Sidelink transmission method and terminal devices

Abstract

Provided are a sidelink transmission method and terminal devices. The sidelink transmission method comprises: a terminal device sending first sidelink control information on a first carrier; and the terminal device sending, on a second carrier, a first sidelink positioning reference signal associated with the first sidelink control information. In the embodiments of the present application, different carriers are used to transmit sidelink control information and a sidelink positioning reference signal associated with the sidelink control information, thereby facilitating the mitigation of resource congestion.

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] In sidelink transmission scenarios, the sidelink positioning reference signal (SL-PRS) can be indicated / scheduled based on sidelink control information (SCI). Currently, resource congestion is prone to occur when transmitting SL-PRS. Therefore, how to alleviate resource congestion is a problem that needs to be solved.

[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 sidelink transmission method is provided, including: a terminal device sending first sidelink control information on a first carrier; and the terminal device sending a first sidelink positioning reference signal associated with the first sidelink control information on a second carrier.

[0006] In a second aspect, a terminal device is provided, including: a first sending unit, configured to send first sidelink control information on a first carrier; and a second sending unit, configured to send a first sidelink positioning reference signal associated with the first sidelink control information on a second carrier.

[0007] In a third 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 described in the first aspect.

[0008] In a fourth aspect, a device is provided, comprising a processor configured to call a program from a memory so that the device executes the method as described in the first aspect.

[0009] In a fifth aspect, a chip is provided, comprising a processor for calling a program from a memory so that a device equipped with the chip executes the method as described in the first aspect.

[0010] In a sixth 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 the first aspect.

[0011] In a seventh aspect, a computer program product is provided, comprising a program, wherein the program enables a computer to execute the method as described in the first aspect.

[0012] In an eighth aspect, a computer program is provided, which enables a computer to execute the method as described in the first aspect.

[0013] The embodiment of the present application uses different carriers to transmit sidelink control information and a sidelink positioning reference signal associated with the sidelink control information, thereby helping to alleviate resource congestion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] 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.

[0015] FIG2 is an example diagram of a side communication scenario within network coverage.

[0016] FIG3 is an example diagram of a side communication scenario with partial network coverage.

[0017] FIG4 is an example diagram of a side communication scenario outside network coverage.

[0018] FIG5 is a diagram showing an example of a side communication scenario based on a central control node.

[0019] FIG6 is an example diagram of a sideline communication method based on broadcasting.

[0020] FIG7 is an example diagram of a unicast-based sideline communication method.

[0021] FIG8 is an example diagram of a side communication method based on multicast.

[0022] FIG. 9A is a diagram illustrating an example of a time slot structure used by a sideline communication system.

[0023] FIG. 9B is another diagram illustrating an example of a time slot structure used by the sideline communication system.

[0024] 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).

[0025] FIG11 is a comparison diagram of the time slot structures corresponding to multiple transmissions of the PSSCH.

[0026] FIG12 is a diagram showing an example of mapping of a physical sidelink control channel (PSCCH) DM-RS.

[0027] FIG13 is a diagram showing an example of a time domain mapping method for PSSCH DM-RS.

[0028] FIG14 is a diagram showing an example of a frequency domain mapping method for PSSCH DM-RS.

[0029] FIG15 is a diagram illustrating an example of mapping of a channel state information reference signal (CSI-RS) in a sidelink.

[0030] FIG16 is an example diagram of the listen before talk (LBT) process.

[0031] FIG17 is a flow chart of the side transmission method provided in an embodiment of the present application.

[0032] FIG18 is an example diagram of a side positioning reference signal indication method provided by an embodiment of the present application.

[0033] FIG19 is an example diagram of a side positioning reference signal indication method provided by another embodiment of the present application.

[0034] FIG20 is an example diagram of a side positioning reference signal indication method provided in yet another embodiment of the present application.

[0035] FIG21 is an example diagram of a side positioning reference signal indication method provided in yet another embodiment of the present application.

[0036] Figure 22 is a structural diagram of the terminal device provided in an embodiment of the present application.

[0037] FIG23 is a schematic diagram of the structure of the device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] Communication system architecture

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] Sideline communication under different network coverage conditions

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Sideline communication based on central control node

[0055] 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.

[0056] Sideline communication mode

[0057] Some standards or protocols (such as the 3rd Generation Partnership Project (3GPP)) define two sideline communication modes: a first mode and a second mode.

[0058] 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.

[0059] 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.

[0060] Data transmission method of side communication

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] Time slot structure for sideline communication

[0066] 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.

[0067] 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}.

[0068] 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.

[0069] 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).

[0070] 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.

[0071] Sideways PSSCH

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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).

