Sidelink transmission methods and terminal devices

Abstract

Provided are sidelink transmission methods and terminal devices. A sidelink transmission method comprises: a first terminal device repeatedly transmits first sidelink data in N consecutive time slots, the transmit power of each time slot among the N time slots being less than first transmit power, the first transmit power being less than or equal to the maximum allowable transmit power of the first terminal device, and N being a positive integer greater than 1. Using low power to transmit the same sidelink data in continuous N time slots can not only ensure coverage performance, but also save the energy consumption of terminal devices.

Description

Side transmission method and terminal device Technical Field

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

[0002] Sideline communication systems typically transmit sideline data in time slots. During sideline data transmission, ensuring coverage while reducing energy consumption in terminal devices is a challenge that needs to be addressed.

[0003] Summary of the Invention

[0004] The present application provides a side transmission method and terminal device. The following introduces various aspects involved in the present application.

[0005] In a first aspect, a sideline transmission method is provided, comprising: a first terminal device repeatedly transmits first sideline data in N consecutive time slots, the transmission power of each time slot in the N time slots is less than a first transmission power, the first transmission power is less than or equal to the maximum transmission power allowed by the first terminal device, and N is a positive integer greater than 1.

[0006] In a second aspect, a sideline transmission method is provided, comprising: a second terminal device receives first sideline data in S time slots out of N consecutive time slots, the N time slots are used to repeatedly transmit the first sideline data, N is a positive integer greater than 1, and S is a positive integer less than or equal to N.

[0007] According to a third aspect, a terminal device is provided, which is a first terminal device, and includes: a communication module for repeatedly transmitting first sidelink data in N consecutive time slots, the transmission power of each time slot in the N time slots is less than a first transmission power, the first transmission power is less than or equal to the maximum transmission power allowed by the first terminal device, and N is a positive integer greater than 1.

[0008] In a fourth aspect, a terminal device is provided, which is a second terminal device, and the terminal device includes: a communication module for receiving first side-line data in S time slots out of N consecutive time slots, and the N time slots are used to repeatedly transmit the first side-line data, N is a positive integer greater than 1, and S is a positive integer less than or equal to N.

[0009] In a fifth aspect, a terminal device is provided, comprising a transceiver, a memory and a processor, wherein the memory is used to store programs, and the processor is used to call the programs in the memory and control the transceiver to receive or send signals so that the terminal executes the method as described in any one of the first to second aspects.

[0010] In a sixth aspect, a device is provided, comprising a processor for calling a program from a memory so that the device executes the method as described in any one of the first to second aspects.

[0011] In a seventh aspect, a chip is provided, comprising a processor for calling a program from a memory so that a device equipped with the chip executes a method as described in any one of the first to second aspects.

[0012] In an eighth aspect, a computer-readable storage medium is provided, on which a program is stored, wherein the program enables a computer to execute the method as described in any one of the first to second aspects.

[0013] In a ninth aspect, a computer program product is provided, comprising a program, wherein the program enables a computer to execute the method as described in any one of the first to second aspects.

[0014] In a tenth aspect, a computer program is provided, which enables a computer to execute the method as described in any one of the first to second aspects.

[0015] The embodiment of the present application uses lower power to transmit the same sideline data in N consecutive time slots, which can both ensure coverage performance and save energy of the terminal device. 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 showing an example of a side communication scenario based on 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] FIG. 9A is a diagram illustrating an example of a time slot structure used by a sideline communication system.

[0025] FIG. 9B is another diagram illustrating an example of a time slot structure used by the sideline communication system.

[0026] FIG10 is a diagram illustrating an example of the time domain relationship between a physical sidelink shared channel demodulation reference signal (PSSCH DM-RS) and second-order sidelink control information (SCI).

[0027] FIG11 is a comparison diagram of the time slot structures corresponding to multiple transmissions of the PSSCH.

[0028] FIG12 is a diagram showing an example of mapping of a physical sidelink control channel (PSCCH) DM-RS.

[0029] FIG13 is a diagram showing an example of a time domain mapping method for PSSCH DM-RS.

[0030] FIG14 is a diagram showing an example of a frequency domain mapping method for PSSCH DM-RS.

[0031] FIG15 is a diagram illustrating an example of mapping of a channel state information reference signal (CSI-RS) in a sidelink.

[0032] FIG16 is an example diagram of the listen before talk (LBT) process.

[0033] FIG17 is a diagram showing an example of the transmission power of PSSCH / PSCCH.

[0034] FIG18 is a flow chart of a side transmission method provided in accordance with an embodiment of the present application.

[0035] FIG19 is an example diagram of a power allocation method during repeated transmission of side data provided in an embodiment of the present application.

[0036] FIG20 is another example diagram of the power allocation method during repeated transmission of side data provided in an embodiment of the present application.

[0037] FIG21 is another example diagram of the power allocation method during repeated transmission of side data provided in an embodiment of the present application.

[0038] FIG22 is a flow chart of a side transmission method provided in another embodiment of the present application.

[0039] FIG23 is a schematic diagram of the structure of a terminal device provided in one embodiment of the present application.

[0040] FIG24 is a schematic structural diagram of a terminal device provided in another embodiment of the present application.

[0041] FIG25 is a schematic diagram of the structure of the device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0042] Communication system architecture

[0043] FIG1 is a diagram illustrating an exemplary system architecture of a wireless communication system 100 to which embodiments of the present application may be applied. 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 within the coverage area.

[0044] FIG1 exemplarily shows a network device and a terminal device. Optionally, the wireless communication system 100 may include one or more network devices 110 and / or one or more terminal devices 120. For a network device 110, the one or more terminal devices 120 may all be located within the network coverage of the network device 110, or all be located outside the network coverage of the network device 110, or some may be located within the coverage of the network device 110 and others outside the network coverage of the network device 110. This is not limited in the embodiments of the present application.

[0045] 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 embodiment of the present application.

[0046] 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.

[0047] The terminal device in the embodiment 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 device, mobile device, user terminal, wireless communication device, user agent or user device. The terminal device in the embodiment of the present application may be 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 embodiment of the present application may be a mobile phone, a tablet computer (Pad), a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a vehicle, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. For example, a terminal device can act as a dispatching entity, providing sidelink signals between terminal devices in vehicle-to-everything (V2X) or device-to-device (D2D) communications. For example, a cell phone and a car can communicate with each other using sidelink signals. A cell phone and a smart home device can also communicate without relaying the communication signal through a base station. Alternatively, the terminal device can be used to act as a base station.

[0048] 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 may 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, transmitting and receiving point (TRP), transmitting 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 may 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 may also refer to a communication module, modem, or chip used to be set in the aforementioned device or apparatus. A base station may also be a mobile switching center and a device that performs base station functions in device-to-device D2D, V2X, or machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. A base station may support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by network devices.

[0049] 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.

[0050] 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 may include a CU and a DU. The gNB may also include an AAU.

[0051] 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.

[0052] Sideline communication under different network coverage conditions

[0053] Sidelink communication refers to a communication technology based on a sidelink. Sidelink communication can be, for example, device-to-device (D2D) or vehicle-to-everything (V2X) communication. In traditional cellular systems, communication data is received or sent between terminal devices and network devices, while sidelink communication supports direct communication and data transmission between terminal devices. Compared with traditional cellular communication, direct communication data transmission between terminal devices can have higher spectrum efficiency and lower transmission latency. For example, the vehicle networking system adopts sidelink communication technology.

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

[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] Sideline communication based on central control node

[0059] Figure 5 is an example diagram of a sideline communication scenario based on a central control node. In this sideline communication scenario, multiple terminal devices can form a communication group, and the communication group has a central control node. The central control node can be a terminal device in the communication group (such as terminal device 1 in Figure 5), and the terminal device can also be called a cluster head (CH) terminal device. The central control node can be responsible for completing one or more of the following functions: establishing a communication group, joining and leaving group members of the communication group, coordinating resources within the communication group, allocating sideline transmission resources to other terminal devices, receiving sideline feedback information from other terminal devices, and coordinating resources with other communication groups.

[0060] Sideline communication mode

[0061] Some standards or protocols (such as the 3rd Generation Partnership Project (3GPP)) define two sideline communication modes: a first mode and a second mode.

[0062] In the first mode, the resources of the terminal device (the resources mentioned in this application may also be referred to as transmission resources, such as 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.

[0063] 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.

