Communication method, terminal equipment and network equipment

Abstract

The invention provides a communication method, terminal equipment and network equipment. The method comprises the following steps that: before communication is carried out through a first sidewalk resource, terminal equipment sends a first CPE (Customer Premise Equipment); wherein the length of the first CPE is the first length. Before using the first sidewalk communication resource for communication, the terminal device may occupy a channel through the first CPE until the terminal device may perform sidewalk communication through the first sidewalk resource. For example, through the first CPE, other communication equipment can be prevented from occupying a channel where the terminal equipment has successful LBT, so that the terminal equipment can normally perform sidewalk communication.

Description

Communication method, terminal device, and network device Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a communication method, a terminal device, and a network device. Background Art

[0002] In sidelink communications over unlicensed spectrum, even after successful listen-before-talk (LBT) communication, sidelink communication may still be unavailable. For example, in some sidelink communications, resources for sidelink communication begin at the time slot boundary, meaning that sidelink signals or channels can only be transmitted from that time slot boundary. Therefore, during the period between successful LBT and the time slot boundary, other communication devices in different systems may preempt the channel, preventing the terminal device from conducting sidelink communication at the time slot boundary.

[0003] Summary of the Invention

[0004] The present application provides a communication method, a terminal device, and a network device. The following introduces various aspects of the present application.

[0005] In a first aspect, a communication method is provided, including: before communicating through a first sidelink resource, a terminal device sends a first extended cyclic prefix (CPE); wherein the length of the first CPE is a first length.

[0006] In a second aspect, a communication method is provided, including: a network device sends first information to a terminal device; wherein the first information is used to indicate a first length, the first length is used to indicate the length of a first CPE, and the first CPE is the CPE sent by the terminal device before communicating through a first sideline resource.

[0007] According to a third aspect, a terminal device is provided, comprising: a first sending unit, configured to send a first CPE before communicating through a first sideline resource; wherein the length of the first CPE is a first length.

[0008] In a fourth aspect, a network device is provided, comprising: a second sending unit, used to send first information to a terminal device; wherein, the first information is used to indicate a first length, the first length is used to indicate the length of a first CPE, and the first CPE is the CPE sent by the terminal device before communicating through a first sideline resource.

[0009] In a fifth aspect, a terminal device is provided, comprising a processor and a memory, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes part or all of the steps in the method of the first aspect.

[0010] In a sixth aspect, a network device is provided, comprising a processor, a memory, and a transceiver, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the network device executes part or all of the steps in the method of the second aspect.

[0011] In a seventh aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal device and / or network device. In another possible design, the system may also include other devices that interact with the terminal device or network device in the solution provided in the embodiment of the present application.

[0012] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program enables a terminal device and / or a network device to execute part or all of the steps in the methods of the above aspects.

[0013] In a ninth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a terminal device and / or a network device to perform some or all of the steps of the methods described in each of the above aspects. In some implementations, the computer program product may be a software installation package.

[0014] In the tenth aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the methods of the above aspects.

[0015] Before using the first sideline communication resource for sideline communication, the terminal device may occupy the channel through the first CPE until the terminal device can perform sideline communication through the first sideline resource. It is understandable that the first CPE can prevent other communication devices from occupying the channel, thereby allowing the terminal device to perform sideline communication normally. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIG1 is a diagram illustrating an example of a system architecture of a wireless communication system to which an embodiment of the present application may be applied.

[0017] FIG2 is an example diagram of a side communication scenario within network coverage.

[0018] FIG3 is an example diagram of a side communication scenario with partial network coverage.

[0019] FIG4 is an example diagram of a side communication scenario outside network coverage.

[0020] FIG5 is a diagram illustrating an example of a side communication scenario with a central control node.

[0021] FIG6 is an example diagram of a sideline communication method based on broadcasting.

[0022] FIG7 is an example diagram of a unicast-based sideline communication method.

[0023] FIG8 is an example diagram of a side communication method based on multicast.

[0024] FIG9 is a diagram showing an example of a time slot structure of certain side-by-side communication systems (e.g., an NR-V2X system).

[0025] FIG10 is an example diagram showing changes in the available OFDM symbols for the PSSCH in different time slots.

[0026] FIG11 is an example diagram of time-frequency resources occupied by the second-order SCI in a time slot.

[0027] FIG12 is a schematic diagram of a DMRS pattern of a PSCCH.

[0028] FIG13 is a schematic diagram of the time domain positions of four DMRS symbols when the number of PSSCH symbols is 14.

[0029] FIG14 is an example diagram of a single-symbol DMRS frequency domain type 1. FIG.

[0030] FIG15 is an example diagram of the time-frequency position of an SL CSI-RS.

[0031] FIG16 is an example diagram showing a channel occupancy time obtained by a communication device after successful LBT on a channel of an unlicensed spectrum, and signal transmission using resources within the channel occupancy time.

[0032] Figure 17 is a schematic flowchart of a communication method provided in an embodiment of the present application.

[0033] FIG18 is an example diagram of a method for indicating CPE length provided in an embodiment of the present application.

[0034] FIG19 is an example diagram of a scenario in which different terminal devices select different CPE lengths.

[0035] Figure 20 is an example diagram of another method for indicating CPE length provided in an embodiment of the present application.

[0036] FIG21(a), FIG21(b), and FIG21(c) are example diagrams of the relationships between different resource pools.

[0037] Figure 22 is a schematic structural diagram of a terminal device provided in an embodiment of the present application.

[0038] Figure 23 is a schematic structural diagram of a network device provided in an embodiment of the present application.

[0039] Figure 24 is a schematic structural diagram of a device for communication provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] The technical solution in this application will be described below with reference to the accompanying drawings.

[0041] Communication System

[0042] Figure 1 is a diagram illustrating the system architecture of a wireless communication system 100 used in an embodiment of the present application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 located within the coverage area.

[0043] Optionally, the wireless communication system 100 may include multiple network devices and the coverage area of ​​each network device may include other numbers of terminal devices, which is not limited in this embodiment of the present application.

[0044] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiments of the present application.

[0045] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0046] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the terminal device can be used to act as a base station. For example, the terminal device can act as a scheduling entity that provides sidelink signals between terminal devices in vehicle-to-everything (V2X) or device-to-device (D2D) communication. For example, a cellular phone and a car communicate with each other using sidelink signals. Cell phones and smart home devices can communicate with each other without relaying the communication signal through a base station. Optionally, the terminal device can be used to act as a base station.

[0047] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, a modem or a chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device (D2D), vehicle-to-vehicle (V2V), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, and a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form adopted by the network equipment.

[0048] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0049] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device includes a CU and a DU. The gNB may also include an AAU.

[0050] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0051] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0052] Sideline communication under different network coverage conditions

[0053] Sidelink communication (or sidelink transmission) refers to a communication technology based on sidelink (SL). Sidelink communication can be, for example, D2D or V2X. Sidelink communication supports direct communication and data transmission between terminal devices. Direct communication data transmission between terminal devices can achieve higher spectrum efficiency and lower transmission latency. For example, the Internet of Vehicles system uses sidelink communication technology.

[0054] In side communication, according to the network coverage of the terminal device, side communication can be divided into side communication within the network coverage, side communication with partial network coverage, side communication outside the network coverage and side communication controlled by the central node.

[0055] Figure 2 illustrates an example scenario for sidelink communication within network coverage. In the scenario shown in Figure 2, both terminal devices 120a are within the coverage of network device 110. Therefore, both terminal devices 120a can receive configuration signaling from network device 110 (configuration signaling in this application can also be replaced by configuration information) and determine the sidelink configuration based on the configuration signaling from network device 110. After both terminal devices 120a have configured their sidelinks, sidelink communication can proceed on the sidelink.

[0056] Figure 3 is an example diagram of a sidelink communication scenario with partial network coverage. In the scenario shown in Figure 3, terminal device 120a performs sidelink communication with terminal device 120b. Terminal device 120a is located within the coverage range of network device 110, so terminal device 120a can receive the configuration signaling of network device 110 and determine the sidelink configuration based on the configuration signaling of network device 110. Terminal device 120b is located outside the network coverage and cannot receive the configuration signaling of network device 110. In this case, terminal device 120b can determine the sidelink configuration based on pre-configuration information and / or information carried in the physical sidelink broadcast channel (PSBCH) sent by terminal device 120a within the network coverage. After both terminal device 120a and terminal device 120b perform sidelink configuration, sidelink communication can be performed on the sidelink.

[0057] Figure 4 illustrates an example scenario for sidelink communication outside of network coverage. In the scenario shown in Figure 4, both terminal devices 120b are outside of network coverage. In this scenario, both terminal devices 120b can determine the sidelink configuration based on pre-configured information. After both terminal devices 120b have configured their sidelinks, sidelink communication can proceed over the sidelink.

[0058] Figure 5 illustrates an example scenario for sideline communication with a central control node. In the scenario shown in Figure 5, multiple terminal devices 120b may constitute a communication group. This communication group may include a central control node. In some cases, the central control node may serve as a cluster header (CH) terminal device. The central control node may have one or more of the following functions: establishing the communication group, managing the joining and leaving of group members, coordinating resources, allocating sideline transmission resources to other terminal devices, receiving sideline feedback information from other terminal devices, and coordinating resources with other communication groups.

[0059] Sideline communication mode

[0060] Certain standards or protocols (such as the 3rd Generation Partnership Project (3GPP)) define two sideline communication modes (or transmission modes): a first mode and a second mode.

[0061] In the first mode, the resources of the terminal device (the resources mentioned in this application may also be referred to as transmission resources, time-frequency resources) are allocated by the network device. The terminal device can send data on the side link according to the resources allocated by the network device. The network device can allocate resources for a single transmission to the terminal device, or it can allocate resources for semi-static transmission to the terminal device. This first mode can be applied to scenarios covered by a network device, such as the scenario shown in Figure 2 above. In the scenario shown in Figure 2, the terminal device 120a is within the network coverage of the network device 110, so the network device 110 can allocate resources used in the side transmission process to the terminal device 120a.

[0062] In the second mode, the terminal device can autonomously select one or more resources from a resource pool (RP). The terminal device can then perform side transmission based on the selected resources. For example, in the scenario shown in FIG4 , the terminal device 120b is located outside the cell coverage area. Therefore, the terminal device 120b can autonomously select resources from a pre-configured resource pool for side transmission. Alternatively, in the scenario shown in FIG2 , the terminal device 120a can also autonomously select one or more resources from a resource pool configured by the network device 110 for side transmission.