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] Sideways TBS

[0081] 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):

[0082] 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 R ′ E Indicates the number of reference REs that can be used for PSSCH in a PRB.

[0083] N R ′ E It can be determined based on the following formula (2):

[0084] 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 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.

[0085] Table 1: DM-RS patterns allowed in a resource pool The corresponding relationship

[0086] Sidelink DM-RS

[0087] 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.

[0088] The DM-RS sequence of PSCCH can be generated by formula (3):

[0089] 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):

[0090] 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. N ID ∈{0,1,…,65535}. In a resource pool, N ID The value can be configured or pre-configured by the network device.

[0091] 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.

[0092] Table 2: Number and position of DM-RS symbols in a time slot for different PSSCH and PSCCH symbol numbers

[0093] 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.

[0094] 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.

[0095] 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 ID The 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.

[0096] 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.

[0097] Side CSI-RS

[0098] 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:

[0099] 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.

[0100] Condition 2: Sidelink CSI reporting is activated through higher layer signaling.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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, b2, b1, b0] = [0, 0, 0, 1, 0, 0].

[0108] Unlicensed spectrum and channel monitoring

[0109] 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.

[0110] 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.

[0111] 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.

[0112] The following focuses on several different types of LBT methods (i.e., several different types of channel access methods).

[0113] 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.

[0114] Table 3 Channel access parameters corresponding to different channel priorities

[0115] 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.

[0116] 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).

[0117] 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.

[0118] 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.

[0119] 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.

[0120] Channel access for transmission(s) on multiple channels

[0121] When the system supports multiple channels (multiple RB sets), the terminal device needs to perform channel access on multiple channels separately, that is, LBT channel listening. When the downlink multi-channel access mechanism of the new radio unlicensed (NR-U) system is adopted, the terminal device can transmit on any channel to which the channel access is successful. In the sidelink over unlicensed (SL-U) system, for the transmission of PSFCH and sidelink synchronization signal block (S-SSB), the following multi-channel access methods are supported:

[0122] In type A multi-channel access, when the terminal device wants to send PSFCH or S-SSB on one or more channels (RB sets), the terminal device needs to perform type 1 channel access (type 1 LBT method) process independently on each of the one or more channels. If the access is successful on any one or more of the channels, the terminal device can then send PSFCH or S-SSB on this or more corresponding channels.

[0123] In Type B multi-channel access, when a terminal device wants to send PSFCH or S-SSB on one or more channels (RB sets), the terminal device randomly selects one channel from the one or more channels and uses Type 1 channel access. The remaining channels use Type 2 channel access (Type 2 LBT method). After Type 1 channel access is successful, the terminal device can send on the channel where Type 2 channel access is successful; if Type 1 channel access fails, then the channels using Type 2 channel access are considered unavailable.

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

[0125] In the new wireless 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] In the side transmission scenario, SL-PRS can be indicated / scheduled based on SCI. At present, resource congestion is very likely to occur when transmitting SL-PRS. The reason for resource congestion is mainly because SCI and the SL-PRS associated with SCI are transmitted through the same carrier. In other words, SL-PRS and service data will occupy the same carrier, which may cause the transmission within a carrier resource to be relatively busy. Especially in scenarios with a large number of users and a large number of positioning services and data services, carrier resource congestion may occur, and even signal transmission may be impossible. In addition, when SCI and SL-PRS are carried on the same carrier, transmission interference between SL-PRS and service data may also occur. Therefore, how to alleviate resource congestion is a problem that needs to be solved.

[0140] To address the above issues, the present embodiment of the present application carries the SCI and the SL-PRS associated with the SCI on different carriers for transmission. This cross-carrier positioning reference signal transmission method not only helps alleviate carrier resource congestion, but also helps avoid mutual interference between the SL-PRS and service data. The following describes the sideline communication method in the embodiment of the present application in conjunction with Figure 17.

[0141] Figure 17 is a schematic flowchart of a sideline communication method according to an embodiment of the present application. The terminal device mentioned in Figure 17 can be any type of terminal device that supports sideline communication, such as the terminal device 120 mentioned in Figure 1. The method shown in Figure 17 includes steps S1710 to S1720.

[0142] In step S1710, the terminal device sends a first SCI on a first carrier. The first carrier may also be referred to as a component carrier (CC). The first carrier may be a carrier corresponding to an unlicensed frequency band, or a carrier corresponding to an authorized frequency band or a dedicated frequency band. Using a carrier corresponding to the authorized frequency band or the dedicated frequency band (such as an intelligent traffic system (ITS) frequency band) to transmit the first SCI, a key signaling, helps improve the transmission reliability of the SCI.