[0064] Data transmission method of side communication

[0065] Some sidewalk communication systems (such as long-term evolution vehicle to everything (LTE-V2X)) support broadcast-based data transmission (hereinafter referred to as broadcast transmission). For broadcast transmission, the receiving terminal can be any terminal device around the transmitting terminal. Taking Figure 6 as an example, terminal device 1 is the transmitting terminal, and the receiving terminal corresponding to the transmitting terminal is any terminal device around terminal device 1, for example, terminal device 2 to terminal device 6 in Figure 6.

[0066] 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, the new radio vehicle to everything (NR-V2X) hopes to support autonomous driving. Autonomous driving places higher requirements on data interaction between vehicles. For example, data interaction between vehicles requires higher throughput, lower latency, higher reliability, larger coverage, more flexible resource allocation, etc. Therefore, in order to improve the performance of data interaction between vehicles, NR-V2X introduces unicast transmission and multicast transmission.

[0067] For unicast transmission, there is typically only one receiving terminal. For example, in Figure 7, unicast transmission occurs between terminal devices 1 and 2. Terminal device 1 can be the sending terminal, and terminal device 2 can be the receiving terminal, or vice versa.

[0068] For multicast transmission, the receiving terminal can be a terminal device within a communication group, or a terminal device within a certain transmission distance. For example, in Figure 8, terminal devices 1, 2, 3, and 4 form a communication group. If terminal device 1 sends data, all other terminal devices in the group (terminal devices 2 through 4) can be receiving terminals.

[0069] Time slot structure for sideline communication

[0070] The communication system may define a frame, subframe, or time slot structure for sidelink communication. Some sidelink communication systems define multiple time slot structures. For example, NR-V2X defines two time slot structures. One of the two time slot structures does not include a physical sidelink feedback channel (PSFCH), see Figure 9A; the other of the two time slot structures includes a PSFCH, see Figure 9B.

[0071] The physical sidelink control channel (PSCCH) in NR-V2X can start at the second sidelink symbol of the time slot in the time domain, and the PSCCH can occupy 2 or 3 symbols in the time domain (the symbols mentioned here can all refer to orthogonal frequency division multiplexing (OFDM) symbols). The PSCCH can occupy multiple physical resource blocks (PRBs) in the frequency domain. For example, the number of PRBs occupied by the PSCCH can be selected from the following values: {10, 12 15, 20, 25}.

[0072] To reduce the complexity of blind detection of PSCCH by terminal devices, typically, only one number of symbols and PRBs is configured for PSCCH within a resource pool. Furthermore, since NR-V2X uses sub-channels as the minimum granularity for PSSCH resource allocation, the number of PRBs occupied by PSCCH must be less than or equal to the number of PRBs contained in a sub-channel within the resource pool.

[0073] Referring to Figure 9A, for a time slot structure that does not include PSFCH, the PSSCH in NR-V2X can use the second side symbol of the time slot as the starting position in the time domain. The last side symbol in the time slot is used as a guard period (GP), and the remaining symbols can be mapped to PSSCH. The first side symbol in the time slot can be a repetition of the second side symbol. Generally speaking, the terminal device at the receiving end will use the first side symbol as a symbol for automatic gain control (AGC). Therefore, the data on the first side symbol is usually not used for data demodulation. PSSCH can occupy K subchannels in the frequency domain, and each subchannel can include M consecutive PRBs (the values ​​of K and M can be predefined by the protocol, or preconfigured, or configured by the network device, or depend on the terminal device implementation).

[0074] FIG9B illustrates a time slot structure including the PSFCH, schematically illustrating the positions of the symbols occupied by the PSFCH, PSCCH, and PSSCH in a time slot. The primary difference between this time slot structure and FIG9A is that the penultimate and third-to-last symbols in a time slot are used for PSFCH transmission. Furthermore, the symbol preceding the symbol used for PSFCH transmission also serves as the GP. As can be seen from the time slot structure shown in FIG9B , in a time slot, the last symbol serves as the GP, the second-to-last symbol is used for PSFCH transmission, and the data on the third-to-last symbol is the same as the data on the second-to-last symbol used for PSFCH transmission. That is, the third-to-last symbol serves as the symbol for AGC, while the fourth-to-last symbol has the same function as the last symbol and also serves as the GP. Furthermore, the first symbol in a time slot is used for AGC, and the data on this symbol is the same as the data on the second symbol in the time slot. PSCCH occupies three symbols, and the remaining symbols can be used for PSSCH transmission.

[0075] Sideways PSSCH

[0076] In some sideline communication systems (such as NR SL systems), PSSCH can be used to carry the second-order SCI (2 nd The format of the second-stage SCI may be, for example, SCI 2-A, SCI 2-B or SCI 2-C.

[0077] The second-order SCI encoding method may adopt an encoding method based on a polar code (polar code), and adopt a quadrature phase shift keying (QPSK) modulation method for modulation.

[0078] The code rate of the second-order SCI can be dynamically adjusted within a certain range, and the code rate used by the second-order SCI can be indicated by the first-order SCI. Therefore, even if the code rate of the second-order SCI changes, the terminal device as the receiving end does not need to perform blind detection on the second-order SCI. The modulation symbol of the second-order SCI can start from the symbol where the first DM-RS of the PSSCH is located, and is mapped in the frequency domain first and then the time domain. In the symbol where the DM-RS is located, the second-order SCI can be mapped to the RE not occupied by the DM-RS. Taking Figure 10 as an example, the second-order SCI occupies symbols 1 to 4, and the second-order SCI shares symbol 1 with the first PSCCH DM-RS.

[0079] The data information of the PSSCH can be encoded using a low-density parity check (LDPC) code. In addition, the highest modulation order currently supported by the PSSCH is 256-bit quadrature amplitude modulation (QAM).

[0080] Within a resource pool, PSSCH data information can use multiple different modulation and coding scheme (MCS) tables. These multiple different MCS tables can include, for example, a conventional 64QAM MCS table, a 256QAM MCS table, and a low-spectrum-efficiency 64QAM MCS table. During a PSSCH transmission, the MCS table used by the transmitting terminal device can be indicated by the "MCS Table Indication" field in the first-order SCI.

[0081] To control the peak-to-average power ratio (PAPR), the PSSCH typically needs to be transmitted on contiguous PRBs. In NR SL systems, a subchannel is the minimum frequency-domain resource granularity for the PSSCH. Therefore, to control the PAPR, NR SL systems typically require the PSSCH to occupy contiguous subchannels.

[0082] Furthermore, in the NR SL system, the PSSCH supports up to two-stream transmission, and uses a unit matrix precoding matrix to map the data on the two transmission layers corresponding to the two streams to two antenna ports. Currently, at most one transmission block (TB) can be sent in a PSSCH. When the PSSCH adopts a dual-stream transmission mode, the modulation symbols of the second-order SCI on the two streams can be exactly the same. This design can ensure the reception performance of the second-order SCI in highly correlated channels.

[0083] In the NR SL system, the maximum number of retransmissions of a PSSCH is 32 times. Therefore, if there are PSFCH resources in the resource pool and the configuration period of the PSFCH resources is 2 or 4, the number of available symbols in the time slot where the PSSCH is located may change for multiple transmissions of the same PSSCH. For example, referring to Figure 11, the PSSCH is transmitted for the nth time in time slot a and for the n+1th time in time slot b. It can be seen from Figure 11 that there are PSFCH resources and their corresponding related resources (such as AGC symbols and GP symbols corresponding to the PSFCH, etc., see the description of Figure 9B for details) in time slot a, and there is no PSFCH in time slot b. Therefore, due to the change of PSFCH resources, the number of available symbols in the time slot is different in the nth transmission and the n+1th transmission. The change of available symbols in the time slot will cause the transmission block size (TBS) corresponding to the PSSCH to change. Therefore, in order to ensure that the TBS of PSSCH remains unchanged during multiple transmissions, the actual number of PSFCH symbols may not be used when calculating TBS. Instead, the number of PSFCH symbols used to calculate TBS may be determined based on the indication information in the first-order SCI. For a detailed description, see the description in the next section.

[0084] Sideways TBS

[0085] In some sideline communication systems (such as NR SL systems), PSSCH follows the TBS determination mechanism of the physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) in the NR system, that is, the TBS is determined according to 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. In other words, when determining TBS, such sideline communication systems do not use the actual number of REs occupied by PSSCH, but use the reference value of the number of REs of PSSCH. The purpose of this is to ensure that the number of REs used to determine TBS remains unchanged during the retransmission of PSSCH, so that the TBS size determined by different transmission processes of PSSCH is the same. Reference value N of the number of REs occupied by PSSCH RE It can be determined based on formula (1):

[0086] In the above formula (1), n PRB Indicates the number of PRBs occupied by PSSCH, Indicates the number of REs occupied by the first-order SCI ( It may include the number of REs occupied by the DM-RS of the PSCCH), Indicates the number of REs occupied by the second-order SCI, N′ RE Indicates the number of reference REs that can be used for PSSCH in a PRB.