[0063] Data transmission method of side communication

[0064] Some sidewalk communication systems (such as LTE-V2X) support broadcast-based data transmission (hereinafter referred to as broadcast transmission). For broadcast transmission, the receiving terminal device can be any terminal device around the transmitting terminal device. Taking Figure 6 as an example, terminal device 1 is the transmitting terminal device, and the receiving terminal device corresponding to the transmitting terminal device is any terminal device around terminal device 1, such as terminal devices 2 to terminal devices 6 in Figure 6.

[0065] In addition to broadcast transmission, some communication systems also support unicast-based data transmission (hereinafter referred to as unicast transmission) and / or multicast-based data transmission (hereinafter referred to as multicast transmission). For example, NR-V2X aims to support autonomous driving. Autonomous driving places higher requirements on data exchange between vehicles. For example, data exchange between vehicles requires higher throughput, lower latency, higher reliability, wider coverage, and more flexible resource allocation. Therefore, to improve the performance of data exchange between vehicles, NR-V2X introduces unicast and multicast transmission.

[0066] For unicast transmission, there is typically only one receiving terminal device. For example, in Figure 7, unicast transmission occurs between terminal devices 1 and 2. Terminal device 1 can be the sending terminal device, and terminal device 2 can be the receiving terminal device, or alternatively, terminal device 1 can be the receiving terminal device, and terminal device 2 can be the sending terminal device.

[0067] For multicast transmission, the receiving terminal device can be a terminal device within a communication group, or it can be a terminal device within a certain transmission distance. Taking Figure 7 as an example, terminal devices 1, 2, 3, and 4 form a communication group. If terminal device 1 sends data, the other terminal devices in the group (terminal devices 2 through 4) can all be receiving terminal devices.

[0068] Sideline communication system frame structure

[0069] A timeslot may include channels such as the physical sidelink control channel (PSCCH), the physical sidelink shared channel (PSSCH), and the physical sidelink feedback channel (PSFCH). These channels will be described in detail below and will not be repeated here.

[0070] Figure 9 shows an example of a time slot structure for certain sidelink communication systems (e.g., NR-V2X systems). Figure 9(a) shows an example of a time slot structure in which the physical sidelink feedback channel (PSFCH) is not included in the time slot. Figure 9(b) shows an example of a time slot structure in which the PSFCH is included in the time slot.

[0071] As shown in Figure 9, in the time domain, the PSCCH can start from the second sidelink symbol of the time slot and occupy 2 or 3 orthogonal frequency division multiplexing (OFDM) symbols. In the frequency domain, it can occupy {10, 12 15, 20, 25} physical resource blocks (PRB / RB). In order to reduce the complexity of the terminal device's blind detection of the PSCCH, only one number of PSCCH symbols and PRBs can be configured in a resource pool. In addition, the subchannel is the minimum granularity of PSSCH resource allocation in some sidelink communication systems (such as the NR-V2X system). Therefore, the number of PRBs occupied by the PSCCH must be less than or equal to the number of PRBs contained in a subchannel in the resource pool to avoid additional restrictions on PSSCH resource selection or allocation.

[0072] In the time domain, the PSSCH can start from the second side symbol of the time slot. The last time domain symbol in the time slot is the guard period (GP) symbol (also called the gap (GAP) symbol), and the remaining symbols can be mapped to the PSSCH. The first side symbol in the time slot can be a repetition of the second side symbol. The receiving terminal device can use the first side symbol as an automatic gain control (AGC) symbol, and the data on this symbol is usually not used for data demodulation. As shown in Figure 9(a), the PSSCH can occupy K subchannels in the frequency domain, and each subchannel can include N consecutive PRBs. K can be an integer greater than 0, and N can be an integer greater than 0.

[0073] As shown in FIG9( b ), when a time slot includes a PSFCH channel, the second to last and third to last symbols in the time slot can be used for PSFCH channel transmission, and a time domain symbol before the PSFCH channel can be used as a GP symbol.

[0074] PSSCH

[0075] In some sidelink communication systems (such as NR-V2X systems), PSSCH can be used to carry second-order sidelink control information (SCI). The second-order SCI can include SCI 2-A or SCI 2-B. The second-order SCI can use Polar coding. The second-order SCI can be fixedly modulated with QPSK. The data part of PSSCH can use low-density parity check (LDPC). The highest modulation order that the data part of PSSCH can support is 256QAM.

[0076] In some sideline communication systems (such as NR-V2X systems), PSSCH supports up to two stream transmissions and uses a unit precoding matrix to map data on two layers to two antenna ports. At most, only one TB can be sent in one PSSCH. However, unlike the transmission method of the PSSCH data part, when PSSCH adopts a dual-stream transmission method, the modulation symbols sent by the second-order SCI on the two streams are exactly the same. This design can ensure the reception performance of the second-order SCI in highly correlated channels.

[0077] In some sideline communication systems (such as NR-V2X systems), the maximum number of retransmissions of a PSSCH is 32 times. If there are PSFCH resources in the resource pool and the configuration period of the PSFCH resources is 2 or 4, the OFDM symbols available in the time slot where different transmissions of a PSSCH are located may change. Figure 10 is an example diagram of the change in the available OFDM symbols of the PSSCH in different time slots. As shown in Figure 10, due to the existence of PSFCH resources, the number of OFDM symbols available for the nth transmission and the n+1th transmission of the PSSCH is different. If the number of symbols transmitted by the PSSCH is calculated according to the actual number of OFDM symbols in a time slot The difference in the number of symbols available for PSSCH transmission in a time slot may cause Q′ SCI2 Different, and Q′ SCI2 The change of will lead to the change of the size of the TB carried by PSSCH, as described below. In order to ensure that the transmission block size (TBS) remains unchanged during multiple transmissions of PSSCH, The actual number of PSFCH symbols is not used. The number of resource elements (REs) occupied by the PSSCH demodulation reference signal (DMRS) and the number of REs occupied by the phase-tracking reference signal (PT-RS), which may change during the retransmission process, are not taken into account.

[0078] The code rate of the second-order SCI can be dynamically adjusted within a certain range, and the specific code rate used can be indicated by the first-order SCI. Therefore, even after the code rate changes, the receiver does not need to perform blind detection on the second-order SCI. Figure 11 shows an example of the time-frequency resources occupied by the second-order SCI in a time slot. As shown in Figure 11, the modulation symbols of the second-order SCI can be mapped starting from the symbol where the first PSSCH DMRS is located, using a frequency domain first and then a time domain mapping. In the OFDM symbol where the DMRS is located, the second-order SCI can be mapped to REs not occupied by the DMRS.

[0079] Within a resource pool, the data portion of the PSSCH can use multiple different modulation and coding scheme (MCS) tables. For example, one or more of the following tables can be used: the conventional 64QAM MCS table, the 256QAM MCS table, and the low spectrum efficiency 64QAM MCS table. In a transmission, the specific MCS table used for the data portion of the PSSCH can be indicated by the "MCS table indication" field in the first-order SCI. In order to control the PAPR, the PSSCH must be sent using continuous PRBs. Since the subchannel is the minimum frequency domain resource granularity of the PSSCH, the PSSCH must occupy continuous subchannels.

[0080] Sidelink TBS

[0081] PSSCH follows the TBS determination mechanism of the physical downlink shared channel (PDSCH) and the physical uplink shared channel (PUSCH), that is, the TBS can be determined based on the reference value of the number of REs used for PSSCH in the time slot where PSSCH is located, so that the actual code rate is as close to the target code rate as possible. It should be noted that the purpose of using the reference value of the number of REs instead of the actual number of REs is to ensure that the number of REs used to determine the TBS remains unchanged during the PSSCH retransmission process, so that the determined TBS size is the same. In order to achieve this goal, the reference value N of the number of REs occupied by PSSCH in the TBS determination process is used. RE It can be determined according to the following formula:

[0082] Among them, n PRB is the number of PRBs occupied by PSSCH, is the number of REs occupied by the first-order SCI (including the REs occupied by the DMRS of the PSCCH), is the number of REs occupied by the second-order SCI (as described above), N′ REIndicates the number of reference REs that can be used for PSSCH in a PRB. N' RE It can be determined by the following formula:

[0083] in, It can represent the number of subcarriers in a PRB, for example, Indicates the number of symbols available for sidelink in a time slot, which may not include the last GP symbol and the first symbol used for AGC. A reference value indicating the number of symbols occupied by the PSFCH, for example, or 3. The specific value can be indicated by the "PSFCH symbol number" field in the first-order SCI. It can represent the reference value of the number of REs occupied by PT-RS and channel state information-reference signal (CSI-RS), and can be configured by radio resource control (RRC) layer parameters. It can represent the average number of DMRS REs in a time slot, which is related to the DMRS pattern allowed in the resource pool. Table 1 shows the DMRS pattern allowed in the resource pool and The corresponding relationship.

[0084] Table 1

[0085] Sidelink DMRS

[0086] In some sideline communication systems (such as NR-V2X systems), the DMRS pattern of the PSCCH can be the same as that of the physical downlink control channel (PDCCH). That is, the DMRS can exist on each OFDM symbol of the PSCCH and can be located in the {#1, #5, #9} REs of a PRB in the frequency domain. Figure 12 is a schematic diagram of a DMRS pattern of the PSCCH. The DMRS sequence of the PSCCH is generated by the following formula:

[0087] Among them, the pseudo-random sequence c(m) can be obtained by Initialize. Wherein, l can represent the index of the OFDM symbol where the DMRS is located in the time slot, It can represent the index of the time slot where the DMRS is located in the system frame. It can represent the number of OFDM symbols in a time slot, N ID∈(0, 1, ..., 65535}, in a resource pool N ID The specific value is configured or pre-configured by the network.

[0088] Some sideline communication systems (such as NR-V2X systems) use multiple time-domain PSSCH DMRS patterns, which draws on the design of the Uu interface of the NR system. Within a resource pool, the number of available DMRS patterns can be related to the number of PSSCH symbols in the resource pool. For a specific number of PSSCH symbols (including the first AGC symbol) and PSCCH symbols, the available DMRS patterns and the position of each DMRS symbol within the pattern are shown in Table 2. Figure 13 shows the time-domain position of four DMRS symbols when the PSSCH has 14 symbols.

[0089] Table 2

[0090] If multiple time-domain DMRS patterns are configured within the resource pool, the transmitting terminal device selects the specific time-domain DMRS pattern to use and indicates this in the first-order SCI. This design allows high-speed terminal devices to select a high-density DMRS pattern, thereby ensuring channel estimation accuracy, while low-speed terminal devices can use a low-density DMRS pattern, thereby improving spectral efficiency.

[0091] The generation method of the PSSCH DMRS sequence is almost identical to that of the PSCCH DMRS sequence. The only difference is the initialization formula c(m) of the pseudo-random sequence. init middle, Among them, p i The ith CRC bit of the PSCCH that schedules the PSSCH. L may be the number of bits of the PSCCH CRC, for example, L=24.