[0143] The first SCI may refer to any type of SCI associated with the first SL-PRS. For example, the first SCI may be a first-order SCI, or the first SCI may be a second-order SCI. It should be understood that the association of the first SCI with the first SL-PRS may mean that the first SCI indicates or schedules the first SL-PRS.

[0144] In step S1720 , the terminal device sends a first SL-PRS associated with a first SCI on a second carrier.

[0145] The second carrier refers to another carrier that is different from the first carrier. The second carrier can be a carrier corresponding to an authorized frequency band, or a carrier corresponding to an unlicensed frequency band (also referred to as an unlicensed frequency band or a shared frequency band). In other words, the first SL-PRS can be transmitted through an authorized frequency band, or through an unlicensed frequency band. The bandwidth of the unlicensed frequency band is larger, and transmitting the SL-PRS based on the unlicensed frequency band helps to improve the accuracy of side positioning.

[0146] According to the above content, the implementation of this application mainly utilizes different carriers to transmit the first SL-PRS and the first SCI associated with it. This cross-carrier positioning reference signal transmission method not only helps to alleviate the congestion of carrier resources, but also helps to avoid mutual interference between SL-PRS and business data.

[0147] It should be noted that the embodiment of the present application does not specifically limit the method for determining the resource location of the first SL-PRS in the second carrier (which may include the time domain resource location and / or the frequency domain resource location). For example, it can be determined by one or more of the following methods: protocol pre-definition, network device configuration, pre-configuration, etc. In some implementations, the resource location of the first SL-PRS may be based on the first SCI indication. It should be understood that the first SCI may explicitly indicate the resource location of the first SL-PRS, or may implicitly indicate the resource location of the first SL-PRS. Two possible indication methods are given below.

[0148] Implementation method 1: explicit instruction

[0149] For example, the first SCI may include one or more information fields. The one or more information fields may be used to indicate the resource location of the first SL-PRS.

[0150] In some implementations, the one or more information fields described above may be used to indicate one or more of the following: the second carrier; the time slot in which the first SL-PRS is located; the frequency domain position of the first SL-PRS in the second carrier; the type of comb structure used by the first SL-PRS in the frequency domain; and the offset of the resource element corresponding to the comb structure.

[0151] For example, the first SCI may include a first information field. The first information field may include 0 to N1 bits (N1 is a positive integer greater than or equal to 1). If the value of the first information field is 0 bits, it indicates that the first SCI does not include the first information field. The first information field may indicate the second carrier. For example, the first information field may indicate the index of the second carrier.

[0152] For another example, the first SCI may include a second information field. The second information field may include 0 to N2 bits (N2 is a positive integer greater than or equal to 1). If the value of the second information field is 0 bits, it means that the first SCI does not include the second information field. The second information field may indicate the time slot where the first SL-PRS is located. For example, the second information field may indicate the index of the time slot where the first SL-PRS is located.

[0153] For another example, the first SCI may include a third information field. The third information field may include 0 to N3 bits (N3 is a positive integer greater than or equal to 1). If the value of the third information field is 0 bits, it indicates that the first SCI does not include the third information field. The third information field may indicate the frequency domain position of the first SL-PRS in the second carrier.

[0154] In some implementations, the frequency domain position of the first SL-PRS in the second carrier includes information such as the set of resource blocks occupied by the first SL-PRS, the comb-tooth resource blocks (comb-tooth structured resource blocks) or interleaved resource blocks (interleaved structured resource blocks) occupied by the first SL-PRS.

[0155] That is, the third information field may indicate the set of resource blocks occupied by the first SL-PRS in the second carrier, and / or the third information field may indicate the comb-tooth resource blocks or interleaved resource blocks occupied by the first SL-PRS on the resource block set. For example, the third information field may indicate the index of the set of resource blocks occupied by the first SL-PRS in the second carrier, and / or the third information field may indicate the index of the comb-tooth resource blocks or interleaved resource blocks occupied by the first SL-PRS on the resource block set.

[0156] In some implementations, the resource block set occupied by the first SL-PRS in the second carrier may refer to part or all of the resource blocks of one or more resource block sets occupied by the first SL-PRS in the second carrier. For example, the above-mentioned third information field may indicate that the first SL-PRS occupies part or all of the resource blocks in resource block set 1, and the third information field may also indicate that the first SL-PRS occupies part or all of the resource blocks in resource block set 2 and resource block set 3. It should be understood that the frequency domain resources in the second carrier may include multiple resource block sets, and the multiple resource block sets may include, for example, resource block set 1, resource block set 2, and resource block set 3.