[0087] N′ RE It can be determined based on the following formula (2):

[0088] In the above formula (2), Indicates the number of subcarriers in a PRB, The value is usually 12. Indicates the number of symbols available for sideline transmission in a time slot. Usually, the last symbol (i.e., GP symbol) and the first symbol (i.e., symbol used for AGC) of a time slot are not included. Taking the time slot structure shown in Figure 10 as an example, A reference value indicating the number of symbols occupied by the PSFCH. The value of can be indicated by the "PSFCH symbol number" field in the first-order SCI. The value of is usually 0 or 3. Indicates the reference value of the number of REs occupied by the phase tracking reference signals (PT-RS) and CSI-RS. The value of can be configured by radio resource control (RRC) parameters. Indicates the average number of REs in the DM-RS pattern in one slot. The value of is related to the DM-RS pattern supported in the resource pool, as shown in Table 1. Referring to Table 1, when the DM-RS pattern includes three patterns {2, 3, 4}, The value of is 18, that is, the average number of REs of the three DM-RS patterns is 18.

[0089] Table 1: DM-RS patterns allowed in a resource pool The corresponding relationship

[0090] Side DM-RS

[0091] In the NR SL system, the DM-RS pattern of PSCCH is the same as the DM-RS pattern of PDCCH in the NR system, that is, DM-RS exists on every symbol of PSCCH and is located on the REs corresponding to {#1, #5, #9} in a PRB in the frequency domain, as shown in Figure 12.

[0092] The DM-RS sequence of PSCCH can be generated by formula (3):

[0093] In the above formula (3), c(m) represents a pseudo-random sequence. The pseudo-random sequence can be initialized based on the following formula (4):

[0094] In the above formula (4), l represents the index of the symbol where the DM-RS is located in the time slot. Indicates the index of the time slot where the DM-RS is located in the system frame. Indicates the number of symbols in a time slot. NID∈{0,1,…,65535}. In a resource pool, N ID The value can be configured or pre-configured by the network device.

[0095] The PSSCH of the NR SL system draws on the design of the NR air interface (i.e., Uu interface), that is, it uses multiple time-domain PSSCH DM-RS patterns. Within a resource pool, the number of available DM-RS patterns is related to the number of PSSCH symbols in the resource pool (including the first AGC symbol). For a specific number of PSSCH symbols and PSCCH symbols, the available DM-RS patterns and the position of each DM-RS symbol within the DM-RS pattern can be determined based on Table 2.

[0096] Table 2: Number and position of DM-RS symbols in a time slot for different PSSCH and PSCCH symbol numbers

[0097] Taking the number of PSSCH symbols as 13 as an example, see Figure 13, when the number of DM-RS symbols is 4, the 4 DM-RS symbols occupy the 1st, 4th, 7th, and 10th symbol positions (or symbol indexes) in the time slot respectively.

[0098] If multiple DM-RS patterns are configured in the time domain within a resource pool, the transmitting terminal device can select the specific DM-RS pattern to use and indicate this in the first-order SCI. This design allows high-speed terminal devices to select a high-density DM-RS pattern, thereby ensuring channel estimation accuracy; correspondingly, for low-speed terminal devices, a low-density DM-RS pattern can be used, thereby improving spectral efficiency.

[0099] The generation method of the PSSCH DM-RS sequence is similar to that of the PSCCH DM-RS sequence. The difference between the two lies in the initialization formula of the pseudo-random sequence c(m) (corresponding to the formula (4) above) where N IDThe value of. In the pseudo-random sequence c(m) used to generate the PSSCH DM-RS sequence, Among them, p i represents the cyclic redundancy check (CRC) of the PSCCH that schedules the PSSCH, L represents the number of bits of the PSCCH CRC, and the value of L is usually 24.

[0100] In the NR system, PDSCH and PUSCH support two frequency domain DM-RS patterns, namely DM-RS frequency domain type 1 and DM-RS frequency domain type 2. Furthermore, for each frequency domain type of DM-RS, there are two different symbol types: single symbol and dual symbol. Single symbol DM-RS frequency domain type 1 can support 4 DM-RS ports. Single symbol DM-RS frequency domain type 2 can support 6 DM-RS ports. The number of DM-RS ports supported by dual symbol DM-RS frequency domain type 1 is twice the number of DM-RS ports supported by single symbol DM-RS frequency domain type 1. The number of DM-RS ports supported by dual symbol DM-RS frequency domain type 2 is twice the number of DM-RS ports supported by single symbol DM-RS frequency domain type 2. However, in some sideline communication systems (such as NR SL systems), since PSSCH needs to support a maximum of two DM-RS ports, such communication systems generally only support single symbol DM-RS frequency domain type 1, and the frequency domain pattern of this type of DM-RS is shown in Figure 14.

[0101] Side CSI-RS

[0102] To better support unicast communication, the NR-V2X system supports SL CSI-RS. The NR-V2X system specifies that SL CSI-RS will be sent only when the following three conditions are met:

[0103] Condition 1: The terminal device needs to send the PSSCH corresponding to the SL CSI-RS, that is, the terminal device cannot only send the SL CSI-RS.

[0104] Condition 2: Sidelink CSI reporting is activated through higher layer signaling.

[0105] Condition 3: When high-layer signaling activates sidelink CSI reporting, the corresponding bit in the second-order SCI sent by the terminal device triggers sidelink CSI reporting.

[0106] The maximum number of ports supported by SL CSI-RS is 2. For two ports, SL CSI-RSs from different ports are code-division multiplexed on two adjacent REs in the same sidelink symbol. Within a PRB, the number of SL CSI-RSs per port is 1, meaning the density is 1. Therefore, within a PRB, an SL CSI-RS appears on at most one sidelink symbol. The specific location of this sidelink symbol is determined by the terminal device transmitting the SL CSI-RS.

[0107] Generally, in order to avoid affecting the resource mapping of PSCCH and second-order SCI, SL CSI-RS cannot be located in the same sidebar symbol as PSCCH and second-order SCI.

[0108] In addition, since the channel estimation accuracy of the sidelink symbol where the PSSCH DM-RS is located is higher and the SL CSI-RS of the two ports will need to occupy two consecutive REs in the frequency domain, the SL CSI-RS and the PSSCH DM-RS cannot be sent through the same sidelink symbol.

[0109] In some cases, the position of the side symbol occupied by the SL CSI-RS can be indicated by the sl-CSI-RS-FirstSymbol parameter in PC5RRC. In addition, the position of the first RE occupied by the SL CSI-RS in a PRB is indicated by the "sl-CSI-RS-FreqAllocation" parameter in PC5RRC. If the SL CSI-RS corresponds to one port, the parameter is a bitmap with a length of 12, corresponding to 12 REs in one PRB. If the SL CSI-RS corresponds to two ports, the parameter is a bitmap with a length of 6. In this case, the SL CSI-RS occupies two REs, 2f(1) and 2f(1)+1, where f(1) represents the identifier of the bit with a value of 1 in the above bitmap.

[0110] The frequency domain position occupied by the SL CSI-RS is also determined by the terminal device that sends the SL CSI-RS, and it should be noted that the determined frequency domain position of the SL CSI-RS cannot conflict with the frequency domain position occupied by the PT-RS.

[0111] Figure 15 shows a schematic diagram of the time-frequency resources occupied by the SL CSI-RS. Assume in Figure 15 that the number of ports corresponding to the SL CSI-RS is 2, sl-CSI-RS-FirstSymbol indicates that the SL CSI-RS occupies side symbol position 8, and sl-CSI-RS-FreqAllocation indicates that the position of the first RE occupied by the SL CSI-RS within a PRB is [b5, b4, b3, b1, b2, b0] = [0, 0, 0, 1, 0, 0].

[0112] Unlicensed spectrum and channel monitoring

[0113] Unlicensed spectrum is a spectrum designated by countries and regions for use by radio equipment. This spectrum is generally considered shared. This means that communications equipment within the same or different systems can use this spectrum as long as they meet national or regional regulatory requirements for that spectrum, without having to apply for exclusive spectrum authorization from the government.