[0092] In the NR communication system, two frequency domain DMRS patterns are supported in PDSCH and PUSCH, namely DMRS frequency domain type 1 and DMRS frequency domain type 2. For each frequency domain type, there are two different types: single DMRS symbol and double DMRS symbol. Single-symbol DMRS frequency domain type 1 supports 4 DMRS ports, and single-symbol DMRS frequency domain type 2 can support 6 DMRS ports. In the case of double DMRS symbols, the number of supported ports is doubled. However, in sideline communication systems (such as NR-V2X), since PSSCH only needs to support two DMRS ports at most, only single-symbol DMRS frequency domain type 1 can be supported. Figure 14 is an example diagram of a single-symbol DMRS frequency domain type 1.

[0093] Sidelink CSI-RS

[0094] The sidelink communication system can support sidelink CSI-RS (SL CSI-RS) to better support unicast communication. SL CSI-RS can be transmitted when the following three conditions are met: the terminal device transmits the corresponding PSSCH (that is, the terminal device cannot only transmit SL CSI-RS); higher-layer signaling activates SL CSI-RS reporting; when higher-layer signaling activates SL CSI-RS reporting, the corresponding bit in the second-order SCI sent by the terminal device triggers SL CSI-RS reporting.

[0095] The maximum number of ports supported by SL CSI-RS is 2. Two ports are SL CSI-RSs from different ports, multiplexed via code division on two adjacent REs in the same OFDM symbol. The number of SL CSI-RSs per port within a PRB is 1, meaning the density is 1. Therefore, an SL CSI-RS appears in at most one OFDM symbol within a PRB. The specific location of this OFDM symbol can be determined by the transmitting terminal device. To avoid impacting the resource mapping of the PSCCH and second-order SCI, the SL CSI-RS cannot be located in the same OFDM symbol as the PSCCH and second-order SCI. Because the channel estimation accuracy of the OFDM symbol where the PSSCH DMRS resides is higher, and the SL CSI-RSs of two ports occupy two consecutive REs in the frequency domain, the SL CSI-RS cannot be transmitted in the same OFDM symbol as the PSSCH DMRS. The OFDM symbol location of the SL CSI-RS is indicated by the sl-CSI-RS-FirstSymbol parameter in the PC5RRC.

[0096] The position of the first RE occupied by SL CSI-RS in a PRB can be indicated by the sl-CSI-RS-FreqAllocation parameter in PC5RRC. If SL CSI-RS is one port, the parameter can be a bitmap with a length of 12, corresponding to 12 REs in one PRB. If SL CSI-RS is two ports, the parameter is a bitmap with a length of 6. In this case, SL CSI-RS can occupy two REs, 2f(1) and 2f(1)+1. Among them, f(1) can represent the index of the bit with a value of 1 in the above bitmap. The frequency domain position of SL CSI-RS can also be determined by the transmitting terminal device. The determined frequency domain position of SL CSI-RS cannot conflict with PT-RS. Figure 15 is an example diagram of the time-frequency position of SL CSI-RS. In FIG15 , the number of SL CSI-RS ports is 2, the sl-CSI-RS-FirstSymbol is 8, and the sl-CSI-RS-FreqAllocation is [b5, b4, b3, b2, b1, b0] = [0, 0, 0, 1, 0, 0].

[0097] Unlicensed spectrum communications

[0098] Unlicensed spectrum is spectrum designated by countries and regions for use by radio equipment. This spectrum is generally considered shared spectrum, meaning that as long as communications equipment meets national or regional regulatory requirements for the spectrum, it can use it without having to apply for exclusive spectrum authorization from the national or regional spectrum management agency. Unlicensed spectrum may also be referred to as shared spectrum, unlicensed spectrum, unlicensed frequency band, or unlicensed frequency band.

[0099] In LTE systems, unlicensed spectrum has been used as a supplementary frequency band to licensed spectrum for cellular networks. NR systems can achieve seamless cellular network coverage, high spectral efficiency, high peak rates, and high reliability. NR systems can also use unlicensed spectrum as part of 5G cellular network technology to provide services to users. The 3GPP Release 16 standard discusses NR systems using unlicensed spectrum, referred to as NR-unlicensed (NR-U) systems.

[0100] The NR-U system supports two networking modes: licensed spectrum assisted access and unlicensed spectrum independent access. Licensed spectrum assisted access requires the use of licensed spectrum to access the network, and unlicensed spectrum is used as a secondary carrier. Unlicensed spectrum independent access can independently network through unlicensed spectrum, and terminal devices can directly access the network through unlicensed spectrum. The range of unlicensed spectrum used by the NR-U system introduced in 3GPP R16 is concentrated in the 5GHz and 6GHz frequency bands. For example, in the United States, the range of unlicensed spectrum is 5925–7125MHz; in Europe, the range of unlicensed spectrum is 5925–6425MHz. In the R16 standard, band 46 (5150MHz-5925MHz) is newly defined for use as unlicensed spectrum.

[0101] The use of unlicensed spectrum needs to meet the specific regulatory requirements of each country and region. For example, communication equipment can use unlicensed spectrum to achieve channel access on the unlicensed spectrum through channel monitoring to avoid conflicts with other communication equipment or other communication systems (such as WiFi systems). As an implementation method, communication equipment can use unlicensed spectrum in accordance with the principle of "listen-before-talk" (LBT). Therefore, for NR-U, NR technology needs to be enhanced accordingly to adapt to the regulatory requirements of unlicensed frequency bands, while efficiently utilizing unlicensed spectrum to provide services. In the 3GPP R16 standard, the standardization of NR-U technology in the following aspects is mainly completed: channel monitoring process; initial access process; control channel design; HARQ and scheduling; scheduling-free authorized transmission, etc.

[0102] LBT

[0103] The LBT principle may include: before a communication device uses a channel on an unlicensed spectrum to send a signal, it must first perform LBT. In the case of a successful LBT, the result of the channel monitoring is that the channel is idle. Only when the channel is idle can the communication device send a signal through the channel. If the channel monitoring result of the communication device on the channel is that the channel is busy or LBT fails, then the communication device cannot send a signal through the channel. In addition, in order to ensure fairness in the use of spectrum resources of the shared spectrum, if a communication device succeeds in LBT on a channel on an unlicensed spectrum, the duration for which the communication device can use the channel for communication transmission cannot exceed a certain duration. By limiting the maximum duration for communication after a successful LBT, this mechanism can give different communication devices the opportunity to access the shared channel, thereby allowing different communication systems to coexist in a friendly manner on the shared spectrum.

[0104] Signal transmission in unlicensed spectrum involves concepts related to channel occupancy, such as channel occupancy time (COT), maximum channel occupancy time (MCOT), the COT of network devices (such as base stations), and the COT of terminal devices.

[0105] MCOT refers to the maximum duration a communication device is allowed to transmit signals using unlicensed spectrum channels if LBT is successful. It should be understood that MCOT refers to the duration of signal transmission. Different communication devices with different channel access priorities may have different MCOT values. For example, the maximum MCOT value can be set to 10ms.

[0106] FIG16 is an example diagram showing a channel occupancy time obtained by a communication device after successful LBT on a channel of an unlicensed spectrum, and signal transmission using resources within the channel occupancy time.

[0107] Although channel sensing is not a global regulatory requirement, it can provide interference avoidance and coexistence benefits for communication systems on shared spectrum. Therefore, during the design of NR systems on unlicensed spectrum, channel sensing is a feature that communication equipment in the system must support.

[0108] Unlicensed spectrum channel access method

[0109] Some communication systems (such as the NR-U system) introduce a channel access method using LBT.

[0110] From a system networking perspective, LBT can be implemented in two ways: load-based equipment (LBE) LBT, also known as dynamic channel monitoring or dynamic channel occupancy; and frame-based equipment (FBE) LBT, also known as semi-static channel monitoring or semi-static channel occupancy. The principle of dynamic channel monitoring LBT is that a communication device performs LBT on a carrier in unlicensed spectrum upon service arrival and begins transmitting signals on that carrier after successful LBT.

[0111] The LBT mode of dynamic channel monitoring may include a Type 1 (Type 1) channel access mode and a Type 2 (Type 2) channel access mode.

[0112] The following describes in detail the Type 1 channel access method and the Type 2 channel access method using a network device as an example. It is understandable that the channel monitoring process of other communication devices such as terminal devices using the Type 1 channel access method or the Type 2 channel access method is similar.

[0113] Type 1 channel access method can also be called multi-slot channel detection with random backoff based on contention window size adjustment. In type 1 channel access method, the corresponding channel access priority class (CAPC) p can be selected according to the priority of the service to be transmitted. The communication device can initiate channel occupancy of length Tmcot according to the channel access priority p. If the network device uses type 1 channel access method, then the network device can not only send its own data during the channel occupancy period, but also share the COT with the terminal device. The so-called sharing of COT with the terminal device means: allowing the terminal device to send data within the time length corresponding to the COT (that is, the COT obtained by the network device through channel access). Accordingly, if the terminal device uses type 1 channel access method, then the terminal device can not only send its own data during the channel occupancy period, but also share the COT with the network device.

[0114] Table 3 shows the channel access priority and its corresponding parameters when the terminal device performs type 1 channel access.

[0115] Table 3

[0116] The default channel access mode on the network device side is type 1 channel access mode. The channel access parameters corresponding to the channel access priority p are shown in Table 3. In Table 3, m p It can refer to the number of fallback slots corresponding to the channel access priority p, CW p It can refer to the contention window (CW) size corresponding to the channel access priority p. min,p It can refer to the CW corresponding to the channel access priority p p Minimum value, CW max,p It can refer to the CW corresponding to the channel access priority p p The maximum value, T mcot,p It refers to the maximum channel occupancy time corresponding to the channel access priority p.

[0117] Type 2 channel access is also known as a channel access method based on fixed-length channel monitoring time slots. Type 2 channel access methods include Type 2A, Type 2B, and Type 2C. When resources within a COT are shared with other communication devices, these other devices can use Type 2 channel access.

[0118] In Type 2A channel access, a communication device can use a single-slot detection of the channel every 25 us. This means that the communication device can begin channel detection 25 us before starting to send data. This 25 us channel detection can include one 16 us channel detection and one 9 us channel detection. If both detection results indicate that the channel is idle, the channel is considered idle and channel access can be performed.

[0119] In the Type 2B channel access method, the communication device can use a 16-us single-slot channel detection process. During the channel detection process, if the communication device detects that the channel is idle for more than 4 us within the last 9 us, it can be considered that the channel is idle.