[0157] For another example, the first SCI may include a fourth information field. The fourth information field may include 0 to N4 bits (N4 is a positive integer greater than or equal to 1). If the value of the fourth information field is 0 bits, it means that the first SCI does not include the fourth information field. The fourth information field may indicate the type of comb structure used by the first SL-PRS in the frequency domain. For example, the fourth information field may indicate that the comb structure used by the first SL-PRS in the frequency domain is comb-4 (a first SL-PRS resource element appears every 4 REs).

[0158] For another example, the first SCI may include a fifth information field. The fifth information field may include 0 to N5 bits (N5 is a positive integer greater than or equal to 1). If the value of the fifth information field is 0 bits, it means that the first SCI does not include the fifth information field. The fifth information field may indicate the offset of the resource element corresponding to the above-mentioned comb structure. For example, the fifth information field may indicate that the offset of the resource element corresponding to the above-mentioned comb structure is 0 (that is, the starting position of the first SL-PRS resource element in the first OFDM symbol in the resource set occupied by the first SL-PRS is 0 based on the offset of the lowest RE in the frequency domain occupied by the current time slot).

[0159] Implementation 1 is described in more detail below with reference to specific examples. It should be noted that the example of FIG. 18 is merely intended to help those skilled in the art understand the embodiments of the present application, and is not intended to limit the embodiments of the present application to the specific numerical values ​​or specific scenarios illustrated. Those skilled in the art can obviously make various equivalent modifications or changes based on the example of FIG. 18, and such modifications or changes also fall within the scope of the embodiments of the present application.

[0160] As shown in Figure 18, SCI (first CCI) can be sent in time slot n on carrier CC1 (such as the first carrier), and the SCI can be used to indicate / schedule SL-PRS (such as the first SL-PRS) to be sent in time slot n on carrier CC2 (such as the second carrier).

[0161] Time slot n of carrier CC1 includes four SCIs (e.g., SCI1, SCI2, SCI3, and SCI4). These four SCIs can be used to indicate or schedule the four SL-PRS signals (e.g., SL-PRS1, SL-PRS2, SL-PRS3, and SL-PRS4) in time slot n of carrier CC2 (e.g., the second carrier). The sidelink positioning reference signals SL-PRS1, SL-PRS2, SL-PRS3, and SL-PRS4 in time slot n of CC2 respectively occupy four SL-PRS resource block sets (SL-PRS resource block set 1, SL-PRS resource block set 2, SL-PRS resource block set 3, and SL-PRS resource block set 4) on CC2. Each resource block set occupied by the SL-PRS corresponds to an independent comb structure type.

[0162] Continuing to refer to Figure 18, SCI1 can be used to indicate or schedule SL-PRS1. SCI1 can be used to indicate at least one of the following: the carrier CC2 where SL-PRS1 is located, the time slot index n where SL-PRS1 is located, the SL-PRS resource set 1 of SL-PRS1 in time slot n, the comb structure type used by SL-PRS1 in the frequency domain is comb-4 (one SL-PRS1 resource element appears every 4 REs), and the offset of the comb structure type is 0 (that is, the starting position of the first SL-PRSRE in the first OFDM symbol in the SL-PRS resource set 1 is based on the offset of the lowest RE in the frequency domain occupied by the current time slot n is 0).

[0163] SCI2 can be used to indicate or schedule SL-PRS2. SCI2 can be used to indicate at least one of the following: carrier CC2 where SL-PRS2 is located, time slot index n where SL-PRS2 is located, SL-PRS resource set 2 of SL-PRS2 in time slot n, the comb structure type used by SL-PRS2 in the frequency domain is comb-4, and the offset of the comb structure type is 2 (that is, the starting position of the first SL-PRSRE in the first OFDM symbol in SL-PRS resource set 2 is based on the offset of the lowest RE in the frequency domain occupied by the current time slot n is 2).

[0164] Similarly, SCI3 can be used to indicate or schedule SL-PRS3, and SCI4 can be used to indicate or schedule SL-PRS4, which is similar to the way SCI1 indicates or schedules SL-PRS1, and will not be described in detail here.

[0165] It should be noted that, in the above explicit indication method, the first SCI and the first SL-PRS may be located in the same time slot. Of course, the first SCI and the first SL-PRS may also be located in different time slots. This application does not impose any specific restrictions on this.