[0114] To ensure friendly coexistence among various communication devices (or communication systems) using unlicensed spectrum for wireless communications, some countries or regions have established regulatory requirements for the use of unlicensed spectrum. For example, communication devices adhere to the listen before talk (LBT) principle. LBT means that before a communication device transmits a signal on an unlicensed spectrum channel, it must first perform channel sensing. If the channel sensing result indicates that the channel is idle, the communication device can use the unlicensed spectrum channel for signal transmission; if the channel sensing result indicates that the channel is busy, the communication device is generally not allowed to use the unlicensed spectrum channel for signal transmission. To ensure fairness, the duration of a communication device's signal transmission using an unlicensed spectrum channel cannot exceed the maximum channel occupancy time (MCOT) during a single transmission. Figure 16 shows an example of a channel occupancy time obtained by a communication device after successful LBT on an unlicensed spectrum channel, and the use of resources within the channel occupancy time for signal transmission.

[0115] Although channel monitoring based on LBT is not a global regulatory requirement, channel monitoring can bring the benefits of interference avoidance and friendly coexistence to communication transmissions between communication systems on shared spectrum. Therefore, in the design process of NR systems on unlicensed spectrum, channel monitoring is a feature that must be supported by communication equipment in the system. From the perspective of system networking, channel monitoring includes two mechanisms. One is LBT based on load-based equipment (LBE), also known as dynamic channel monitoring or dynamic channel occupancy; the other is LBT based on frame-based equipment (FBE), also known as semi-static channel monitoring or semi-static channel occupancy.

[0116] The following focuses on several different types of LBT methods (i.e., several different types of channel access methods).

[0117] Type 1 LBT method (Type 1 LBT method) can also be called multi-slot channel detection based on random backoff of contention window size adjustment. In Type 1 LBT method, the communication device can initiate a channel access priority p with a length of T mcot The following table shows the channel access priority and corresponding parameters when the terminal device performs type 1 LBT.

[0118] Table 3 Channel access parameters corresponding to different channel priorities

[0119] In the above Table 1, m p Refers to the number of fallback slots corresponding to the channel access priority p, CW p Refers to the contention window size corresponding to the channel access priority p, CW min,p Refers to the CW corresponding to the channel access priority p p Minimum value, CW max,p Refers to the CW corresponding to the channel access priority p p The maximum value, T mcot,p Refers to the maximum channel occupancy time length corresponding to the channel access priority p. Among the four channel access priorities shown in Table 1, p=1 is the highest priority.

[0120] If a network device uses the Type 1 LBT method, the network device can not only send its own data during the channel occupancy period, but also share the channel occupancy time (COT) with the terminal device. Correspondingly, if a terminal device uses the Type 1 LBT method, the terminal device can not only send its own data during the channel occupancy period, but also share the COT with the network device or other terminal devices. Resource sharing within the COT can use the Type 2 LBT method (Type 2 LBT method) for channel access. The Type 2 LBT method (Type 2 LBT method) can also be called a channel access method based on a fixed-length channel listening time slot. The Type 2 LBT method includes the Type 2A LBT method (Type 2A LBT method), the Type 2B LBT method (Type 2B LBT method), and the Type 2C LBT method (Type 2C LBT method).

[0121] In Type 2A LBT, a communication device can use a 25us channel detection cycle. This means the device can begin channel detection 25us before starting to send data. This 25us channel detection cycle can include one 16us channel detection cycle and one 9us channel detection cycle. If both detections indicate the channel is idle, the channel is considered idle and can be accessed.

[0122] In Type 2B LBT, a communication device can use 16us channel detection. During the channel detection process, if the communication device detects that the channel is idle for at least 5us within the 26us, and that the channel is idle for more than 4us within the last 9us, the channel is considered idle.

[0123] In Type 2C LBT, communication devices can transmit data directly over the channel without performing channel detection. In Type 2C LBT, the time difference between the current transmission and the previous transmission must be less than or equal to 16µs. In other words, if the time difference between two transmissions is less than or equal to 16µs, they are considered the same transmission and channel detection is not required. It should be noted that in Type 2C LBT, the transmission duration of communication devices is limited and generally cannot exceed 584µs.

[0124] Channel access parameter indication (including cyclic prefix extension (CPE))

[0125] In the new radio unlicensed (NR-U) system, when the 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). 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 CPE. Accordingly, the network device can indicate the CPE length of the first symbol of the uplink transmission of the terminal device.

[0126] 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.

[0127] The following describes how to indicate channel access parameters introduced in different DCI formats.

[0128] First: Fallback uplink grant for scheduling PUSCH transmission (DCI format 0_0)

[0129] The standard pre-sets a set of channel access mode and CPE length joint indications, as shown in Table 4 below. The fallback uplink grant includes 2-bit LBT indication information, which is used to indicate the jointly encoded channel access mode and CPE length from the set shown in Table 4. The channel access mode and CPE length are used for PUSCH transmission. If the channel access mode is Type 1 channel access, the terminal device selects the channel access priority class (CAPC) based on the service priority.

[0130] Second: Fallback downlink grant for scheduling PDSCH transmission (DCI format 1_0)

[0131] The set of channel access mode and CPE length joint indications preset in the standard is shown in Table 4 below. The fallback downlink authorization includes 2-bit LBT indication information. 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. The PUCCH can carry the acknowledgment (ACK) or negative acknowledgment (NACK) information corresponding to the PDSCH. If the channel access mode is Type 1 channel access, the terminal device determines the channel access priority CAPC = 1 for transmitting PUCCH.

[0132] Table 4 Channel access mode and CPE length joint indication set

[0133] 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.

[0134] Third: Non-fallback uplink grant for scheduling PUSCH transmission (DCI format 0_1)

[0135] The higher layer configures the LBT parameter indication set. The LBT parameter indication set includes at least one jointly coded channel access method, CPE length and CAPC. The non-fallback uplink authorization includes LBT indication information, and 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. The LBT indication information includes a maximum of 6 bits.

[0136] Fourth: Non-fallback downlink grant for scheduling PDSCH transmission (DCI format 1_1)

[0137] The high-level layer configures the LBT parameter indication set. The LBT parameter indication set includes at least one jointly coded channel access method and CPE length. The non-fallback downlink authorization includes LBT indication information, and the LBT indication information is used to indicate the jointly coded channel access method and CPE length from the above-mentioned LBT parameter indication set. The channel access method and CPE length are used for PUCCH transmission, wherein 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 determines that the channel access priority CAPC=1 for transmitting the PUCCH. The LBT indication information includes a maximum of 4 bits.

[0138] In addition to the above explicit indications, the network device can also implicitly indicate the channel access method within the COT. For example, when a terminal device receives an UL grant or DL ​​grant sent by a network device, and the UL grant or DL ​​grant indicates that the channel access type corresponding to the PUSCH or PUCCH is Type 1 channel access, if the terminal device can determine that the transmission time of the PUSCH or PUCCH is within the COT of the network device, then the terminal device can update the channel access type corresponding to the PUSCH or PUCCH to Type 2A channel access instead of Type 1 channel access.

[0139] Sidelink power control

[0140] The NR SL system supports open-loop control of the transmit power of PSSCH, PSCCH, PSFCH, and sidelink synchronization signal block (S-SSB). For the transmission of PSSCH and PSCCH in unicast scenarios, three power control methods can be supported: power control based only on downlink path loss, power control based only on sidelink path loss, and power control based on downlink path loss and sidelink path loss. Which power control method PSSCH and PSCCH actually need to adopt can be determined by the high-level (RRC layer) configuration. For example, if the high-level layer only configures the basic working point P for power control based on sidelink path loss, 0,SL , it means that power control is performed based only on the sidelink path loss; if the upper layer only configures the basic working point P for power control based on the downlink path loss 0,D , it means that power control is performed based on downlink path loss only; if the upper layer configures P 0,SL and P 0,D , it means that power control is performed based on the downlink path loss and the sidelink path loss.

[0141] For the transmission of PSFCH and S-SSB, as well as the transmission of PSSCH and PSCCH in multicast and broadcast scenarios, since the terminal device as the transmitter does not obtain the sidelink path loss information, only open-loop power control based on the downlink path loss is supported.

[0142] In the LTE-V2X system, the PSCCH and PSSCH are frequency-division multiplexed. Unlike LTE-V2X, in the NR-V2X system, the PSCCH transmission resources are embedded within the PSSCH transmission resources. The LTE-V2X system performs a 3dB power boost on the PSCCH to improve PSCCH detection performance. In the NR-V2X system, if the 3dB power boost is applied to the PSCCH using the same method as in the LTE-V2X system, the PSSCH power per resource element in the time-domain symbols containing the PSCCH will be inconsistent with the PSSCH power per resource element in the time-domain symbols not containing the PSCCH, which will degrade PSSCH demodulation performance. Considering that the NR-V2X system can adjust the PSCCH channel code rate by configuring the number of symbols occupied by the PSCCH and the number of PRBs, thereby ensuring PSCCH demodulation performance, the 3dB power boost is not applied to the PSCCH in the NR-V2X system.