[0120] In the Type 2C channel access method, communication devices can transmit data directly over the channel without performing channel detection. In the Type 2C channel access method, the time difference between the current transmission and the previous transmission is less than or equal to 16us. In other words, if the time difference between two transmissions is less than or equal to 16us, they can be considered to be the same transmission and channel detection is not required. It should be noted that in the Type 2C channel access method, the transmission time of communication devices is limited and generally cannot exceed 584us.

[0121] A special case that needs to be explained is that when the network device initiates channel occupancy to transmit the synchronization signal block (synchronizing signal / PBCH block, SS / PBCH block) within the discovery reference signal (DRS) window and the DRS window does not include unicast data transmission of the terminal device, if the length of the DRS window does not exceed 1ms and the duty cycle of the DRS window transmission does not exceed 1 / 20, then the network device can use type 2A channel access to initiate channel occupancy.

[0122] Channel access parameter indication

[0123] In some communication systems based on unlicensed spectrum (such as NR-U systems), when a terminal device is scheduled to transmit PUSCH or physical uplink control channel (PUCCH), the network device can indicate the channel access method corresponding to the PUSCH or PUCCH by carrying downlink control information (DCI) of uplink grant (UL grant) or downlink grant (DL grant). In addition, since some channel access methods need to meet the gap requirements of 16μs or 25μs, the terminal device can ensure the gap size between two transmissions by transmitting a cyclic prefix extension (CPE). Accordingly, the network device can indicate the CPE length of the first symbol of the uplink transmission of the terminal device.

[0124] When specifically indicating, the network device can explicitly indicate channel access parameters such as CPE length, channel access mode, or channel access priority to the terminal device through joint coding. The following describes the characteristics of the channel access parameter indication methods introduced in different DCI formats.

[0125] 1. Fallback uplink grant for scheduling PUSCH transmission (DCI format 0_0)

[0126] The standard predefines a set of channel access mode and CPE length joint indications, as shown in Table 4. The fallback uplink grant includes 2-bit LBT indication information. This 2-bit LBT indication information is used to indicate the jointly coded channel access mode and CPE length from the set shown in Table 4. This channel access mode and CPE length are used for PUSCH transmission. If the channel access mode is Type 1 channel access, the terminal device can select the CAPC based on the service priority.

[0127] Table 4

[0128] In Table 4, the value of C1 is specified by the protocol. When the subcarrier spacing is 15 kHz and 30 kHz, C1 = 1; when the subcarrier spacing is 60 kHz, C1 = 2. The values ​​of C2 and C3 are configured by higher-layer parameters. When the subcarrier spacing is 15 kHz and 30 kHz, the values ​​of C2 and C3 range from 1 to 28; when the subcarrier spacing is 60 kHz, the values ​​of C2 and C3 range from 2 to 28.

[0129] 2. Fallback downlink grant for scheduling PDSCH transmission (DCI format 1_0)

[0130] The standard presets a set of joint indications of channel access mode and CPE length, and the set is shown in Table 4. The fallback downlink grant includes 2-bit LBT indication information, and the 2-bit LBT indication information is used to indicate the jointly coded channel access mode and CPE length from the set shown in Table 4. The channel access mode and CPE length are used for PUCCH transmission, wherein the PUCCH can carry acknowledgment (ACK) or negative acknowledgment (NACK) information corresponding to the PDSCH. If the channel access mode is type 1 channel access, the terminal device can determine that the CAPC used to transmit the PUCCH is 1.

[0131] 3. Non-fallback uplink grant for scheduling PUSCH transmission (DCI format 0_1)

[0132] The high layer configures the LBT parameter indication set. The LBT parameter indication set includes at least one joint coding. The joint coding is used to indicate the channel access method, CPE length and CAPC. The non-fallback uplink authorization includes LBT indication information. The LBT indication information is used to indicate the jointly coded channel access method, CPE length and CAPC from the above-mentioned LBT parameter indication set. The channel access method, CPE length and CAPC are used for PUSCH transmission. If the indicated channel access method is type 2 channel access, the CAPC indicated at the same time is the CAPC used by the network device when obtaining the COT. In addition, the LBT indication information includes a maximum of 6 bits.

[0133] 4. Non-fallback downlink grant for scheduling PDSCH transmission (DCI format 1_1):

[0134] The high layer configures the LBT parameter indication set. The LBT parameter indication set includes at least one joint coding. The joint coding is used to indicate the channel access method and CPE length. The non-fallback downlink authorization includes LBT indication information. The LBT indication information is used to indicate the channel access method and CPE length of the joint coding from the above-mentioned LBT parameter indication set. The channel access method and CPE length are used for PUCCH transmission. Among them, the PUCCH can carry the ACK or NACK information corresponding to the PDSCH. If the channel access method is type 1 channel access, the terminal device can determine that the CAPC used to transmit the PUCCH is 1. In addition, the LBT indication information includes a maximum of 4 bits.

[0135] In addition to the above explicit indications, the network device can also implicitly indicate the channel access method within the COT. For example, when the terminal device receives an uplink authorization or downlink authorization sent by the base station indicating that the channel access type corresponding to the PUSCH or PUCCH is type 1 channel access, if the terminal device can determine that the PUSCH or PUCCH belongs to the COT of the network device, for example, the terminal device receives a DCI format 2_0 sent by the network device, and determines that the PUSCH or PUCCH belongs to the COT of the network device based on the DCI format 2_0, then the terminal device can update the channel access type corresponding to the PUSCH or PUCCH to type 2A channel access instead of using type 1 channel access.

[0136] In sidelink communications over unlicensed spectrum, even after successful listen-before-talk (LBT) calls, sidelink communication may still be unavailable. For example, in some sidelink communications, resources for sidelink communication begin at the time slot boundary, meaning that sidelink signals or channels can only be transmitted from that time slot boundary. Therefore, during the period between successful LBT and the time slot boundary, other communication devices in different systems may preempt the channel, preventing the terminal device from conducting sidelink communication at the time slot boundary.

[0137] Figure 17 is a schematic flow chart of a communication method provided in an embodiment of the present application to solve the above problem. The method shown in Figure 17 can be implemented by a terminal device.

[0138] The method shown in Figure 17 may include step S1710. Step S1710: Before communicating through the first sidelink resource, the terminal device may send a first CPE.

[0139] The first sideline resource can be a resource used by a terminal device for sideline communication. That is, the terminal device can send a sideline signal and / or a sideline channel based on the first sideline resource. Based on the first sideline resource, the terminal device can send sideline data to another terminal device. That is, the terminal device can be the sender of the sidelink communication. Therefore, the first sideline resource can also be called the first sidelink transmission resource. In some embodiments, the resource for sideline communication needs to start from the boundary of the time slot. Therefore, the first sideline resource can start from the beginning of a time slot.

[0140] This application does not limit the mode for determining the first sideline resource. For example, the first sideline resource can be scheduled using the first mode. In other words, the first sideline resource can be allocated by the network device. Alternatively, the first sideline resource can be determined using the second mode. In other words, the first sideline resource can be autonomously selected by the terminal device from a resource pool.

[0141] In addition, it should be noted that the first sidelink resource may belong to unlicensed spectrum. Therefore, before using the first sidelink resource for sidelink communication, the terminal device may perform LBT. This application does not limit how the terminal device performs LBT. For example, the terminal device may perform LBT using type 1 or type 2 channel access.

[0142] In some embodiments, the first sidelink resource may include one or more resource units. A resource unit may correspond to a sidelink time slot in the time domain. A resource unit may correspond to one or more RBs in the frequency domain. In some embodiments, a resource unit may also be referred to as a sidelink transmission resource. The CPE preceding one or more resource units may be a first CPE, i.e., the first information may indicate the length of the CPE preceding one or more resource units. Alternatively, a CPE may exist before any one of the one or more resource units, and each CPE may be a first CPE, i.e., the first information may indicate the length of the CPE preceding any one of the one or more resource units.

[0143] The first CPE can be sent before the first sideline resource. In other words, the terminal device can continue to send the first CPE before the first sideline resource arrives. The interval between the end time of sending the first CPE and the start time of the first sideline resource can be very short or 0. The interval can satisfy: within the interval, the corresponding channel is difficult to be preempted by other communication devices. As mentioned above, the first sideline resource can start from the beginning time of a time slot. Therefore, the first CPE can be sent before the time slot for sending the sideline information and / or the sideline channel. In addition, the first CPE can be sent after the LBT is successful. That is to say, the first CPE can continue to occupy the channel where the terminal device successfully LBTs to avoid other communication devices from preempting the channel.

[0144] Before using the first sideline communication resource for sideline communication, the terminal device may occupy the channel through the first CPE until the terminal device can use the first sideline resource for sideline communication. It is understood that the first CPE can prevent other communication devices from preempting the channel that has successfully established LBT, thereby allowing the terminal device to normally use the first sideline resource for sideline communication.

[0145] In some embodiments, during the process of sending the first CPE, the terminal device can still perform LBT to confirm that the channel can be used for sideline communication. For example, before sending the first CPE, the terminal device can perform long LBT, and during the process of sending the first CPE, the terminal device can perform short LBT.

[0146] This application also proposes a technical solution for determining the length of the first CPE. For ease of description, the length of the first CPE is referred to as the first length below.

[0147] In some embodiments, the first length may be determined based on first information indicated by the network device. As shown in FIG17 , the method shown in FIG17 may also be implemented by the network device. The method shown in FIG17 may further include step S1702.

[0148] In step S1702, the network device may send first information, and correspondingly, the terminal device may receive the first information.

[0149] The first information may be used to indicate the first length. This application does not limit the manner in which the first information indicates the first length. For example, the first information may directly indicate the first length or indirectly indicate the first length.

[0150] As an implementation manner, the first sidelink resource may belong to a first resource pool, and the first resource pool may support one or more configuration lengths. The configuration length may be used to indicate the CPE length that the first resource pool can support. The first information may be used to indicate that the first length is one of the one or more configuration lengths. As an implementation manner, the first information may indicate a first index, and the first index may correspond to one of the one or more configuration lengths. That is, the first information may indicate that the first length is the length corresponding to the first index. As another implementation manner, the first information may include the first length. The terminal device may obtain the first length by parsing the first information.

[0151] In some embodiments, when scheduling sidelink resources using a first mode, the first length can be determined by first information indicated by the network device. It will be appreciated that when the network device allocates resources using the first mode, the network device can uniformly allocate and schedule sidelink resources. In this case, the network device can flexibly indicate different CPE lengths, thereby avoiding mutual obstruction between different terminal devices. The mutual obstruction between terminals is described below with reference to Figure 19 and will not be further elaborated here.

