] If the content indicated in the SCI format includes both COT sharing related information and control information of PSSCH, the same type of information corresponding to both may be indicated through different fields; for example, the CAPC level corresponding to COT and the CAPC level corresponding to PSSCH may be different and indicated by different fields. And / or, the same type of information corresponding to both may be indicated by the same field; for example, the SCI format indicates the CAPC level, the CAPC level is the CAPC level corresponding to COT and the CAPC level corresponding to PSSCH. And / or, the SCI format indicates the information corresponding to one of the two, which may be used to determine the information corresponding to the other; for example, the SCI format indicates the subchannels and / or RB set used by PSSCH, and the RB set occupied by COT is determined based on the subchannels and / or RB set used by PSSCH. For example, it may be the RB set where the subchannels used by PSSCH are located, or the same as the RB set used by PSSCH. For the method where the same type of information corresponding to both is indicated by different fields and by the same field both, a specific example is that UE1 transmits the PSSCH to UE2 and shares the COT initialized by UE1 to both UE2 and UE3, the ID of UE2 is indicated in a field (which may be the destination ID field) and the ID of UE3 is indicated in another field (which may be an additional ID field) in the SCI.

[0201] The content of COT sharing related information and the method for SCI format indicating content may be used for any of the above embodiments.

[0202] In an example embodiment, the first UE initializes the COT and reports the information of the COT to the base station; and / or, the first UE obtains the shared COT and reports the information of the COT to the base station. Alternatively, the second UE obtains scheduling information for sidelink transmission from the base station, including information about the COT.

[0203] Alternatively, the first UE reports COT information to the base station through PUCCH and / or UCI, the PUCCH and / or UCI may use a new format that includes at least one of:

[0204] At least one of the COT sharing related information mentioned above;

[0205] The COT is either the COT initialized by the first UE or shared by other UEs;

[0206] If the COT is a shared COT, the ID of the UE that initialized the COT;

[0207] The IDs of other UEs share the COT, which may be the same as the UE ID fields (such as destination ID and / or additional ID fields) indicating COT sharing related information.

[0208] Alternatively, when the UE operates on unlicensed frequency bands, the UE is configured to use the new format or use the new format according to preset criteria; and / or, when UE operates on the licensed frequency bands, the UE is configured to use the existing PUCCH / UCI format on the licensed frequency bands according to preset criteria. The advantage of this method is that the PUCCH / UCI format used by UE may be determined by whether the UE operates on unlicensed frequency bands, as UE does not use both formats simultaneously, thereby reducing blind detection at the base station.

[0209] In an example embodiment, the first UE receives a DCI transmitted by the base station, and the information indicated by the DCI includes scheduling information for SL-PRS. Alternatively, different DCI formats are used when DCI indicates information for positioning sidelink resource in a dedicated resource pool and when DCI indicates information for positioning and communicating sidelink resource in a shared resource pool. Alternatively, the two resource pools may be distinguished by the resource pool index field in the DCI format. For example, when the resource pool indicated by the resource pool index field is the dedicated resource pool for positioning, UE decodes the DCI in the DCI format corresponding to the dedicated resource pool for positioning, and vice versa. Alternatively, the two DCI formats are distinguished by dedicated indicator fields for different DCI formats.

[0210] Alternatively, when one slot may be used to transmit multiple TDMs and / or TDM and SL-PRS multiplexed based on comb, the scheduling information of SL-PRS indicated in DCI includes the position of the resources used by SL-PRS in one slot. Similarly, when UE indicates control information for SL-PRS in SCI, the information can be included.

[0211] Furthermore, when one slot includes N SL-PRS occasions of TDMs and each occasion may be used for the transmission of one SL-PRS, the information of the SL-PRS indicated in SCI and / or DCI includes the index (which may be 1~N or 0~N-1)of the resources used by the SL-PRS in N occasion.

[0212] Furthermore, when one slot includes one SL-PRS occasion of TDM (i.e. does not support SL-PRS multiplexing in TDM within one slot) and each occasion includes M SL-PRS resources multiplexed based on comb (which may be used for transmission of up to M SL-PRS), the information of the SL-PRS indicated in SCI and / or DCI includes the index (which may be 1-M or 0-M-1) of the resources used by the SL-PRS in M resources multiplexed based on comb .

[0213] Furthermore, when one slot includes N SL-PRS occasions of TDMs and each occasion includes M SL-PRS resources multiplexed based on comb (which may be used for transmission of up to M SL-PRS), the information of SL-PRS indicated in SCI and / or DCI includes the index (which may be 1-N or 0-N-1)of the resource used by the SL-PRS in N occasions, and / or the index (which may be 1-M or 0-M-1) of the resource used by the SL-PRS in M resources multiplexed based on comb and / or index (which may be 1~M*N or 0~M*N-1) of the resource used by the SL-PRS in a total of N * M SL-PRS resources.