[0143] PSSCH / PSCCH power control

[0144] The transmit power of the PSSCH on a symbol including only the PSSCH can be determined as follows:

[0145] If the terminal device operates in the second mode (or Mode 2) mentioned above, when the upper layer is configured with congestion control, the PSSCH transmit power satisfies the following formula: PSSCH =min(P CMAX ,P MAX_CBR ,min(P PSSCH,D ,P PSSCH,SL ))[dBm];

[0146] Otherwise, the PSSCH transmit power satisfies the following formula P PSSCH =min(P CMAX ,min(P PSSCH,D ,P PSSCH,SL ))[dBm]

[0147] In the above formula, P CMAX Indicates the configured maximum transmit power, P MAX_CBR It represents the maximum sidelink transmit power determined by transmission priority and channel busy ratio (CBR) level under congestion control configured by the higher layer. PSSCH,D and P PSSCH,SL They represent the transmission power determined based on the downlink path loss and the transmission power determined based on the sidelink path loss, respectively.

[0148] P PSSCH,D and P PSSCH,SL Determined by the following formulas:

[0149] In the above formula, P 0,D / P 0,SL They represent the basic operating points of the transmit power based on downlink / sidelink path loss power control configured by the higher layer. D / α SL Indicates the downlink / sidelink path loss compensation factor configured by the upper layer. If the upper layer does not configure α D / α SL , then α D / α SL The value of can be 1. PL D / PL SL Indicates the downlink / sidelink path loss estimated by the terminal device. Indicates the number of PRBs occupied by PSSCH on symbols that do not carry PSCCH.

[0150] It should be noted that if the upper layer only configures P 0,D Without configuring P 0,SL , it means that power control is performed based only on the downlink path loss. In this case, min(P PSSCH,D ,PPSSCH,SL )=P PSSCH,D If the upper layer only configures P 0,SL Without configuring P 0,D , it means that power control is performed based only on the sidelink path loss. In this case, min(P PSSCH,D ,P PSSCH,SL )=P PSSCH,SL If the upper layer configures P 0,SL and P 0,D , it means that power control is performed based on both downlink path loss and sidelink path loss.

[0151] For symbols including both PSCCH and PSSCH, the terminal device can set the total transmission power P PSSCH The PRBs are allocated to PSCCH and PSSCH respectively according to the ratio of their PRB numbers.

[0152] For example, the transmission power P of PSSCH PSSCH2 satisfy:

[0153] In the above formula, Indicates the number of PRBs occupied by PSCCH.

[0154] Accordingly, the transmit power of PSCCH satisfies:

[0155] As described above, for a PSSCH transmission, the transmit power on each PSSCH resource element is consistent. The total transmit power distribution of the PSSCH for time-domain symbols including and excluding PSCCH is shown in Figure 17.

[0156] In a sideline communication system, PSCCH and PSSCH are transmitted in the same time slot, and the transmission granularity is one time slot. Therefore, during power control, if the transmit power of the current time slot is determined, the transmit power of each OFDM symbol in the current time slot is also determined, as shown in Figure 17.

[0157] The conventional transmission power shown in Figure 17 has a high requirement for transmission power, which will cause the terminal device to consume more electricity. Some terminal devices (such as weak-capability terminal devices) are usually difficult to meet the transmission power requirement. Alternatively, in order to meet the transmission power requirement, the use cost of the terminal device (such as weak-capability terminal device) will increase. However, if the transmission power of the side transmission is reduced, the coverage performance may be reduced (or the reception performance of the side data may be affected). Therefore, during the side data transmission process, how to ensure coverage performance while reducing the energy consumption of the terminal device is a problem that needs to be solved.

[0158] In order to solve the above problems, the embodiments of the present application are described in detail below.

[0159] Figure 18 is a flow chart of a sideline transmission method provided by one embodiment of the present application. Figure 18 is described from the perspective of a first terminal device, which can be any type of terminal device that supports sideline communication. In some implementations, the first terminal device can be a terminal device with weak capabilities. For example, the first terminal device can be a terminal device with high energy-saving performance requirements. In addition, the sideline transmission method shown in Figure 18 can be applied to both licensed and unlicensed spectrum.

[0160] Referring to Figure 18, in step S1810, the first terminal device repeatedly transmits the first side data in N consecutive time slots. The embodiment of the present application does not specifically limit the value of N. N can be a positive integer greater than 1. For example, the value of N is any value from 2 to 4. Of course, in special circumstances, the value of N can also be equal to 1. If N is equal to 1, similar to the related art, the first terminal device only transmits the first side data in a single time slot. The value of N can be determined based on one or more of the pre-configuration information, the configuration information of the network device, and the indication information of the second terminal device.

[0161] The first sidelink data may refer to a TB. That is, the first terminal device may repeatedly send the same TB in N consecutive time slots. The TB may be carried in a PSSCH. Therefore, the N consecutive time slots may transmit N PSSCHs, and the N PSSCHs carry the same TB.

[0162] The first terminal device may control the transmit power of N time slots (i.e., the power of the first terminal device when transmitting the first sidelink data or PSSCH in N time slots) so that the transmit power of each time slot in the N time slots is less than the first transmit power. The first transmit power may refer to the maximum transmit power currently available to the first terminal device. The first transmit power may be less than or equal to the maximum transmit power P allowed or configured by the first terminal device. CMAX Alternatively, the first transmission power may be the maximum transmission power P allowed or configured by the first terminal device. CMAX In the embodiment of the present application, a lower power is used to transmit the same sidelink data in each of N consecutive time slots, thereby saving energy consumption while ensuring coverage performance.

[0163] In some implementations, the first transmit power may be determined based on one or more of the following: a maximum transmit power P allowed or configured by the first terminal device; CMAX , the maximum sidelink transmit power P determined based on transmission priority and / or CBR MAX_CBR, the PSSCH transmission power P determined based on the downlink path loss PSSCH,D , the PSSCH transmission power P determined based on the side path loss PSSCH,SL .

[0164] For example, if the first terminal device operates in the second mode (or mode 2), when the upper layer configures congestion control, the first transmission power P PSSCH Satisfies the following formula: P PSSCH =min(P CMAX ,P MAX_CBR ,min(P PSSCH,D ,P PSSCH,SL ))[dBm];

[0165] Otherwise, the first transmission power P PSSCH Satisfies the following formula: P PSSCH =min(P CMAX ,min(P PSSCH,D ,P PSSCH,SL ))[dBm]

[0166] P PSSCH,D and P PSSCH,SL It can be determined by the following formula:

[0167] In the above formula, P 0,D / P 0,SL They represent the basic operating points of the transmit power based on downlink / sidelink path loss power control configured by the higher layer. D / α SL Indicates the downlink / sidelink path loss compensation factor configured by the upper layer. If the upper layer does not configure α D / α SL , then α D / α SL The value of can be 1. PL D / PL SL Indicates the downlink / sidelink path loss estimated by the terminal device. Indicates the number of PRBs occupied by PSSCH on symbols that do not carry PSCCH.

[0168] It should be noted that if the upper layer only configures P 0,D Without configuring P 0,SL , it means that power control is performed based only on the downlink path loss. In this case, min(P PSSCH,D ,P PSSCH,SL )=P PSSCH,D If the upper layer only configures P 0,SL Without configuring P 0,D, it means that power control is performed based only on the sidelink path loss. In this case, min(P PSSCH,D ,P PSSCH,SL )=P PSSCH,SL If the upper layer configures P 0,SL and P 0,D , it means that power control is performed based on both downlink path loss and sidelink path loss.

[0169] The embodiment of the present application does not specifically limit the method for determining the transmit power of each of the N time slots. In some implementations, the transmit power of each of the N time slots may be a fixed power, regardless of the value of N. The fixed power may be determined based on one or more of pre-configuration information, configuration information of the network device, and indication information of the second terminal device. In other implementations, the transmit power of each of the N time slots may be determined based on the number of time slots contained in the N time slots. For example, if N=2, the transmit power of each of the N time slots may be equal to 1 / 2 of the first transmit power. For another example, if N=4, the transmit power of each of the N time slots may be equal to 1 / 2, 1 / 3, or 1 / 4 of the first transmit power. Adjusting the transmit power of each time slot based on the number of N time slots helps to improve the flexibility of side power control.