[0152] It should be noted that one or more configuration lengths supported by the first resource pool can be configured by the network device. For example, the network device can configure one or more configuration lengths for the first resource pool through high-level signaling. The high-level signaling can be, for example, RRC signaling. For example, when configuring the first sidelink resource pool, the configuration parameter set can include a high-level parameter, which includes the CPE length value (i.e., the configuration length) that the configured first resource pool can support. For example, the high-level parameter can be represented by CP-extension-SL, and CP-extension-SL can be {16, 25, 34, 43, 52, 61}. The numerical unit of CP-extension-SL is microseconds. In other words, the first length can be one of {16, 25, 34, 43, 52, 61}.

[0153] The first information may be carried in information or a message indicating the first sidelink resource. That is, the first information may be carried in information or a message used for resource allocation or scheduling. The information or message used for resource allocation or scheduling may be, for example, DCI / PDCCH or higher-layer signaling.

[0154] In some embodiments, the first information may be carried in the first DCI or a PDCCH corresponding to the first DCI.

[0155] As an implementation, the first DCI may be used to dynamically schedule the first sidelink resource. That is, in sidelink resource allocation mode 1, if the network device allocates the first sidelink resource through a dynamically scheduled resource allocation method, the first DCI may carry information indicating the first length.

[0156] As another implementation, the first DCI may be used to activate the first sidelink resource allocated through configured grant (CG) type 2. In other words, in the case of sidelink resource allocation mode 1, if the network device allocates the first sidelink resource through configured grant type 2 resource allocation, the first DCI for activating configured grant type 2 may carry information indicating the first length.

[0157] The lengths of the CPE indicated by different DCIs may be the same or different. For example, the second DCI may include second information, which may be used to indicate a second length. The second length may be the length of the CPE sent before communication via the second sidelink resource. The first length and the second length may be the same or different. This description is made below using the scenario shown in Figure 18 as an example.

[0158] In Figure 18 , the first DCI is represented by DCI1, and the second DCI is represented by DCI2. The first sidelink resource indicated by the first DCI for sidelink transmission includes time slot 1. The first DCI also indicates the first length of the first CPE transmitted before time slot 1. As shown in Figure 18 , the first length corresponds to the length of the bolded CPE2. Therefore, the terminal device determines the starting point 1 for sidelink transmission, i.e., the terminal device can start transmitting the first CPE at starting point 1. The second sidelink resource indicated by the second DCI for sidelink transmission includes time slot n. n can be an integer greater than 1. The second DCI also indicates the length of the second CPE used before time slot n. The length of the second CPE can be the same as or different from the length of the first CPE. Figure 18 uses the example of the case where the length of the second CPE is different from the length of the first CPE. As shown in Figure 18 , the length of the second CPE is the length corresponding to the bolded CPE3. Therefore, the terminal device can determine the starting point 2 for sidelink transmission, i.e., the terminal device can start transmitting the second CPE at starting point 2.

[0159] It should be noted that the first DCI and the second DCI may indicate the same TB or different TBs. When indicating the same TB, the lengths of the CPE indicated by the first DCI and the second DCI may be the same or different, that is, the first length and the second length may be the same or different. When indicating different TBs, the lengths of the CPE indicated by the first DCI and the second DCI may be the same or different, that is, the first length and the second length may be the same or different. The following uses three cases as examples for illustration.

[0160] In case 1, the K resource units indicated by the first DCI or the PDCCH corresponding to the first DCI (hereinafter referred to as PDCCH / DCI#1) are used to transmit the first TB (hereinafter referred to as TB#1). K may be an integer greater than or equal to 1. PDCCH / DCI#1 may be used to indicate the CPE length preceding each of the K resource units. In case 2, the CPE lengths preceding the K sidelink resources indicated by PDCCH / DCI#1 may be the same.

[0161] In the second case, the K resource units indicated by PDCCH / DCI#1 are used to transmit TB#1, and the K' resource units indicated by the second DCI or the PDCCH corresponding to the second DCI (hereinafter referred to as PDCCH / DCI#2) are used to transmit TB#1. K' can be an integer different from K, and the value of K' can be greater than or equal to 1. The first length indicated by PDCCH / DCI#1 and the second length indicated by PDCCH / DCI#2 can be the same or different. The scenarios corresponding to the second case may include, for example: PDCCH / DCI#1 indicates the resources for the new transmission and several retransmissions of TB#1; when the new transmission and retransmission of PDCCH / DCI#1 fail, PDCCH / DCI#2 can indicate the resources for the subsequent retransmission of TB#1.

[0162] In case three, the K resource units indicated by PDCCH / DCI#1 are used to transmit TB#1, and the K' resource units indicated by PDCCH / DCI#2 are used to transmit the second TB (hereinafter referred to as TB#2). The first length indicated by PDCCH / DCI#1 and the second length indicated by DCI#2 can be the same or different. In other words, the CPE lengths of different TBs indicated by DCI can be the same or different.

[0163] As described above, the first information may be carried in information or a message indicating the first sidelink resource. In some embodiments, the first information may be configured or indicated via a configuration authorization. For example, the first information may be carried in higher-layer signaling, which may be used to configure a sidelink configuration authorization. In other words, the higher-layer signaling for configuring a sidelink configuration authorization may include the first information.

[0164] Different terminal devices can use the same time domain resources in the same resource pool and utilize this same time domain resource via FDM. If the CPE lengths of different terminal devices differ, this may result in one or more of the terminal devices' CPEs being blocked from transmitting. Even if the time domain resource is available, data cannot be transmitted using this time domain resource. The following scenario is specifically described using Figure 19. As shown in Figure 19, terminal device 1 (represented by UE1 in Figure 19) and terminal device 2 (represented by UE2 in Figure 19) can both use time slot 1 in the resource pool for sideline communication. Terminal devices in the resource pool can transmit CPEs of any length from CPE1 to CPE4. If terminal device 1 uses CPE1 and terminal device 2 uses CPE2, terminal device 1 can complete LBT and successfully access the channel and begin transmitting CPE1 from starting point 1. However, since terminal device 2 uses CPE2, terminal device 2 may only be able to transmit CPE2 from starting point 2. Therefore, if Terminal 2 is still performing LBT between starting points 1 and 2, it will be blocked by CPE1's transmission from Terminal 1, causing Terminal 2 to fail to monitor the channel and be unable to send data. However, in reality, Terminal 1 is not performing sideline communication between starting points 1 and 2, and Terminal 2 can send data in timeslot 1 using FDM.

[0165] In response to the above problems, the present application proposes that, for terminal devices within the same resource pool, the length of the CPE sent by the terminal devices is the same. For example, the first sidelink resource may belong to the second resource pool. The second resource pool may support a first configuration length. The first length may be determined based on the first configuration length. Terminal devices that use resources in the second resource pool for communication may all determine the length of the CPE based on the first configuration length. In some embodiments, the second resource pool may only support the first configuration length, that is, the second resource pool may only support one type of CPE length, so that the CPE lengths determined by the terminal devices using the second resource pool may be the same. In the case where the second resource pool only supports the first configuration length, the first configuration length may be used as the default CPE length.

[0166] In some embodiments, the first length may be equal to the first configured length. That is, the length of CPE messages sent by terminal devices using resources in the second resource pool for communication may be the first configured length.

[0167] The technical solution proposed in this application that the length of CPE sent by terminal devices in the same resource pool is the same can make the starting point of CPE sent by different terminal devices the same. As shown in Figure 20, the resource pool uses the CPE length corresponding to CPE2 as the first configuration length. All terminal devices using the second resource pool can use the length corresponding to CPE2 to send CPE before sending side signals or channels. Terminal device 1 and terminal device 2 can send CPE of the same length in the same time slot (for example, time slot 0), and the starting point of sending CPE is the same. Therefore, terminal device 1 and terminal device 2 can both successfully LBT before sending CPE, so that both start sending CPE at starting point 1, and then start side communication in the same time slot (for example, time slot 1). In other words, this technical solution can avoid the problem of a terminal device being unable to perform side communication due to obstruction between terminal devices.

[0168] It should be noted that when FDM exists between terminal devices, the technical solution proposed in this application can be used, and when time division multiplexing (TDM) exists between terminal devices, the technical solution proposed in this application can also be used. That is to say, in the same time slot of the same resource pool, when FDM exists between different terminal devices, CPEs of the same length can be sent. In different time slots of the same resource pool, when TDM exists between different terminal devices, different terminal devices can send CPEs of the same length. Continuing with Figure 20 as an example, the length of the CPE sent by terminal device 3 (represented by UE3 in Figure 20) in time slot n-1 is the same as the length of the CPE sent by terminal device 1 in time slot 0.

[0169] It should be noted that the first configured length of the second resource pool described above may be configured by the network device or preconfigured. For example, the network device may indicate the first configured length via first information, thereby indicating the first length. In other words, the network device may indirectly indicate the first length by indicating the first configured length.

[0170] As an implementation, the network device may configure or indicate the first configuration length via higher-layer signaling. For example, when the network device configures the second resource pool, the configuration parameter set may include a higher-layer parameter. This higher-layer parameter may include a CPE length value supported by the configured resource pool. The higher-layer parameter may be represented by a CP-extension-SL, which may satisfy: CP-extension-SL = {34}. The higher-layer parameter may be expressed in microseconds.

[0171] In some embodiments, when the network device reconfigures the second resource pool, the first configuration length may be changed, or the first configuration length may remain unchanged.

[0172] This application also provides a technical solution for determining the CPE length supported by a resource pool based on the relationship between different resource pools. For example, the relationship between different resource pools may include: belonging to different resource block sets (RB sets), or some or all resources belonging to the same RB set. This is illustrated below with reference to Figure 21.

[0173] In some embodiments, different resource pools (e.g., the second resource pool and the third resource pool) may belong to different RB sets. In other words, the second resource pool and the third resource pool contain different RB sets. In other words, the second resource pool and the third resource pool contain no overlap in RB sets. Figure 21(a) is an example diagram showing that the second resource pool and the third resource pool belong to different RB sets. As shown in Figure 21(a), the second resource pool (represented by resource pool 2 in Figure 21) includes RB set 0 and RB set 1. The third resource pool (represented by resource pool 3 in Figure 21) includes RB set 2 and RB set 3.

[0174] In some embodiments, some or all resources in different resource pools (e.g., the second resource pool and the third resource pool) may belong to the same RB set. For example, the RB set contained in the second resource pool and the RB set contained in the third resource pool are identical. Alternatively, some or all resources in the second resource pool and some or all resources in the third resource pool may belong to the same one or more RB sets. For example, some RBs in an RB set may belong to the second resource pool, while another portion of the RBs in the RB set may belong to the third resource pool.

[0175] It should be noted that, generally speaking, it is unlikely that a certain RB or a certain part of RBs belong to both the second resource pool and the third resource pool.

[0176] It should be noted that the resources in the same RB set of the second resource pool or the third resource pool can be continuous or discontinuous in the frequency domain. Discontinuous frequency domain resources can be achieved by allocating frequency domain resources in a comb-shaped resource block (IRB) manner.