[0166] Implementation method 2: Implicit indication

[0167] In implementation method two, the resource location of the first SL-PRS can be determined based on the resource location of the first SCI. In other words, the resource location of the first SL-PRS is associated with the resource location of the first SCI. The association can be determined based on protocol pre-definition, network device configuration or pre-configuration, etc. It should be understood that the resource location of the first SL-PRS may include the time domain resource information and / or frequency domain resource information occupied by the first SL-PRS on the second carrier. The time domain resource information may, for example, include the OFDM symbol occupied by the first SL-PRS on the second carrier. The frequency domain resource information may, for example, include the set of frequency domain resources occupied by the first SL-PRS on the second carrier, the type of comb structure of the frequency domain resources used by the first SCI on the second carrier, etc.

[0168] There are various ways to establish an association between the resource location of the first SL-PRS and the resource location of the first SCI. For example, the resource location of the first SL-PRS can be determined based on the resource location of the first SCI using a preset time domain and / or frequency domain offset. In another example, an association can be established between a first index corresponding to the resource location of the first SL-PRS and a second index corresponding to the resource location of the first SCI.

[0169] The first index may refer to the index of the resource location itself (such as the index of the resource location of the first SCI on the first carrier), or may refer to other indexes that can determine the resource location, such as the index of the subchannel where the first SL-PRS is located.

[0170] In some implementations, the resource position corresponding to the second index includes one or more of the following: a resource position in the first time slot; a resource position in the second time slot; wherein the first time slot is the time slot where the first SCI is located, and the second time slot is later than the first time slot in the time domain. That is, the resource position of the first SCI and the resource position of the first SL-PRS may be located in the same time slot or in different time slots. For example, when the resource position corresponding to the second index is the resource position in the first time slot (e.g., time slot n), the resource position of the first SCI and the resource position of the first SL-PRS are located in the same time slot. For another example, when the resource position corresponding to the second index is the resource position in the second time slot (e.g., time slot n+1), the resource position of the first SCI and the resource position of the first SL-PRS are located in different time slots.

[0171] In an embodiment of the present application, the first SL-PRS is indicated or scheduled across time slots, making the transmission of the first SL-PRS more flexible, and can also make full use of sporadic OFDM symbols on different time slots, which helps to improve resource utilization.

[0172] In some implementations, the index of the resource location of the first SL-PRS on the second carrier may be determined based on the index of the starting subchannel corresponding to the first SCI on the first carrier. It should be understood that the starting subchannel may refer to the subchannel with the lowest frequency domain position among the subchannels corresponding to the first SCI.

[0173] In some implementations, the resource location of the first SL-PRS on the second carrier may include but is not limited to one or more of the following: an index of the resource location of the first SL-PRS on the second carrier; an index of the subchannel where the first SL-PRS is located; the type of comb structure of the frequency domain resources used by the first SL-PRS on the second carrier; and the OFDM symbol occupied by the first SL-PRS in the time domain of the second carrier.

[0174] The following describes implementation method 2 in more detail with reference to specific examples. It should be noted that the examples in Figures 19 to 21 are merely intended to help those skilled in the art understand the embodiments of the present application, and are not intended to limit the embodiments of the present application to the specific numerical values ​​or specific scenarios illustrated. Those skilled in the art can obviously make various equivalent modifications or changes based on the examples of Figures 19 to 21 given, and such modifications or changes also fall within the scope of the embodiments of the present application.

[0175] As mentioned above, the index of the resource location of the first SL-PRS can be determined based on the index of the resource location of the first SCI. The following is a more detailed example of this implicit indication method in conjunction with Figure 19. Figure 19 is an example diagram of an implicit indication method of a sidelink positioning reference signal provided in an embodiment of the present application.

[0176] As shown in Figure 19, in time slot n of carrier CC1 (such as the first carrier), the resource position of SCI can include 7 frequency domain resource positions, and the 7 resource positions respectively correspond to different SL-PRS resource positions in time slot n of carrier CC2 (such as the second carrier) and information such as the comb structure type used by the SL-PRS in the frequency domain.

[0177] For example, SCI1 occupies resource position 1 on CC1, then the resource position 1 occupied by SCI1 may correspond to the SL-PRS resource position 1 occupied by SL-PRS1 on CC2, and the comb structure type used by the SL-PRS1 in the frequency domain is comb-4 (one SL-PRS1 resource element appears every 4 REs).

[0178] For example, SCI4 occupies resource position 7 on CC1, then resource position 7 occupied by SCI4 may correspond to SL-PRS resource position 4 occupied by SL-PRS4 on CC2, and the comb structure type used by SL-PRS4 in the frequency domain is comb-4.

[0179] As mentioned above, the first SL-PRS can be used to indicate the resource location of the first SCI on the second carrier across time slots. That is, the resource location of the first SCI and the resource location of the first SL-PRS can be located in different time slots. This implicit indication method is described in more detail below with reference to Figure 20. Figure 20 is an example diagram of an implicit indication method for a sidelink positioning reference signal provided in another embodiment of the present application.