[0170] The sum of the transmit powers of the N time slots can be greater than or equal to the first transmit power. If the sum of the transmit powers of the N time slots is equal to the first transmit power, it can also be understood that the first terminal device distributes the first transmit power to the N time slots according to a certain rule. These N time slots repeatedly transmit the first sidelink data, and the first transmit power is distributed to the N time slots. This not only reduces the transmit power requirement for each time slot, but also ensures coverage performance through repeated transmission.

[0171] The embodiments of the present application do not specifically limit the relationship between the transmit powers of the N time slots. The transmit powers of different time slots in the N time slots may be the same, different, or partially the same and partially different. The relationship between the transmit powers of different time slots in the N time slots will be described in more detail below, using examples in conjunction with Embodiments 1 and 2.

[0172] Example 1

[0173] In Example 1, the first terminal device configures the transmit power of different time slots in N time slots so that the transmit power of different time slots in the N time slots is equal. Setting the transmit power of the N time slots to the same transmit power can avoid the first terminal device from continuously adjusting the transmit power in a short period of time, thereby reducing the implementation complexity of the first terminal device.

[0174] In some implementations, the first transmit power may be evenly distributed to N consecutive time slots, such that the transmit power of each of the N time slots is 1 / N of the first transmit power. For example, assuming that the first transmit power is the maximum transmit power P allowed or configured by the first terminal device CMAX , then the first terminal device can CMAX Evenly distributed to N consecutive time slots. Therefore, the transmission power of each time slot in the N time slots is P CMAX -10logN. This implementation evenly distributes the first transmit power across N time slots and repeatedly transmits the same first sidelink data in each of the N time slots. Therefore, compared to related technologies, the total transmit power of the first sidelink data remains unchanged, and no additional transmit power increase is required, which is beneficial for energy conservation in the first terminal device.

[0175] In other implementations, in each of the N time slots, the transmit power of each time slot may be adjusted downward based on the first transmit power by a fixed power offset value. The fixed power offset value may be independent of the number of time slots. The fixed power offset value may be determined based on one or more of pre-configured information, configuration information of the network device, and indication information of the second terminal device.

[0176] As a more specific example, referring to FIG19 , if TB1 is transmitted in one time slot, the transmission power of a single time slot is P CMAX When TB1 is transmitted in two consecutive time slots (i.e., time slot 1-1 and time slot 1-2 in FIG19 ), the transmission power of each of the two consecutive time slots is P CMAX -10log2. That is, the transmission power of time slot 1-1 is half of that of time slot 1, and the transmission power of time slot 1-2 is also half of that of time slot 1.

[0177] Similarly, if TB2 is transmitted in one time slot, the transmission power of a single time slot is P CMAX When TB2 is transmitted in four consecutive time slots (i.e., time slot 2-1, time slot 2-2, time slot 2-3, and time slot 2-4 in FIG19 ), the transmission power of each of the four consecutive time slots is P CMAX -10log4. That is, the transmission power of time slot 2-1 is one-fourth of time slot 2, the transmission power of time slot 2-2 is one-fourth of time slot 2, the transmission power of time slot 2-3 is one-fourth of time slot 2, and the transmission power of time slot 2-4 is one-fourth of time slot 2.

[0178] Example 2: The transmit powers of N time slots are not completely the same

[0179] In the second embodiment, the transmit powers of the N time slots are not completely the same. For example, the transmit powers of different time slots of the N time slots are different. For another example, the transmit powers of some time slots of the N time slots are the same, while the transmit powers of some time slots are different.

[0180] In some implementations, the N time slots include X1 time slots and X2 time slots. X1 and X2 are both positive integers less than N. The sum of X1 and X2 can be less than N or equal to N. The transmit power of each time slot in the X1 time slots is the second transmit power, and the transmit power of each time slot in the X2 time slots is the third transmit power, and the second transmit power is greater than the third transmit power. That is, in the process of transmitting the first sidelink data through N consecutive time slots, the first terminal device sets the transmit power of X1 time slots in the N time slots to a higher transmit power (the second transmit power) to ensure that the transmit power of the X1 time slots can meet the requirements of the receiving performance. In addition, the first terminal device sets the transmit power of the remaining X2 time slots to a lower transmit power (the third transmit power) to reduce energy consumption. Although the transmit power of the X2 time slots is low, the first sidelink data in the X2 time slots can still be merged with the first sidelink data in the X1 time slot, thereby improving the coverage performance of the sidelink transmission.

[0181] The above-mentioned X1 time slots can be time slots at any position among the N time slots. In some implementations, the X1 time slots can be continuous X1 time slots among the N time slots. For example, the X1 time slots are the first X1 time slots among the N time slots. For another example, the X1 time slots are the last X1 time slots among the N time slots. For another example, the X1 time slots are time slots within the N time slots, that is, the X1 time slots do not include the first time slot and the last time slot among the N time slots. Setting the X1 time slots as continuous time slots can avoid the first terminal device from frequently adjusting the transmission power in a short period of time, thereby simplifying the implementation complexity of the first terminal device. Of course, the X1 time slots can also be discontinuous time slots among the N time slots.

[0182] As a more specific example, referring to FIG20 , if TB3 is transmitted in one time slot, the transmission power of the single time slot is P CMAX . If TB3 is transmitted through 8 consecutive time slots, the first terminal device can select X1 time slots from the 8 time slots, and each time slot in the X1 time slots adopts the second transmission power. For example, referring to Case 1 in Figure 20, the X1 time slots can be the first 3 consecutive time slots in the 8 time slots. For another example, referring to Case 2 in Figure 20, the X1 time slots can be the last 2 consecutive time slots in the 8 time slots. For another example, referring to Case 3 in Figure 20, the X1 time slots can be the four time slots of time slot 3-1, time slot 3-2, time slot 3-5, and time slot 3-7 selected from the 8 time slots according to certain criteria.

[0183] As mentioned above, the first terminal device transmits the first sidelink data at a higher second transmit power in X1 time slots. The embodiment of the present application does not specifically limit the method for determining the second transmit power. In some implementations, the first terminal device can reduce the transmit power of the X1 time slots by a fixed power offset value based on the first transmit power, and the reduced power is the second transmit power. The fixed power offset value can be determined based on one or more of pre-configured information, configuration information of the network device, and indication information of the second terminal device.

[0184] In some other implementations, the second transmit power may be 1 / K of the first transmit power (K ​​is a positive integer). The value of K may be a fixed value or may be selected from a range of values. For example, K is greater than or equal to X1, and K is less than or equal to N. The value of K may be determined based on one or more of pre-configured information, configuration information of the network device, and indication information of the second terminal device. For example, assuming that the first transmit power is P CMAX , then the second transmission power P2 can satisfy: P2 = P CMAX -Q, where Q is in the range [10logX1, 10logX1+1, 10logX1+2, …, 10logN]. If Q = 10logX1, the second transmit power is 1 / X1 of the first transmit power, i.e., K = X1. If Q = 10logX1+1, the second transmit power is 1 / (X1+1) of the first transmit power, i.e., K = X1+1. And so on.

[0185] As mentioned above, the first terminal device transmits the first sidelink data at a lower third transmit power in X2 time slots. The embodiment of the present application does not specifically limit the method for determining the third transmit power. In some implementations, the first terminal device may reduce the transmit power of X2 time slots by a fixed power offset value based on the first transmit power, and the reduced power is the third transmit power. The fixed power offset value may be determined based on one or more of pre-configured information, configuration information of the network device, and indication information of the second terminal device.

[0186] In other implementations, the third transmit power may be equal to 1 / X2 of the fourth transmit power, and the fourth transmit power may be determined based on the difference between the first transmit power and the second transmit power. For example, the fourth transmit power may be equal to the difference between the first transmit power and the second transmit power. In other words, the remaining power of the first transmit power, excluding the transmit power used in the X1 time slot, may be evenly distributed across the X2 time slots. This implementation ensures that the total transmit power of the N time slots remains equal to the first transmit power, without requiring additional transmit power, thereby facilitating energy conservation for the first terminal device.