[0177] Figures 21(b) and 21(c) illustrate the case where some resources in the second resource pool and some resources in the third resource pool belong to the same RB set. As shown in Figure 21(b), the second resource pool includes all resources in RB set 0 and some contiguous resources in RB set 1; the third resource pool includes some contiguous resources in RB set 1, all resources in RB set 2, and all resources in RB set 3. As shown in Figure 21(c), the second resource pool includes all resources in RB set 0 and some discontiguous resources in RB set 1; the third resource pool includes some discontiguous resources in RB set 1, all resources in RB set 2, and all resources in RB set 3.

[0178] It can be seen from this that the technical solution proposed in this application can support the situation where different resources in an RB set belong to different resource pools, thereby improving resource utilization efficiency.

[0179] It should be noted that the second resource pool and the third resource pool can share resources in the same RB set through FDM. That is, some or all resources in the second resource pool and some or all resources in the third resource pool can be multiplexed in the same RB set through FDM.

[0180] When the second resource pool and the third resource pool belong to different RB sets, the CPE length supported by the second resource pool and the CPE length supported by the third resource pool may be the same or different. For example, the third resource pool may support a second configuration length, and the length of the CPE before communication through the sidelink resources in the third resource pool may be a third length, which may be determined based on the second configuration length. The second configuration length may be the same as or different from the first configuration length. For the scenario shown in Figure 21(a), the CPE lengths supported by the second resource pool and the third resource pool may be the same or different.

[0181] In the case where some or all of the resources in the second resource pool and some or all of the resources in the third resource pool belong to the same RB set, the CPE length supported by the second resource pool and the CPE length supported by the third resource pool may be the same. In other words, the second configuration length may be the same as the first configuration length. For the scenario shown in Figure 21(b) or Figure 21(c), the lengths of the CPEs supported by the second resource pool and the third resource pool may be the same. It is understandable that when a terminal device uses the resources in the same RB set through the second resource pool, another terminal device may use the resources in the same RB set through the third resource pool. If the lengths of the CPEs sent by the two terminal devices are different, one of the terminal devices may also have the blocking situation described above, resulting in side communication abnormalities. Therefore, the present application can avoid blocking between terminal devices.

[0182] It should be noted that regardless of whether some or all of the resources in the second resource pool and some or all of the resources in the third resource pool belong to the same RB set, FDM can exist in both the second and third resource pools. For example, in the three scenarios shown in Figures 21(a), 21(b), and 21(c), FDM exists in both the second and third resource pools.

[0183] It should be noted that the second resource pool can be used for resource allocation in either the first or second mode. The third resource pool can be used for resource allocation in either the first or second mode. That is, in either the second or third resource pool, the terminal device can select resources on its own, or the network device can select resources for the terminal device. For example, the second resource pool can be used for resource allocation in either the first or second mode, and the third resource pool can be used for resource allocation in either the second or second mode. Alternatively, both the second and third resource pools can be used for resource allocation in either the second or second mode.

[0184] It should be noted that the resource pool can be a sidelink resource pool configured by the network device, or a sidelink pre-configured resource pool. For example, the second resource pool can be configured by the network device, or can be pre-configured.

[0185] The first length or the first configured length may be determined based on one or more of the following information: whether the terminal device is a terminal device initiating a COT, whether the terminal device is a terminal device sharing a COT, and the subcarrier spacing. In the presence of a sidelink COT, the terminal device initiating the COT may obtain the COT through a channel access process and share the COT with the terminal devices sharing the COT, thereby enabling the shared COT terminal devices to transmit data within the COT.

[0186] As an implementation method, if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30kHz, the first length or the first configuration length may satisfy: greater than 0 and less than or equal to 1 OFDM symbol length. If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30kHz, the first length or the first configuration length may satisfy: greater than 0 and less than or equal to 2 OFDM symbol lengths. The subcarrier spacing may, for example, include at least one of 15kHz, 30kHz, and 60kHz. For example, if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is 15kHz, the value range of the first configuration length of the second resource pool (i.e., the default CPE length of the second resource pool) may be greater than 0 and less than 1 OFDM symbol. Alternatively, if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is 30kHz or 60kHz, the value range of the first configuration length of the second resource pool (i.e., the default CPE length of the second resource pool) may be greater than 0 and less than 2 OFDM symbols.

[0187] As another implementation, if the terminal device is a terminal device that shares a COT, the first length or the first configured length satisfies: greater than 0 and less than or equal to the length of one OFDM symbol. For example, if the terminal device is a terminal device that shares a COT, when the subcarrier spacing is 15 kHz, 30 kHz, or 60 kHz, the value range of the first configured length of the second resource pool (i.e., the default CPE length of the second resource pool) can be greater than 0 and less than 1 OFDM symbol.

[0188] In the case where there may be mutual obstruction between terminal devices, the present application proposes that the length of the CPE sent by the terminal device can be different. The length of the CPE sent by the terminal device can be determined based on the first condition. In other words, the first length can be determined based on the first condition.

[0189] The first condition may be related to one or more of the following information: the priority of the first CPE, the information that the terminal device initiates the COT, and the information that the terminal device occupies the COT.

[0190] The priority of the first CPE may be represented by information that can reflect the priority of the first CPE. For example, the priority of the first CPE may include: the priority indicated by the physical layer (layer 1) and the CAPC corresponding to the first CPE.

[0191] The information about whether the terminal device initiates COT may include whether the terminal device initiates COT. For example, when the terminal device initiates COT, the length of the corresponding CPE may be determined.

[0192] The information about the terminal device occupying the COT may include whether the terminal device occupies the COT. For example, when the terminal device occupies the COT initiated by other communication devices, the length of the corresponding CPE may be determined.

[0193] By setting the length of the corresponding CPE according to the first condition, some terminal devices can be prevented from being blocked when blocking is unavoidable. For example, the length of the CPE sent by a terminal device with a higher priority can be determined according to the first condition to avoid blocking of the terminal device with a higher priority.

[0194] As an embodiment, a sidelink resource pool, such as the second resource pool, can support N configuration lengths, that is, it can support N CPE lengths. N can be greater than 1. For all terminal devices using the second resource pool, the length of the CPE sent before sending the sidelink information or the time slot where the channel is located can be different. The length of the CPE sent can be selected from N configuration lengths. The selection condition can meet the first condition mentioned above. For example, the terminal device can select a configuration length a as the CPE length based on the priority indicated by layer 1. Alternatively, the terminal device can select a configuration length b as the CPE length based on the CAPC level. Alternatively, the terminal device can select a CPE length c when initiating a COT. Alternatively, when sharing the sidelink resources within a COT, the terminal device can select a CPE length d. a, b, c, d can all be one of the N configuration lengths. a, b, c, d can be the same or different.

[0195] It should be noted that the N configuration lengths can be configured by high-level signaling, that is, high-level signaling can be used to configure the configuration lengths supported by the resource pool. For example, when configuring a sidelink resource pool, the configuration parameter set can include a high-level parameter, which can include the CPE length value that the configured resource pool can support (that is, N configuration lengths). For example, the high-level parameter can be represented by CP-extension-SL. CP-extension-SL can satisfy CP-extension-SL = {16, 25, 34, 43, 52, 61}, where the value unit can be microseconds.

[0196] It should be noted that the above embodiments can be implemented individually or in combination.

[0197] The above describes the method embodiment provided by this application. The following describes the device embodiment provided by this application through Figures 22 to 25. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0198] FIG22 is a schematic structural diagram of a terminal device 2200 provided in an embodiment of the present application. The terminal device 2200 may include a first sending unit 2210 .

[0199] The first sending unit 2210 is configured to send a first extended cyclic prefix CPE before communicating through a first sidelink resource; wherein the length of the first CPE is a first length.

[0200] In some embodiments, the first length is determined based on first information indicated by a network device.

[0201] In some embodiments, the first information is carried in first downlink control information DCI, and the first DCI is used to indicate the first sidelink resource that is dynamically scheduled, or the first DCI is used to activate the first sidelink resource allocated by configuring grant type 2.

[0202] In some embodiments, the second DCI includes second information, where the second information is used to indicate a second length, where the second length is the length of the CPE sent before communicating through the second sideline resource, and the second length is the same as or different from the first length.

[0203] In some embodiments, when the first sideline resource and the second sideline resource are used to transmit the same TB, the second length is the same as or different from the first length.

[0204] In some embodiments, the first information is carried in higher layer signaling, and the higher layer signaling is used to configure a sidelink configuration grant.

[0205] In some embodiments, the first sidelink resource belongs to a first resource pool, the first resource pool supports one or more configured lengths, and the first information is used to indicate that the first length is one of the one or more configured lengths.

[0206] In some embodiments, the one or more configuration lengths are configured via higher layer signaling of the network device.

[0207] In some embodiments, the first sidelink resource belongs to a second resource pool, and the second resource pool supports a first configuration length; the first length is determined based on the first configuration length.

[0208] In some embodiments, the first configuration length is configured by the network device, or is preconfigured.

[0209] In some embodiments, the third resource pool supports a second configuration length, and the length of the CPE sent before communication through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When the resources included in the second resource pool and the third resource pool belong to different resource block sets RB sets, the first configuration length and the second configuration length are different or the same.

[0210] In some embodiments, the third resource pool supports a second configuration length, and the length of the CPE sent before communication through the sidelink resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When part or all of the resources in the second resource pool and part or all of the resources included in the third resource pool belong to the same RB set, the first configuration length and the second configuration length are the same.

[0211] In some embodiments, part or all of the resources in the second resource pool and part or all of the resources in the third resource pool share the same RB set by frequency division multiplexing (FDM).

[0212] In some embodiments, the second resource pool is used to perform resource allocation in the first mode or the second mode, and the third resource pool is used to perform resource allocation in the first mode or the second mode.

[0213] In some embodiments, the first length is determined based on a first condition, and the first condition is related to one or more of the following information: the priority of the first CPE; information of the channel occupation time COT initiated by the terminal device;

[0214] The terminal devices share the COT information.

[0215] In some embodiments, the priority includes: the priority indicated by the physical layer of the terminal device and the channel access priority CAPC of the channel access process corresponding to the first CPE.

[0216] In some embodiments, if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30kHz, the first length satisfies: greater than 0 and less than or equal to 1 orthogonal frequency division multiplexing OFDM symbol length; if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30kHz, the first length satisfies: greater than 0 and less than or equal to 2 OFDM symbol lengths.

[0217] In some embodiments, if the terminal device is a terminal device that shares a COT, the first length satisfies: greater than 0 and less than or equal to 1 OFDM symbol length.

[0218] In some embodiments, the first sidelink resource includes one or more resource units, and the resource unit satisfies: corresponding to a sidelink time slot in the time domain, and / or corresponding to one or more resource blocks (RBs) in the frequency domain.