[0214] In an example embodiment, the time-frequency resources of one slot and at least one subchannel include multiple SL-PRS resources multiplexed in TDM and / or multiplexed in comb. The frame structure of the resources may be preset and / or pre-configured / high-level or base station configured, and further, the position of the AGC symbols may be determined based on a maximum number of SL-PRSs multiplexed in the time-frequency resources of one time slot and at least one subchannel, and / or a frequency domain size of the PSCCH, and / or the subchannel size.

[0215] Alternatively, in one slot containing PSCCH and SL-PRS, the PSCCH occasion is located at the beginning N symbols in the slot, and SL-PRS is located on the remaining symbols. There may be one AGC symbol before the first symbol where the PSCCH occasion is located, and there may be one gap symbol after the last symbol where the PSCCH occasion is located. There may be one AGC symbol before the first symbol where each SL-PRS or multiple SL-PRS multiplexed in comb on the same symbol set is located, and there may be one gap symbol after the last symbol where each SL-PRS or multiple SL-PRS multiplexed in comb on the same symbol set is located.

[0216] Alternatively, in one slot containing PSCCH and SL-PRS, the slot is divided into N symbol sets, each symbol set may be used for transmission of at least one SL-PRS or for transmission of one or more SL-PRS multiplexed in comb. The PSCCH occasion is located on the starting N symbols in each symbol set, and SL-PRS is located on the remaining symbols. In each symbol set, there may be one AGC symbol before the first symbol where the PSCCH occasion is located, and there may be one gap symbol after the last symbol where the PSCCH occasion is located. In each symbol set, there may be one AGC symbol before the first symbol where each SL-PRS or multiple SL-PRS multiplexed in comb on the same symbol set is located, and there may be one gap symbol after the last symbol where each SL-PRS or multiple SL-PRS multiplexed in comb on the same symbol set is located.

[0217] Alternatively, UE determines the position of the AGC symbol, including:

[0218] Determining based on preset criteria / pre-configuration / high-level configured / base station configured, including determining one of the two slot structures mentioned above;

[0219] Determining based on the maximum number of SL-PRS multiplexed in a time-frequency resource of one slot and at least one subchannel, and / or the frequency domain size of PSCCH, and / or the subchannel size. Furthermore, when the sum of the frequency domain size of the PSSCH corresponding to the maximum number of SL-PRS multiplexed in the time-frequency resources of one slot and at least one subchannel does not exceed the subchannel size, determining that the PSCCH occasion is located on the starting N symbols in the slot. Otherwise, it is determining that the slot is divided into several symbol sets, and the PSCCH occasion is located on the starting N symbols in each symbol set.

[0220] The maximum number of SL-PRS multiplexed in the time-frequency resources of one slot and at least one subchannel may be M * N, where N is the maximum number of SL-PRS multiplexed in TDM in one slot, and M is the maximum number of SL-PRS multiplexed in comb on the same symbol set. Accordingly, the sum of the frequency domain size of the corresponding PSSCH is M*N*K, where K is the frequency domain size of one PSCCH occasion.

[0221] For sidelink communication systems on unlicensed frequency bands, when UE selects resources on its own, corresponding enhancements can also be designed to address the issue of mutual blocking between UEs caused by listen before talk (LBT), in order to avoid the problem of one UE's transmission interfering with the LBT process of another UE. The following provides a corresponding method.

[0222] In an example embodiment, during the resource selection process at the physical layer, if the first UE detects resources reserved by other UEs and is able to share the COT initialized by the first UE with the reserved resources, the first UE prioritizing selecting the candidate resources on the slot before the reserved resources in the candidate resource set when generating a candidate resource set. In another example embodiment, during the resource selection process at the physical layer, if the first UE detects resources reserved by other UEs, the first UE avoids selecting N consecutive slots before the reserved resources when generating the candidate resource set, N is equal to 0 or a positive integer, such as {0, 1, 2}. The latter method may be used for scenarios where the first UE cannot share its initialized COT with the reserved resources.