[0180] As shown in FIG20 , in time slot n of carrier CC1 (eg, the first carrier), the resource positions of the SCI may include 14 frequency domain resource positions.

[0181] For example, if SCI (such as the first SCI) occupies resource position 8 on CC1, then resource position 8 occupied by SCI may correspond to SL-PRS resource position 1 of SL-PRS (such as the first SL-PRS) in time slot n+1 of carrier CC2 (such as the second carrier).

[0182] For another example, if the SCI occupies resource position 10 on CC1, then the resource position 10 occupied by the SCI may correspond to the SL-PRS resource position 2 in the time slot n+1 of the carrier CC2.

[0183] As mentioned above, the index of the resource location of the first SL-PRS on the second carrier can be determined based on the index of the starting subchannel corresponding to the first SCI on the first carrier. This implicit indication method is described in more detail below with reference to Figure 21. Figure 21 is an example diagram of an implicit indication method for a sidelink positioning reference signal provided in another embodiment of the present application.

[0184] As shown in Figure 21, the index of the starting subchannel corresponding to the first SCI on the first carrier can be used to indicate or schedule the index of the resource position of the first SL-PRS on the second carrier, the type of comb structure of frequency domain resources used by the first SCI on the second carrier, and the OFDM symbol occupied by the first SCI in the time domain of the second carrier.

[0185] The time slot n of carrier CC1 (such as the first carrier) includes 4 SCIs (such as SCI1, SCI2, SCI3 and SCI4), and the starting subchannels corresponding to the 4 SCIs in the frequency domain of CC1 are subchannel 1, subchannel 5, subchannel 8 and subchannel 11 respectively.

[0186] For example, the frequency domain starting position of SCI1 on CC1 is subchannel 1, which can be used to indicate or schedule the SL-PRS resource position index occupied by SL-PRS1 on time slot n of CC2 (such as the second carrier) is 1, and the comb structure of the frequency domain resources used by SL-PRS1 on CC2 is comb-4 (one SL-PRS1 resource element appears every 4 REs).

[0187] The frequency domain starting position of SCI2 on CC1 is subchannel 5, which can be used to indicate or schedule the SL-PRS resource position index occupied by SL-PRS2 on time slot n of CC2 as 2, and the comb structure of the frequency domain resources used by SL-PRS2 on CC2 is comb-4.

[0188] The frequency domain starting position of SCI3 on ​​CC1 is subchannel 8, which can be used to indicate or schedule the SL-PRS resource position index occupied by SL-PRS3 on time slot n of CC2 is 3, the comb structure of the frequency domain resources used by SL-PRS3 on CC2 is comb-2 (one SL-PRS3 resource element appears every 2 REs), and SL-PRS3 occupies 4 OFDM symbols on CC2.

[0189] The frequency domain starting position of SCI4 on CC1 is subchannel 11, which can be used to indicate or schedule the SL-PRS resource position index occupied by SL-PRS4 on time slot n of CC2 is 4, the comb structure of the frequency domain resources used by SL-PRS4 on CC2 is comb-2, and SL-PRS4 occupies 2 OFDM symbols on CC2.

[0190] According to the above description, it can be seen that the embodiment of the present application can utilize the reliability of authorized spectrum / dedicated spectrum resources to transmit SCI, a key signaling, and at the same time utilize unauthorized spectrum to transmit SL-PRS, thereby ensuring the high accuracy requirements of side positioning through large bandwidth.

[0191] The SCI in this solution can explicitly or implicitly indicate the time-frequency resource location of SL-PRS on different component carriers (such as the second carrier) in a cross-carrier case, which greatly improves the flexibility and reliability of SCI indication, while saving time-frequency resources on the authorized spectrum / dedicated spectrum, so that more time-frequency resources are available on the authorized spectrum / dedicated spectrum for transmitting business data.

[0192] In addition, transmitting a large number of SL-PRS on unlicensed spectrum is conducive to separately transmitting two types of data, SL-PRS and business data, through different carriers, thereby avoiding mutual interference between the two types of data and improving resource utilization efficiency.

[0193] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 21. The device embodiment of the present application is described in detail below in conjunction with Figures 22 to 23. 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.

[0194] Figure 22 is a schematic diagram of a terminal device according to an embodiment of the present application. The terminal device 2100 shown in Figure 22 includes: a first sending unit 2210 and a second sending unit 2220.

[0195] The first sending unit 2210 is configured to send first sidelink control information on a first carrier.

[0196] The second sending unit 2220 is configured to send, on a second carrier, a first sidelink positioning reference signal associated with the first sidelink control information.