[0219] In some embodiments, the first sidelink resource belongs to an unlicensed spectrum.

[0220] FIG23 is a schematic structural diagram of a network device 2300 provided in an embodiment of the present application. The network device 2300 may include: a second sending unit 2310 .

[0221] The second sending unit 2310 is used to send first information to the terminal device; wherein, the first information is used to indicate a first length, the first length is used to indicate the length of the first extended cyclic prefix CPE, and the first CPE is the CPE sent by the terminal device before communicating through the first sideline resource.

[0222] In some embodiments, the first information is carried in first downlink control information DCI, and the first DCI is used to indicate the first sidelink resource that is dynamically scheduled, or the first DCI is used to activate the first sidelink resource allocated by configuring grant type 2.

[0223] In some embodiments, the second DCI includes second information, where the second information is used to indicate a second length, where the second length is the length of the CPE sent before communicating through the second sideline resource, and the second length is the same as or different from the first length.

[0224] In some embodiments, when the first sideline resource and the second sideline resource are used to transmit the same TB, the second length is the same as or different from the first length.

[0225] In some embodiments, the first information is carried in higher layer signaling, and the higher layer signaling is used to configure a sidelink configuration grant.

[0226] In some embodiments, the first sidelink resource belongs to a first resource pool, the first resource pool supports one or more configured lengths, and the first information is used to indicate that the first length is one of the one or more configured lengths.

[0227] In some embodiments, the one or more configuration lengths are configured via higher layer signaling of the network device.

[0228] In some embodiments, the first sidelink resource belongs to a second resource pool, and the second resource pool supports a first configuration length; the first configuration length is configured through the first information, and the first length is determined based on the first configuration length.

[0229] In some embodiments, the third resource pool supports a second configuration length, and the length of the CPE sent before communication through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When the resources included in the second resource pool and the third resource pool belong to different resource block sets RB sets, the first configuration length and the second configuration length are different or the same.

[0230] In some embodiments, the third resource pool supports a second configuration length, and the length of the CPE sent before communication through the sidelink resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When part or all of the resources in the second resource pool and part or all of the resources included in the third resource pool belong to the same RB set, the first configuration length and the second configuration length are the same.

[0231] In some embodiments, part or all of the resources in the second resource pool and part or all of the resources in the third resource pool share the same RB set by frequency division multiplexing (FDM).

[0232] In some embodiments, the second resource pool is used to perform resource allocation in the first mode or the second mode, and the third resource pool is used to perform resource allocation in the first mode or the second mode.

[0233] In some embodiments, the first length is determined based on a first condition, and the first condition is related to one or more of the following information: the priority of the first CPE; the information of the channel occupancy time COT initiated by the terminal device; and the information of the COT shared by the terminal device.

[0234] In some embodiments, the priority includes: the priority indicated by the physical layer of the terminal device and the channel access priority CAPC of the channel access process corresponding to the first CPE.

[0235] In some embodiments, if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30kHz, the first length satisfies: greater than 0 and less than or equal to 1 orthogonal frequency division multiplexing OFDM symbol length; if the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30kHz, the first length satisfies: greater than 0 and less than or equal to 2 OFDM symbol lengths.

[0236] In some embodiments, if the terminal device is a terminal device that shares a COT, the first length satisfies: greater than 0 and less than or equal to 1 OFDM symbol length.

[0237] In some embodiments, the first sidelink resource includes one or more resource units, and the resource unit satisfies: corresponding to a sidelink time slot in the time domain, and / or corresponding to one or more resource blocks (RBs) in the frequency domain.

[0238] In some embodiments, the first sidelink resource belongs to an unlicensed spectrum.

[0239] In an optional embodiment, the first sending unit 2210 and the second sending unit 2310 may be transceivers 2440, 4. The terminal device 2200 or the network device 2300 may further include a processor 2410 and a memory 2420, as specifically shown in FIG24 .

[0240] Figure 24 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 24 indicate that the unit or module is optional. Device 2400 may be used to implement the method described in the above method embodiment. Device 2400 may be a chip, a terminal device, or a network device.

[0241] The device 2400 may include one or more processors 2410. The processor 2410 may support the device 2400 to implement the method described in the above method embodiment. The processor 2410 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0242] The apparatus 2400 may further include one or more memories 2420. The memories 2420 store programs that can be executed by the processor 2410, causing the processor 2410 to perform the methods described in the above method embodiments. The memories 2420 may be independent of the processor 2410 or integrated into the processor 2410.

[0243] The apparatus 2400 may further include a transceiver 2430. The processor 2410 may communicate with other devices or chips via the transceiver 2430. For example, the processor 2410 may transmit and receive data with other devices or chips via the transceiver 2430.

[0244] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0245] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0246] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0247] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0248] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0249] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0250] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0251] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0252] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0253] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0254] In the embodiments of this application, the term "include" can refer to direct inclusion or indirect inclusion. Alternatively, the term "include" in the embodiments of this application can be replaced with "indicates" or "is used to determine." For example, "A includes B" can be replaced with "A indicates B" or "A is used to determine B."

[0255] In various embodiments of the present application, the size of the above-mentioned serial numbers does not mean the order of execution. The order of execution should be determined by its function and internal logic, and should not constitute any limitation on the implementation of the embodiments of the present application.

[0256] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0257] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0258] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0259] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0260] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A communication method, It is characterized in that include: Before communicating via the first sideline resource, the terminal device sends a first extended cyclic prefix CPE; The length of the first CPE is a first length.

2. The method according to claim 1, It is characterized in that The first length is determined based on first information indicated by the network device.

3. The method according to claim 2, It is characterized in that The first information is carried in first downlink control information DCI, and the first DCI is used to indicate the first sidelink resource that is dynamically scheduled, or the first DCI is used to activate the first sidelink resource allocated by configuring authorization type 2.

4. The method according to claim 3, It is characterized in that The second DCI includes second information, where the second information is used to indicate a second length, where the second length is the length of the CPE sent before communicating through the second sideline resource, and the second length is the same as or different from the first length.

5. The method according to claim 4, Features In the case where the first sideline resource and the second sideline resource are used to transmit the same TB, the second length is the same as or different from the first length.

6. The method according to claim 2, It is characterized in that The first information is carried in a high-layer signaling, and the high-layer signaling is used to configure a sidelink configuration authorization.

7. The method according to any one of claims 2 to 6, It is characterized in that The first sidelink resource belongs to a first resource pool, the first resource pool supports one or more configuration lengths, and the first information is used to indicate that the first length is one of the one or more configuration lengths.

8. The method according to claim 7, It is characterized in that The one or more configuration lengths are configured through high-layer signaling of the network device.

9. The method according to claim 1, It is characterized in that The first sideline resource belongs to a second resource pool, and the second resource pool supports a first configuration length; the first length is determined based on the first configuration length.

10. The method according to claim 9, It is characterized in that The first configuration length is configured by the network device, or is pre-configured.

11. The method according to claim 9 or 10, It is characterized in that The third resource pool supports a second configuration length. The length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When the resources included in the second resource pool and the third resource pool belong to different resource block sets, the first configuration length and the second configuration length are different or the same.

12. The method according to claim 9 or 10, It is characterized in that The third resource pool supports a second configuration length, and the length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When part or all of the resources in the second resource pool and part or all of the resources included in the third resource pool belong to the same resource block set, the first configuration length and the second configuration length are the same.

13. The method according to claim 12, It is characterized in that Part or all of the resources in the second resource pool and part or all of the resources in the third resource pool share the same resource block set by means of frequency division multiplexing FDM.

14. The method according to any one of claims 11 to 13, It is characterized in that The second resource pool is used to perform resource allocation in the first mode or the second mode, and the third resource pool is used to perform resource allocation in the first mode or the second mode.

15. The method according to claim 1, It is characterized in that The first length is determined based on a first condition, where the first condition is related to one or more of the following information: a priority of the first CPE; The terminal device initiates the information of the channel occupancy time COT; The terminal devices share the information of COT.

16. The method according to claim 15, It is characterized in that The priority includes: the priority indicated by the physical layer of the terminal device and the channel access priority CAPC of the channel access process corresponding to the first CPE.

17. The method according to any one of claims 1 to 16, It is characterized in that If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30 kHz, the first length satisfies: greater than 0 and less than or equal to 1 orthogonal frequency division multiplexing OFDM symbol length; If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30 kHz, the first length satisfies: greater than 0 and less than or equal to 2 OFDM symbol lengths.

18. The method according to any one of claims 1 to 16, It is characterized in that If the terminal device is a terminal device that shares a COT, the first length satisfies: greater than 0 and less than or equal to 1 OFDM symbol length.

19. The method according to any one of claims 1 to 18, It is characterized in that The first sidelink resource includes one or more resource units, and the resource unit meets the following requirements: corresponding to a sidelink time slot in the time domain, and / or corresponding to one or more resource blocks RB in the frequency domain.

20. The method according to any one of claims 1 to 19, It is characterized in that The first sidelink resource belongs to an unlicensed spectrum.

21. A communication method, It is characterized in that include: The network device sends first information to the terminal device; The first information is used to indicate a first length, and the first length is used to indicate the length of a first extended cyclic prefix CPE, and the first CPE is a CPE sent by the terminal device before communicating through the first sideline resource.

22. The method according to claim 21, It is characterized in that The first information is carried in first downlink control information DCI, and the first DCI is used to indicate the first sidelink resource that is dynamically scheduled, or the first DCI is used to activate the first sidelink resource allocated by configuring authorization type 2.

23. The method according to claim 22, It is characterized in that The second DCI includes second information, where the second information is used to indicate a second length, where the second length is the length of the CPE sent before communicating through the second sideline resource, and the second length is the same as or different from the first length.

24. The method according to claim 23, It is characterized in that In the case where the first sideline resource and the second sideline resource are used to transmit the same TB, the second length is the same as or different from the first length.

25. The method according to claim 21, It is characterized in that The first information is carried in a high-layer signaling, and the high-layer signaling is used to configure a sidelink configuration authorization.

26. The method according to any one of claims 21 to 25, It is characterized in that The first sidelink resource belongs to a first resource pool, the first resource pool supports one or more configuration lengths, and the first information is used to indicate that the first length is one of the one or more configuration lengths.

27. The method according to claim 26, It is characterized in that The one or more configuration lengths are configured through high-layer signaling of the network device.

28. The method according to claim 21, It is characterized in that The first sideline resource belongs to a second resource pool, and the second resource pool supports a first configuration length; the first configuration length is configured through the first information, and the first length is determined based on the first configuration length.