[0223] When the first UE prioritizing selecting the candidate resources on the slot before the reserved resources, two candidate resource sets are generated. The first set corresponds to the prioritizing selected candidate resources on the slot before the reserved resources, and the second set corresponds to other candidate resources selected during the resource selection process. UE determines the minimum size of the candidate resource set that needs to be reported to the high layer based on configured and / or preset thresholds, and uses at least one of the following methods:

[0224] When the size of the first set is greater than or equal to the minimum size, reporting the first set;

[0225] When the total size of the first and second sets is greater than or equal to the minimum size, add resources from the second set to the first set until the size of the first set equals the minimum size, and reporting the first set;

[0226] When the total size of the first and second sets is less than the minimum size, increasing the RSRP threshold during the resource selection process, and based on the increased threshold, re-determining the first and second sets (such as re-executing the resource selection process using the above method), and re-determining the relevant set sizes.

Claims

1.A method performed by a first node in a communication system, comprising:transmitting N physical sidelink shared channels (PSSCHs);determining M resources for receiving Hybrid Automatic Retransmission Request Acknowledgment (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N;receiving the HARQ-ACK feedback information on the determined M resources; anddetermining whether the transmitted N PSSCHs are successfully received based on the received HARQ-ACK feedback information.2.The method according to claim 1, wherein determining M resources for receiving HARQ-ACK feedback information comprises one of:determining that M physical sidelink feedback channel (PSFCH) resources among the N PSFCH resources corresponding to the N PSSCHs are resources for receiving HARQ-ACK feedback information;determining M resources for receiving HARQ-ACK feedback information by using a sensing based and / or random selection based resource determination method;determining M resources for receiving HARQ-ACK feedback information based on a second indication received for resource for HARQ-ACK feedback information,wherein the M resources determined based on sensing and / or random selection, and the M resources determined based on the second indication, include at least one of physical sidelink control channel (PSCCH) resources, PSSCH resources, and PSFCH resources.3.The method according to claim 2, wherein the M PSFCH resources at least comprise one of:no more than M PSFCH resources corresponding to the earliest PSSCH among the N PSSCHs;no more than M PSFCH resources corresponding to the latest PSSCH among the N PSSCHs;no more than M PSFCH resources with the highest frequency domain index among the N PSFCH resources;no more than M PSFCH resources with the lowest frequency domain index among the N PSFCH resources;no more than M PSFCH resources randomly selected from the N PSFCH resources.4.The method according to claim 2, wherein the M PSFCH resources further comprise:no more than M PSFCH resources corresponding to the PSSCH with the highest priority among the N PSSCHs.5.The method according to claim 1, wherein determining whether the transmitted N PSSCHs are successfully received based on the received HARQ-ACK feedback information comprises:if the received HARQ-ACK feedback information corresponding to the transmitted N PSSCHs includes at least one ACK, determining that the transmitted N PSSCHs are successfully received; otherwise, determining that the N transmitted PSSCHs are not successfully received.6.The method according to claim 1 or 5, further comprising: among the transmitted N PSSCHs, for the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received, determining that the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received is successfully received when a first condition set is met,wherein, the first condition set comprises:the N PSFCH resources corresponding to the transmitted N PSSCHs are on the same time unit;at least one ACK is received on the N PSFCH resources corresponding to the transmitted N PSSCHs.7.The method according to claim 1 or 5, further comprising: among the transmitted N PSSCHs, for the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received, determining that the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received is not successfully received when a second condition set is met,wherein, the second condition set comprises:the N PSFCH resources corresponding to the transmitted N PSSCHs are on the same time unit.8.The method according to claim 5, wherein the second condition set further comprises:among the transmitted N PSSCHs, the PSSCH corresponding to the PSFCH resources on which no ACK or NACK was received uses groupcast feedback option or unicast feedback option of ACK and NACK.9.A method performed by a second node in a communication system, comprising:receiving the N physical sidelink shared channels (PSSCHs);determining M resources for transmitting Hybrid Automatic Retransmission Request Acknowledgement (HARQ-ACK) feedback information, wherein M, N are positive integers greater than or equal to 1 and M is not greater than N; andtransmitting the HARQ-ACK feedback information on the determined M resources.10.The method according to claim 9, wherein transmitting the HARQ-ACK feedback information on the determined M resources further includes, when the determined M resources include PSFCH resources, performing