[0187] As a more specific example, referring to FIG21, the first terminal device transmits TB3 in four consecutive time slots (i.e., time slot 3-1, time slot 3-2, time slot 3-3, and time slot 3-4 in FIG21). The transmission power of TB3 in time slot 3-1 and time slot 3-2 is a second transmission power P2, and the transmission power of TB3 in time slot 3-3 and time slot 3-4 is a third transmission power P3, and power P2>P3. The second transmission power P2=P CMAX -Q, where Q ranges from [10logX1, 10logX1+1, 10logX1+2, ..., 10logN]. In the example of FIG21 , X1=2, N=4. When Q=10logX1, the first terminal device transmits TB3 using the second transmission power P2 only in time slots 3-1 and 3-2. At this time, P2 is P CMAX When Q=10logN, the first terminal device transmits TB3 on time slots 3-1, 3-2, 3-3, and 3-4, and the transmission power of each time slot is P CMAX One quarter of the value of , and at this time P2=P3. When Q=[10logX1+1, 10logX1+2, ...], P2>P3.

[0188] The above description, in conjunction with Figures 18 to 21, describes in detail the sideline transmission method provided in the embodiment of the present application from the perspective of the transmitter. The following description, in conjunction with Figure 22, describes the sideline transmission method provided in the embodiment of the present application from the perspective of the receiver. It should be understood that the description of the transmitter corresponds to the description of the receiver. Therefore, for portions of the receiver not described in detail, reference can be made to the embodiments of the transmitter.

[0189] Figure 22 is a flow chart of a sideline transmission method provided by another embodiment of the present application. Figure 22 is described from the perspective of a second terminal device, which is a receiving device for the first sideline data. The second terminal device can be any type of terminal device that supports sideline communication. In some implementations, the second terminal device can be a terminal device with weak capabilities. For example, the second terminal device can be a terminal device with high energy-saving requirements. In addition, the sideline transmission method shown in Figure 22 can be applied to both licensed spectrum and unlicensed spectrum.

[0190] Referring to Figure 22, in step S2210, the second terminal device receives the first sideline data in S time slots out of N consecutive time slots. N time slots are used for repeated transmission of the first sideline data, where N is a positive integer greater than 1 and S is a positive integer less than or equal to N. If S is equal to N, it means that the second terminal device receives the first sideline data in all N time slots, which can maximize the reception reliability of the first sideline data. If S is less than N, it means that the second terminal device can select some time slots from the N time slots to receive the first sideline data, thereby reducing the merging complexity.

[0191] In some implementations, the S time slots are consecutive time slots. Receiving the first sidelink data in consecutive time slots can prevent the second terminal device from frequently switching between a receiving state and a non-receiving state in a short period of time, thereby simplifying the receiving operation of the second terminal device. Of course, in other implementations, the S time slots can also be discontinuous time slots.

[0192] In some implementations, after receiving the first sideline data in S time slots, the first terminal device may combine the first sideline data transmitted in the S time slots, thereby obtaining a reception combining gain.

[0193] In other implementations, after receiving the first sidelink data in S time slots, the second terminal device may merge the first sidelink data transmitted in L time slots of the S time slots (the L time slots may be consecutive time slots of the S time slots or non-consecutive time slots of the S time slots), where L is a positive integer less than S. The second terminal device selects some of the S time slots to merge the first sidelink data, which can reduce merging complexity.

[0194] It should be noted that the description of the transmit power of N time slots in the transmitting end embodiment also applies to the receiving end embodiment. For example, from the perspective of the receiving end, the receive power of each of the N time slots is also less than the first transmit power. The receive power of different time slots in the N time slots can be the same or different. To avoid redundancy, this description is not repeated here.

[0195] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 22. The device embodiment of the present application is described in detail below in conjunction with Figures 23 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.

[0196] Figure 23 is a schematic diagram of the structure of a terminal device provided by an embodiment of the present application. The terminal device 2300 shown in Figure 23 can be the first terminal device mentioned in any of the above embodiments. The terminal device 2300 includes a communication module 2310. The communication module 2310 is used to repeatedly transmit first sidelink data in N consecutive time slots, where the transmission power of each time slot in the N time slots is less than a first transmission power, and the first transmission power is less than or equal to the maximum transmission power allowed by the first terminal device, and N is a positive integer greater than 1.

[0197] In some implementations, the transmit powers of different time slots in the N time slots are equal.

[0198] In some implementations, the transmit power of each of the N time slots is 1 / N of the first transmit power.

[0199] In some implementations, the transmit powers of the N time slots are not exactly the same.

[0200] In some implementations, the N time slots include X1 time slots and X2 time slots, the transmission power of each time slot in the X1 time slots is the second transmission power, the transmission power of each time slot in the X2 time slots is the third transmission power, the second transmission power is greater than the third transmission power, and X1 and X2 are both positive integers less than N.

[0201] In some implementations, the X1 time slots are consecutive time slots.

[0202] In some implementations, the X1 time slots satisfy one of the following: the X1 time slots are the first X1 time slots among the N time slots, the X1 time slots are the last X1 time slots among the N time slots, and the X1 time slots do not include the first time slot and the last time slot among the N time slots.

[0203] In some implementations, the X1 time slots are discontinuous time slots.

[0204] In some implementations, the second transmit power is 1 / K of the first transmit power, where K is a positive integer.

[0205] In some implementations, K is greater than or equal to X1, and K is less than or equal to N.

[0206] In some implementations, the third transmit power is equal to 1 / X2 of the fourth transmit power, and the fourth transmit power is determined based on the difference between the first transmit power and the second transmit power.

[0207] In some implementations, the sum of the transmit powers of the N time slots is equal to the first transmit power.

[0208] In some implementations, the transmit power of each of the N time slots is determined based on the number of the N time slots.

[0209] In some implementations, the first transmit power is determined based on one or more of: the maximum transmit power allowed by the first terminal device, the transmit power of the PSSCH determined based on the downlink path loss, the transmit power of the PSSCH determined based on the sidelink path loss, and the maximum sidelink transmit power determined based on transmission priority and / or channel occupancy.

[0210] In some implementations, the first sidelink data is transmitted based on frequency domain resources in an unlicensed spectrum.

[0211] In some implementations, the first side row data is one TB.

[0212] Figure 24 is a schematic diagram of the structure of a terminal device provided in another embodiment of the present application. Terminal device 2400 shown in Figure 24 can be the second terminal device mentioned in any of the above embodiments. Terminal device 2400 includes a communication module 2410. Communication module 2410 is configured to receive first sidelink data in S time slots out of N consecutive time slots, wherein the N time slots are used for repeatedly transmitting the first sidelink data, where N is a positive integer greater than 1, and S is a positive integer less than or equal to N.

[0213] In some implementations, the S time slots are consecutive time slots; or, the S time slots are discontinuous time slots.

[0214] In some implementations, the terminal device 2500 further includes: a first merging module, configured to merge the first sidelink data transmitted in the S time slots.

[0215] In some implementations, the terminal device 2500 further includes: a second merging module, configured to merge the first sidelink data transmitted in L time slots out of the S time slots, where L is a positive integer less than S.

[0216] In some implementations, the L time slots are consecutive time slots; or, the L time slots are discontinuous time slots.

[0217] In some implementations, the first sidelink data is transmitted based on frequency domain resources in an unlicensed spectrum.

[0218] In some implementations, the first side row data is one TB.

[0219] Figure 25 is a schematic diagram of the structure of an apparatus according to an embodiment of the present application. The dotted lines in Figure 25 indicate that the unit or module is optional. Apparatus 2500 may be used to implement the method described in the above method embodiment. Apparatus 2500 may be a chip or a terminal device.

[0220] The device 2500 may include one or more processors 2510. The processor 2510 may support the device 2500 to implement the method described in the method embodiment above. The processor 2510 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.

[0221] The apparatus 2500 may further include one or more memories 2520. The memories 2520 store programs that can be executed by the processor 2510, causing the processor 2510 to perform the methods described in the above method embodiments. The memories 2520 may be independent of the processor 2510 or integrated into the processor 2510.

[0222] The apparatus 2500 may further include a transceiver 2530. The processor 2510 may communicate with other devices or chips via the transceiver 2530. For example, the processor 2510 may transmit and receive data with other devices or chips via the transceiver 2530.

[0223] The present invention also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal device provided in the present invention, and the program enables a computer to execute the method performed by the terminal device in each embodiment of the present invention.

[0224] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to the terminal device provided in the present application, and the program causes a computer to execute the method performed by the terminal device in each embodiment of the present application.

[0225] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal device provided in the embodiments of the present application, and the computer program enables a computer to execute the method executed by the terminal device in each embodiment of the present application.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] 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.

[0232] 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.

[0233] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0234] 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.

[0235] 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.

[0236] 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.

[0237] 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)).