29. The method according to claim 28, It is characterized in that The third resource pool supports a second configuration length. The length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When the resources included in the second resource pool and the third resource pool belong to different resource block sets, the first configuration length and the second configuration length are different or the same.

30. The method according to claim 28, It is characterized in that The third resource pool supports a second configuration length, and the length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When part or all of the resources in the second resource pool and part or all of the resources included in the third resource pool belong to the same resource block set, the first configuration length and the second configuration length are the same.

31. The method according to claim 30, It is characterized in that Part or all of the resources in the second resource pool and part or all of the resources in the third resource pool share the same resource block set by means of frequency division multiplexing FDM.

32. The method according to any one of claims 29 to 31, It is characterized in that The second resource pool is used to perform resource allocation in the first mode or the second mode, and the third resource pool is used to perform resource allocation in the first mode or the second mode.

33. The method according to claim 21, It is characterized in that The first length is determined based on a first condition, where the first condition is related to one or more of the following information: a priority of the first CPE; The terminal device initiates the information of the channel occupancy time COT; The terminal devices share the information of COT.

34. The method according to claim 33, It is characterized in that The priority includes: the priority indicated by the physical layer of the terminal device and the channel access priority CAPC of the channel access process corresponding to the first CPE.

35. The method according to any one of claims 21 to 34, It is characterized in that If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30 kHz, the first length satisfies: greater than 0 and less than or equal to 1 orthogonal frequency division multiplexing OFDM symbol length; If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30 kHz, the first length satisfies: greater than 0 and less than or equal to 2 OFDM symbol lengths.

36. The method according to any one of claims 21 to 34, It is characterized in that If the terminal device is a terminal device that shares a COT, the first length satisfies: greater than 0 and less than or equal to 1 OFDM symbol length.

37. The method according to any one of claims 21 to 36, It is characterized in that The first sidelink resource includes one or more resource units, and the resource unit meets the following requirements: corresponding to a sidelink time slot in the time domain, and / or corresponding to one or more resource blocks RB in the frequency domain.

38. The method according to any one of claims 21 to 37, It is characterized in that The first sidelink resource belongs to an unlicensed spectrum.

39. A terminal device, It is characterized in that include: A first sending unit, configured to send a first extended cyclic prefix CPE before communicating through a first sideline resource; The length of the first CPE is a first length.

40. The terminal device according to claim 39, It is characterized in that The first length is determined based on first information indicated by the network device.

41. The terminal device according to claim 40, It is characterized in that The first information is carried in first downlink control information DCI, and the first DCI is used to indicate the first sidelink resource that is dynamically scheduled, or the first DCI is used to activate the first sidelink resource allocated by configuring authorization type 2.

42. The terminal device according to claim 41, It is characterized in that The second DCI includes second information, where the second information is used to indicate a second length, where the second length is the length of the CPE sent before communicating through the second sideline resource, and the second length is the same as or different from the first length.

43. The terminal device according to claim 42, It is characterized in that In the case where the first sideline resource and the second sideline resource are used to transmit the same TB, the second length is the same as or different from the first length.

44. The terminal device according to claim 40, It is characterized in that The first information is carried in a high-layer signaling, and the high-layer signaling is used to configure a sidelink configuration authorization.

45. The terminal device according to any one of claims 40 to 44, It is characterized in that The first sidelink resource belongs to a first resource pool, the first resource pool supports one or more configuration lengths, and the first information is used to indicate that the first length is one of the one or more configuration lengths.

46. ​​The terminal device according to claim 45, It is characterized in that The one or more configuration lengths are configured through high-layer signaling of the network device.

47. The terminal device according to claim 39, It is characterized in that The first sideline resource belongs to a second resource pool, and the second resource pool supports a first configuration length; the first length is determined based on the first configuration length.

48. The terminal device according to claim 47, It is characterized in that The first configuration length is configured by the network device, or is pre-configured.

49. The terminal device according to claim 47 or 48, It is characterized in that The third resource pool supports a second configuration length. The length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When the resources included in the second resource pool and the third resource pool belong to different resource block sets, the first configuration length and the second configuration length are different or the same.

50. The terminal device according to claim 47 or 48, It is characterized in that The third resource pool supports a second configuration length, and the length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When part or all of the resources in the second resource pool and part or all of the resources included in the third resource pool belong to the same resource block set, the first configuration length and the second configuration length are the same.

51. The terminal device according to claim 50, It is characterized in that Part or all of the resources in the second resource pool and part or all of the resources in the third resource pool share the same resource block set by means of frequency division multiplexing FDM.

52. The terminal device according to any one of claims 49 to 51, It is characterized in that The second resource pool is used to perform resource allocation in the first mode or the second mode, and the third resource pool is used to perform resource allocation in the first mode or the second mode.

53. The terminal device according to claim 39, It is characterized in that The first length is determined based on a first condition, where the first condition is related to one or more of the following information: a priority of the first CPE; The terminal device initiates the information of the channel occupancy time COT; The terminal devices share the information of COT.

54. The terminal device according to claim 53, It is characterized in that The priority includes: the priority indicated by the physical layer of the terminal device and the channel access priority CAPC of the channel access process corresponding to the first CPE.

55. The terminal device according to any one of claims 39 to 54, It is characterized in that If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30 kHz, the first length satisfies: greater than 0 and less than or equal to 1 orthogonal frequency division multiplexing OFDM symbol length; If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30 kHz, the first length satisfies: greater than 0 and less than or equal to 2 OFDM symbol lengths.

56. The terminal device according to any one of claims 39 to 54, It is characterized in that If the terminal device is a terminal device that shares a COT, the first length satisfies: greater than 0 and less than or equal to 1 OFDM symbol length.

57. The terminal device according to any one of claims 39 to 56, It is characterized in that The first sidelink resource includes one or more resource units, and the resource unit meets the following requirements: corresponding to a sidelink time slot in the time domain, and / or corresponding to one or more resource blocks RB in the frequency domain.

58. The terminal device according to any one of claims 39 to 57, It is characterized in that The first sidelink resource belongs to an unlicensed spectrum.

59. A network device, It is characterized in that include: A second sending unit, configured to send first information to a terminal device; The first information is used to indicate a first length, and the first length is used to indicate the length of a first extended cyclic prefix CPE, and the first CPE is a CPE sent by the terminal device before communicating through the first sideline resource.

60. The network device according to claim 59, It is characterized in that The first information is carried in first downlink control information DCI, and the first DCI is used to indicate the first sidelink resource that is dynamically scheduled, or the first DCI is used to activate the first sidelink resource allocated by configuring authorization type 2.

61. The network device according to claim 60, It is characterized in that The second DCI includes second information, where the second information is used to indicate a second length, where the second length is the length of the CPE sent before communicating through the second sideline resource, and the second length is the same as or different from the first length.

62. The network device according to claim 61, It is characterized in that In the case where the first sideline resource and the second sideline resource are used to transmit the same TB, the second length is the same as or different from the first length.

63. The network device according to claim 59, It is characterized in that The first information is carried in a high-layer signaling, and the high-layer signaling is used to configure a sidelink configuration authorization.

64. The network device according to any one of claims 59 to 63, It is characterized in that The first sidelink resource belongs to a first resource pool, the first resource pool supports one or more configuration lengths, and the first information is used to indicate that the first length is one of the one or more configuration lengths.

65. The network device according to claim 64, It is characterized in that The one or more configuration lengths are configured through high-layer signaling of the network device.

66. The network device according to claim 59, It is characterized in that The first sideline resource belongs to a second resource pool, and the second resource pool supports a first configuration length; the first configuration length is configured through the first information, and the first length is determined based on the first configuration length.

67. The network device according to claim 66, It is characterized in that The third resource pool supports a second configuration length. The length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When the resources included in the second resource pool and the third resource pool belong to different resource block sets, the first configuration length and the second configuration length are different or the same.

68. The network device according to claim 66, It is characterized in that The third resource pool supports a second configuration length, and the length of the CPE sent before communicating through the sideline resources in the third resource pool is the third length. The third length is determined based on the second configuration length. When part or all of the resources in the second resource pool and part or all of the resources included in the third resource pool belong to the same resource block set, the first configuration length and the second configuration length are the same.

69. The network device according to claim 68, It is characterized in that Part or all of the resources in the second resource pool and part or all of the resources in the third resource pool share the same resource block set by means of frequency division multiplexing FDM.

70. The network device according to any one of claims 67 to 69, It is characterized in that The second resource pool is used to perform resource allocation in the first mode or the second mode, and the third resource pool is used to perform resource allocation in the first mode or the second mode.

71. The network device according to claim 59, It is characterized in that The first length is determined based on a first condition, where the first condition is related to one or more of the following information: a priority of the first CPE; The terminal device initiates the information of the channel occupancy time COT; The terminal devices share the information of COT.

72. The network device according to claim 71, It is characterized in that The priority includes: the priority indicated by the physical layer of the terminal device and the channel access priority CAPC of the channel access process corresponding to the first CPE.

73. The network device according to any one of claims 59 to 72, It is characterized in that If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is less than 30 kHz, the first length satisfies: greater than 0 and less than or equal to 1 orthogonal frequency division multiplexing OFDM symbol length; If the terminal device is a terminal device that initiates COT, when the subcarrier spacing is greater than or equal to 30 kHz, the first length satisfies: greater than 0 and less than or equal to 2 OFDM symbol lengths.

74. The network device according to any one of claims 59 to 72, It is characterized in that If the terminal device is a terminal device that shares a COT, the first length satisfies: greater than 0 and less than or equal to 1 OFDM symbol length.

75. The network device according to any one of claims 59 to 74, It is characterized in that The first sidelink resource includes one or more resource units, and the resource unit meets the following requirements: corresponding to a sidelink time slot in the time domain, and / or corresponding to one or more resource blocks RB in the frequency domain.

76. The network device according to any one of claims 59 to 75, It is characterized in that The first sidelink resource belongs to an unlicensed spectrum.

77. A terminal device, It is characterized in that The method comprises a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory so that the terminal device executes the method according to any one of claims 1 to 20.

78. A network device, It is characterized in that It comprises a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory so that the network device executes the method as described in any one of claims 21-38.

79. A device, It is characterized in that It comprises a processor, which is used to call a program from a memory so that the device executes the method as claimed in any one of claims 1 to 38.

80. A chip, It is characterized in that It comprises a processor, which is used to call a program from a memory so that a device equipped with the chip executes a method as claimed in any one of claims 1 to 38.

81. A computer readable storage medium, It is characterized in that A program is stored thereon, the program causing a computer to execute the method according to any one of claims 1 to 38.

82. A computer program product, It is characterized in that The method comprises a program which causes a computer to execute the method according to any one of claims 1 to 38.

83. A computer program, It is characterized in that The computer program causes a computer to execute the method according to any one of claims 1 to 38.

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