at least one of:if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple ACKs, prioritizing transmitting ACKs on k1 PSFCH resource among k PSFCH resources corresponding to the multiple ACKs, and / or not transmitting PSFCHs on other k-k1 PSFCH resources among the k PSFCH resources corresponding to the multiple ACKs, where k is a positive integer and k1 is a positive integer not greater than k;if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple NACKs, prioritizing transmitting NACKs on p1 PSFCH resources among p PSFCH resources corresponding to the multiple NACKs, and / or not transmitting PSFCHs on other p-p1 PSFCH resources among the p PSFCH resources corresponding to the multiple NACKs, where p is a positive integer and p1 is a positive integer not greater than p;if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple NACKs and the multiple NACKs include the NACKs corresponding to the PSSCH resources with NACK-only feedback option enabled, prioritizing transmitting NACKs on q1 PSFCH resources corresponding to the NACKs corresponding to the PSSCH with NACK-only groupcast feedback option enabled, and / or not transmitting PSFCHs on other q-q1 PSFCH resources among q PSFCH resources corresponding to the multiple NACKs, where q is a positive integer and q1 is a positive integer not greater than q;if the HARQ-ACK feedback information corresponding to the N PSSCHs includes multiple NACKs and the multiple NACKs include the NACKs corresponding to the PSSCH resources with NACK-only feedback option enabled, prioritizing transmitting NACKs on q1 PSFCH resources corresponding to the NACKs corresponding the PSSCH with NACK-only groupcast feedback option enabled, and prioritizing transmitting NACKs on q2 PSFCH resources among the PSFCH resources corresponding to the remaining NACKs, and / or not transmitting PSFCH on other q-q1-q2 PSFCH resources among q PSFCH resources corresponding to the multiple NACKs, where q is a positive integer and q1, q2 are positive integers not greater than q.11.The method according to claim 9, further comprising, when the determined M resources include PSFCH resources, using at least one of:the transmission of PSFCH with higher priority is prioritized over the transmission of PSFCH with lower priority, and / or, for the transmissions of PSFCH with same priorities, the transmission of PSFCH not based on multi-consecutive slots transmission (MCSt) is prioritized over the transmission of MCSt-based PSFCH;not transmitting at least one MCSt-based PSFCH, and when prioritization is still required for the remaining PSFCHs, the transmission of PSFCH with higher priority is prioritized over the transmission of PSFCH with lower priority;based on the adjusted priority, not transmitting PSFCH with lower priority, wherein the adjusted priority includes the priority of PSFCH adjusted based on whether the PSFCH is MCSt-based.12.The method according to claim 11, wherein the priority of PSFCH adjusted based on whether the PSFCH is MCSt-based includes at least one of:if the PSSCH corresponding to PSFCH is MCSt-based and other PSSCHs with the same transmission block (TB) as the TB corresponding to PSSCH are received, the adjusted priority of PSFCH is determined based on the adjusted PSSCH priority;if multiple MCSt-based PSSCHs are received, the adjusted priority of PSFCH is determined based on the adjusted multiple PSSCHs priorities;the adjusted priority of PSFCH is determined based on the number of PSSCHs corresponding to the bundled HARQ-ACK feedback information of transmitted multiple MCSt-based PSSCHs;the adjusted priority of PSFCH is determined based on the number of MCSt-based PSSCHs.13.The method according to claim 9, further comprising at least one of:if N PSSCHs corresponding to the same TB are received from a same node, not transmitting at least one of the N PSFCHs corresponding to the N PSSCHs;if N MCSt-based PSSCHs are received from the same node and the HARQ-ACK states corresponding to the N MCSt-based PSSCHs are same, not transmitting at least one of the N PSFCHs corresponding to the N MCSt-based PSSCHs;if N MCSt-based PSSCHs are received from the same node, not transmitting N PSFCHs corresponding to the N MCSt-based PSSCHs and transmitting bundled HARQ-ACK feedback information;if N MCSt-based PSSCHs are received and x PSSCHs have groupcast feedback option with ACK and NACK or unicast feedback option enabled , not transmitting x1 PSFCH among x corresponding the x PSSCHs, wherein the HARQ-ACK feedback information indicated in the x1 PSFCHs is NACK , where x is a positive integer and x1 is a positive integer not greater than x;if N MCSt-based PSSCHs are received from the same node and at least one PSSCH has groupcast feedback option with ACK and NACK or unicast feedback option enabled, not transmitting y1 PSFCH among y PSFCHs corresponding to at least one PSSCH, wherein the HARQ-ACK feedback information indicated in the y1 PSFCHs is NACK, where y is a positive integer and y1 is a positive integer not greater than y.14.The method according to claim 9, further comprising not transmitting at least one MCSt-based PSFCH when the determined M resources include PSFCH resources and meet the following conditions:the HARQ-ACK feedback option used by the PSSCHs corresponding to the at least one PSFCH is not NACK-only groupcast feedback option; orthe PSSCHs corresponding to at least one PSFCH are from the same node, and the HARQ-ACK feedback option used by the PSSCHs corresponding to the at least one PSFCH is not NACK-only groupcast feedback option.15.A node device, including:a transceiver; anda processor coupled with the transceiver and configured to perform the method of any one of claims 1-14.

Images