[0197] In some implementations, the first carrier is a carrier corresponding to an authorized frequency band or a dedicated frequency band.

[0198] In some implementations, the second carrier is a carrier corresponding to an unlicensed frequency band.

[0199] In some implementations, the first sidelink control information includes one or more information fields, where the one or more information fields are used to indicate a resource location of the first sidelink positioning reference signal.

[0200] In some implementations, the one or more information fields are used to indicate one or more of the following: the second carrier; the time slot in which the first sidelink positioning reference signal is located; the frequency domain position of the first sidelink positioning reference signal in the second carrier; the type of comb structure used by the first sidelink positioning reference signal in the frequency domain; and the offset of the resource element corresponding to the comb structure.

[0201] In some implementations, the frequency domain position of the first sidelink positioning reference signal in the second carrier includes one or more of the following: a set of resource blocks occupied by the first sidelink positioning reference signal; and a comb-tooth resource block occupied by the first sidelink positioning reference signal.

[0202] In some implementations, a resource location of the first sidelink positioning reference signal is determined based on a resource location of the first sidelink control information.

[0203] In some implementations, the resource location occupied by the first sidelink control information corresponds to a first index, the resource location occupied by the first sidelink positioning reference signal corresponds to a second index, and the second index is determined based on the first index.

[0204] In some implementations, the resource location corresponding to the second index includes one or more of the following: a resource location in a first time slot; a resource location in a second time slot; wherein the first time slot is the time slot where the first side control information is located, and the second time slot is later than the first time slot in the time domain.

[0205] In some implementations, the first index is determined based on one or more of: an index of a resource location occupied by the first sidelink control information; and an index of a first subchannel corresponding to the first sidelink control information.

[0206] In some implementations, the first subchannel is a subchannel with the lowest frequency domain position among the subchannels corresponding to the first sidelink control information.

[0207] In some implementations, the first sidelink control information and the first sidelink positioning reference signal are located in the same time slot; or, the first sidelink control information and the first sidelink positioning reference signal are located in different time slots.

[0208] In some implementations, the first sidelink control information is used to indicate or schedule the first sidelink positioning reference signal.

[0209] Figure 23 is a schematic diagram of the structure of an apparatus according to an embodiment of the present application. The dotted lines in Figure 23 indicate that the unit or module is optional. Apparatus 2300 may be used to implement the method described in the above method embodiment. Apparatus 2300 may be a chip or a terminal device.

[0210] The device 2300 may include one or more processors 2310. The processor 2310 may support the device 2300 to implement the method described in the above method embodiment. The processor 2310 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.

[0211] The apparatus 2300 may further include one or more memories 2320. The memories 2320 store programs that can be executed by the processor 2310, causing the processor 2310 to perform the methods described in the above method embodiments. The memories 2320 may be independent of the processor 2310 or integrated into the processor 2310.

[0212] The apparatus 2300 may further include a transceiver 2330. The processor 2310 may communicate with other devices or chips via the transceiver 2330. For example, the processor 2310 may transmit and receive data with other devices or chips via the transceiver 2330.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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)).

[0228] 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 terminal device sends first sidelink control information on a first carrier; The terminal device sends a first sidelink positioning reference signal associated with the first sidelink control information on a second carrier.

2. The method according to claim 1, wherein The first carrier is a carrier corresponding to an authorized frequency band or a dedicated frequency band.

3. The method according to claim 1 or 2, characterized in that, The second carrier is a carrier corresponding to an unlicensed frequency band.

4. The method according to any one of claims 1 to 3, characterized in that, The first sidelink control information includes one or more information fields, and the one or more information fields are used to indicate the resource location of the first sidelink positioning reference signal.

5. The method according to claim 4, wherein The one or more information fields are used to indicate one or more of the following: The second carrier; The time slot where the first sidelink positioning reference signal is located; The frequency-domain position of the first sidelink positioning reference signal in the second carrier; The type of comb structure used by the first sidelink positioning reference signal in the frequency domain; The offset of the resource element corresponding to the comb structure.

6. The method according to claim 5, wherein The frequency-domain position of the first sidelink positioning reference signal in the second carrier includes one or more of the following: The set of resource blocks occupied by the first sidelink positioning reference signal; The comb-shaped resource blocks occupied by the first sidelink positioning reference signal.

7. The method according to any one of claims 1 to 3, characterized in that The resource location of the first sidelink positioning reference signal is determined based on the resource location of the first sidelink control information.

8. The method according to claim 7, wherein The resource location occupied by the first sidelink control information corresponds to a first index, and the resource location occupied by the first sidelink positioning reference signal corresponds to a second index, and the second index is determined based on the first index.