[0238] 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 sidelink transmission method, characterized in that, Including: The first terminal device repeatedly transmits first sidelink data in N consecutive time slots, the transmission power of each of the N time slots being less than a first transmission power, the first transmission power being less than or equal to the maximum transmission power allowed by the first terminal device, and N being a positive integer greater than 1.

2. The method according to claim 1, characterized in that, The transmission powers of different time slots among the N time slots are equal.

3. The method according to claim 2, characterized in that, The transmission power of each of the N time slots is 1 / N of the first transmission power.

4. The method according to claim 1, characterized in that, The transmission powers of the N time slots are not all the same.

5. The method according to claim 4, characterized in that, The N time slots include X1 time slots and X2 time slots, the transmission power of each of the X1 time slots being a second transmission power, the transmission power of each of the X2 time slots being a third transmission power, the second transmission power being greater than the third transmission power, and both X1 and X2 being positive integers less than N.

6. The method according to claim 5, characterized in that, The X1 time slots are consecutive time slots.

7. The method according to claim 6, characterized in that, The X1 time slots satisfy one of the following: The X1 time slots are the first X1 time slots among the N time slots; The X1 time slots are the last X1 time slots among the N time slots; The X1 time slots do not include the first time slot and the last time slot among the N time slots.

8. The method according to claim 5, characterized in that, The X1 time slots are non-consecutive time slots.

9. The method according to any one of claims 5 to 8, characterized in that, The second transmission power is 1 / K of the first transmission power, where K is a positive integer.

10. The method according to claim 9, characterized in that, K is greater than or equal to X1 and less than or equal to N.

11. The method according to any one of claims 5 to 10, characterized in that, The third transmission power is equal to 1 / X2 of a fourth transmission power, and the fourth transmission power is determined based on the difference between the first transmission power and the second transmission power.

12. The method according to any one of claims 1 to 11, characterized in that, The sum of the transmission powers of the N time slots is equal to the first transmission power.

13. The method according to any one of claims 1 to 12, characterized in that, The transmission power of each of the N time slots is determined based on the number of the N time slots.

14. The method according to any one of claims 1 to 13, characterized in that, The first transmission power is determined based on one or more of the following: The maximum transmission power allowed by the first terminal device; The transmission power of the physical sidelink shared channel PSSCH determined based on the downlink path loss; The transmission power of the PSSCH determined based on the sidelink path loss; The maximum sidelink transmission power determined based on the transmission priority and / or the channel occupancy rate.

15. The method according to any one of claims 1 to 14, characterized in that, The first sidelink data is transmitted based on the frequency domain resources in the unlicensed spectrum.

16. The method according to any one of claims 1 to 15, characterized in that, The first sidelink data is one transmission block TB.

17. A sidelink transmission method, characterized in that, Including: The second terminal device receives the first sidelink data in S time slots among N consecutive time slots, the N time slots being used for repeatedly transmitting the first sidelink data, N being a positive integer greater than 1, and S being a positive integer less than or equal to N.

18. The method according to claim 17, characterized in that: The S time slots are consecutive time slots; or The S time slots are non-consecutive time slots.

19. The method according to claim 17 or 18, characterized in that, The method further includes: The second terminal device combines the first sidelink data transmitted in the S time slots.

20. The method according to claim 17 or 18, characterized in that, The method further includes: The second terminal device combines the first sidelink data transmitted in L time slots among the S time slots, L being a positive integer less than S.

21. The method according to claim 20, characterized in that: The L time slots are consecutive time slots; or The L time slots are non-consecutive time slots.

22. The method according to any one of claims 17 to 21, characterized in that, The first sidelink data is transmitted based on the frequency domain resources in the unlicensed spectrum.

23. The method according to any one of claims 17 to 22, characterized in that, The first sidelink data is one transmission block TB.

24. A terminal device, characterized in that, The terminal device is the first terminal device, and the terminal device includes: A communication module, configured to repeatedly transmit first sidelink data in N consecutive time slots, wherein the transmission power of each of the N time slots is less than a first transmission power, the first transmission power is less than or equal to the maximum transmission power allowed by the first terminal device, and N is a positive integer greater than 1.

25. The terminal device according to claim 24, characterized in that, The transmission powers of different time slots among the N time slots are equal.

26. The terminal device according to claim 25, characterized in that, The transmission power of each of the N time slots is 1 / N of the first transmission power.

27. The terminal device according to claim 24, characterized in that, The transmission powers of the N time slots are not all the same.

28. The terminal device according to claim 27, characterized in that, The N time slots include X1 time slots and X2 time slots, the transmission power of each of the X1 time slots is a second transmission power, the transmission power of each of the X2 time slots is a third transmission power, the second transmission power is greater than the third transmission power, and both X1 and X2 are positive integers less than N.

29. The terminal device according to claim 28, characterized in that, The X1 time slots are consecutive time slots.

30. The terminal device according to claim 29, characterized in that, The X1 time slots satisfy one of the following: The X1 time slots are the first X1 time slots among the N time slots; The X1 time slots are the last X1 time slots among the N time slots; The X1 time slots do not include the first time slot and the last time slot among the N time slots.

31. The terminal device according to claim 28, characterized in that, The X1 time slots are non-consecutive time slots.

32. The terminal device according to any one of claims 28 to 31, characterized in that, The second transmission power is 1 / K of the first transmission power, where K is a positive integer.

33. The terminal device according to claim 32, characterized in that, K is greater than or equal to X1 and less than or equal to N.

34. The terminal device according to any one of claims 28 to 33, characterized in that, The third transmission power is equal to 1 / X2 of a fourth transmission power, and the fourth transmission power is determined based on the difference between the first transmission power and the second transmission power.

35. The terminal device according to any one of claims 24 to 34, characterized in that, The sum of the transmission powers of the N time slots is equal to the first transmission power.

36. The terminal device according to any one of claims 24 to 35, characterized in that, The transmission power of each of the N time slots is determined based on the number of the N time slots.

37. The terminal device according to any one of claims 24 to 36, characterized in that, The first transmission power is determined based on one or more of the following: The maximum transmission power allowed by the first terminal device; The transmission power of the physical sidelink shared channel PSSCH determined based on the downlink path loss; The transmission power of the PSSCH determined based on the sidelink path loss; The maximum sidelink transmission power determined based on the transmission priority and / or channel occupancy rate.

38. The terminal device according to any one of claims 24 to 37, characterized in that, The first sidelink data is transmitted based on the frequency domain resources in the unlicensed spectrum.

39. The terminal device according to any one of claims 24 to 38, characterized in that, The first sidelink data is one transport block TB.

40. A terminal device, characterized in that, The terminal device is a second terminal device, and the terminal device includes: A communication module, configured to receive the first sidelink data in S time slots among N consecutive time slots, the N time slots being used to repeatedly transmit the first sidelink data, N is a positive integer greater than 1, and S is a positive integer less than or equal to N.

41. The terminal device according to claim 40, characterized in that: The S time slots are consecutive time slots; or, The S time slots are non-consecutive time slots.

42. The terminal device according to claim 40 or 41, characterized in that, The terminal device further includes: A first combining module, configured to combine the first sidelink data transmitted in the S time slots.

43. The terminal device according to claim 40 or 41, characterized in that, The terminal device further includes: A second combining module, configured to combine the first sidelink data transmitted in L time slots among the S time slots, where L is a positive integer less than S.

44. The terminal device according to claim 43, characterized in that: The L time slots are consecutive time slots; or, The L time slots are non-consecutive time slots.

52. The terminal device according to any one of claims 40 to 44, wherein The first sidelink data is transmitted based on the frequency domain resources in the unlicensed spectrum.

53. The terminal device according to any one of claims 40 to 45, wherein The first sidelink data is one transport block TB.

54. A terminal device, wherein It includes a transceiver, a memory, and a processor. The memory is used to store programs, and the processor is used to call the programs in the memory and control the transceiver to receive or send signals, so that the terminal executes the method described in any one of claims 1-16 or 17-23.

55. A device, wherein It includes a processor, which is used to call a program from a memory, so that the device executes the method described in any one of claims 1-16 or 17-23.

56. A chip, wherein It includes a processor, which is used to call a program from a memory, so that the device installed with the chip executes the method described in any one of claims 1-16 or 17-23.

57. A computer-readable storage medium, wherein A program is stored thereon, and the program causes a computer to execute the method described in any one of claims 1-16 or 17-23.

58. A computer program product, wherein It includes a program, and the program causes a computer to execute the method described in any one of claims 1-16 or 17-23.

59. A computer program, wherein The computer program causes a computer to execute the method described in any one of claims 1-16 or 17-23.

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