9. The method according to claim 8, characterized in that, The resource location corresponding to the second index includes one or more of the following: The resource location in the first time slot; The resource location in the second time slot; Wherein, the first time slot is the time slot where the first sidelink control information is located, and the second time slot is later than the first time slot in the time domain.

10. The method according to claim 8 or 9, characterized in that, The first index is determined based on one or more of the following: The index of the resource location occupied by the first sidelink control information; The index of the first subchannel corresponding to the first sidelink control information.

11. The method according to claim 10, wherein The first subchannel is the subchannel with the lowest frequency-domain position in the subchannels corresponding to the first sidelink control information.

12. The method according to any one of claims 1 to 11, wherein: The first sidelink control information and the first sidelink positioning reference signal are in the same time slot; or, The first sidelink control information and the first sidelink positioning reference signal are in different time slots.

13. The method according to any one of claims 1 to 12, characterized in that The first sidelink control information is used to indicate or schedule the first sidelink positioning reference signal.

14. A terminal device, characterized in that, Including: A first sending unit, configured to send first sidelink control information on a first carrier; A second sending unit, configured to send a first sidelink positioning reference signal associated with the first sidelink control information on a second carrier.

15. The terminal device according to claim 14, wherein The first carrier is a carrier corresponding to an authorized frequency band or a dedicated frequency band.

16. The terminal device according to claim 14 or 15, characterized in that, The second carrier is a carrier corresponding to an unlicensed frequency band.

17. The terminal device according to any one of claims 14 to 16, characterized in that, The first sidelink control information includes one or more information fields, and the one or more information fields are used to indicate the resource location of the first sidelink positioning reference signal.

18. The terminal device according to claim 17, wherein The one or more information fields are used to indicate one or more of the following: The second carrier; The time slot where the first sidelink positioning reference signal is located; The frequency-domain position of the first sidelink positioning reference signal in the second carrier; The type of comb structure used by the first sidelink positioning reference signal in the frequency domain; The offset of the resource element corresponding to the comb structure.

19. The terminal device according to claim 18, wherein The frequency-domain position of the first sidelink positioning reference signal in the second carrier includes one or more of the following: The set of resource blocks occupied by the first sidelink positioning reference signal; The comb resource blocks occupied by the first sidelink positioning reference signal.

20. The terminal device according to any one of claims 14 to 16, characterized in that The resource position of the first sidelink positioning reference signal is determined based on the resource position of the first sidelink control information.

21. The terminal device according to claim 20, wherein The resource position occupied by the first sidelink control information corresponds to a first index, and the resource position occupied by the first sidelink positioning reference signal corresponds to a second index, and the second index is determined based on the first index.

22. The terminal device according to claim 21, wherein, The resource position corresponding to the second index includes one or more of the following: The resource position in the first time slot; The resource position in the second time slot; Wherein, the first time slot is the time slot where the first sidelink control information is located, and the second time slot is later than the first time slot in the time domain.

23. The terminal device according to claim 21 or 22, characterized in that, The first index is determined based on one or more of the following: The index of the resource position occupied by the first sidelink control information; The index of the first subchannel corresponding to the first sidelink control information.

24. The terminal device according to claim 23, wherein The first subchannel is the subchannel with the lowest frequency-domain position in the subchannels corresponding to the first sidelink control information.

25. The terminal device according to any one of claims 14 to 24, characterized in that: The first sidelink control information and the first sidelink positioning reference signal are in the same time slot; or, The first sidelink control information and the first sidelink positioning reference signal are in different time slots.

26. The terminal device according to any one of claims 14 to 25, characterized in that, The first sidelink control information is used to indicate or schedule the first sidelink positioning reference signal.

27. A terminal device, characterized in that, Comprising a transceiver, a memory and a processor, the memory is used to store a program, and the processor is used to call the program in the memory and control the transceiver to receive or send signals, so that the terminal executes the method according to any one of claims 1-13.

28. A device, characterized in that, Comprising a processor, configured to call a program from a memory, so that the device executes the method according to any one of claims 1-13.

29. A chip, characterized in that, Comprising a processor, configured to call a program from a memory, so that the device installed with the chip executes the method according to any one of claims 1-13.

30. A computer-readable storage medium, characterized in that, A program is stored thereon, and the program causes a computer to execute the method according to any one of claims 1-13.

31. A computer program product, characterized in that, Comprising a program, and the program causes a computer to execute the method according to any one of claims 1-13.

32. A computer program, characterized in that, The computer program causes a computer to execute the method according to any one of claims 1-13.

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