Resource selection method and device, equipment and storage medium

Abstract

The invention discloses a resource selection method and device, equipment and a storage medium, and relates to the technical field of communication. The method comprises selecting at least one SL PRS resource from a set of SL PRS resources, the SL PRS resource for transmitting the SL PRS (910). According to the embodiment of the invention, the terminal device selects at least one SL PRS resource from the SL PRS resource set, and the number of candidate resources in the SL PRS resource set is large, so that resource collision or mutual interference with other terminal devices can be effectively reduced.

Description

Resource selection method, device, equipment and storage medium Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular to a resource selection method, apparatus, device, and storage medium. Background Art

[0002] In the NR SL (New Radio SideLink) system, how the terminal device should select the SL PRS (SL Positioning Reference Signal) resource after performing resource exclusion requires further discussion and research.

[0003] Summary of the Invention

[0004] The present invention provides a resource selection method, apparatus, device, and storage medium. The technical solution is as follows:

[0005] According to one aspect of an embodiment of the present application, a resource selection method is provided, the method being executed by a terminal device, the method comprising:

[0006] At least one SL PRS resource is selected from the SL PRS resource set, where the SL PRS resource is used to send the SL PRS.

[0007] According to one aspect of an embodiment of the present application, a resource selection device is provided, the device comprising:

[0008] The selection module is configured to select at least one SL PRS resource from a SL PRS resource set, where the SL PRS resource is used to send the SL PRS.

[0009] According to one aspect of an embodiment of the present application, a terminal device is provided, comprising a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program to implement the above-mentioned resource selection method.

[0010] According to one aspect of an embodiment of the present application, a computer-readable storage medium is provided, in which a computer program is stored. The computer program is configured to be executed by a processor to implement the above-mentioned resource selection method.

[0011] According to one aspect of an embodiment of the present application, a chip is provided, which includes a programmable logic circuit and / or program instructions, and when the chip is running, is used to implement the above-mentioned resource selection method.

[0012] According to one aspect of an embodiment of the present application, a computer program product is provided, which includes a computer program stored in a computer-readable storage medium. A processor reads and executes the computer program from the computer-readable storage medium to implement the above-mentioned resource selection method.

[0013] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0014] By selecting at least one SL PRS resource from the SL PRS resource set by the terminal device, the number of candidate resources in the SL PRS resource set is large, which can effectively reduce resource collision or mutual interference with other terminal devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG1 is a schematic diagram of a network architecture provided by an embodiment of the present application;

[0016] FIG2 is a schematic diagram of the corresponding relationship between PSCCH (Physical Sidelink Control Channel) and PSSCH (Physical Sidelink Shared Channel) resources in NR-V2X (Vehicle To Everything) provided by one embodiment of the present application;

[0017] FIG3 is a schematic diagram of a time slot structure of an NR system provided by an embodiment of the present application;

[0018] FIG4 is a schematic diagram of a second resource selection mode provided by an embodiment of the present application;

[0019] FIG5 is a schematic diagram of comb tooth size and RE (Resource Element) offset provided in one embodiment of the present application;

[0020] FIG6 is a schematic diagram of interleaved resource blocks provided by one embodiment of the present application;

[0021] FIG7 is a schematic diagram of a frame structure based on interleaved resource blocks provided by one embodiment of the present application;

[0022] FIG8 is a schematic diagram of an RB (Resource Block) set provided by one embodiment of the present application;

[0023] FIG9 is a flowchart of a resource selection method provided by one embodiment of the present application;

[0024] FIG10 is a schematic diagram of an OFDM (Orthogonal Frequency Division Multiplexing) symbol group provided by one embodiment of the present application;

[0025] FIG11 is a block diagram of a resource selection device provided by an embodiment of the present application;

[0026] FIG12 is a schematic structural diagram of a terminal device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0028] The network architecture and business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. A person skilled in the art will appreciate that, with the evolution of the network architecture and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0029] Please refer to Figure 1, which shows a schematic diagram of a network architecture provided by an embodiment of the present application. The network architecture may include: a core network 11, an access network 12, and a terminal device 13.

[0030] The core network 11 includes several core network devices. The functions of the core network devices are mainly to provide user connections, user management, and service carrying, and to provide an interface to the external network as a bearer network. For example, the core network of a 5G (5th Generation, fifth generation mobile communication technology) NR system may include devices such as an AMF (Access and Mobility Management Function) entity, a UPF (User Plane Function) entity, and an SMF (Session Management Function) entity.

[0031] The access network 12 includes several access network devices 14. The access network in the 5G NR system can be called NG-RAN (New Generation-Radio Access Network). The access network device 14 is a device deployed in the access network 12 to provide wireless communication functions for the terminal device 13. The access network device 14 may include various forms of macro base stations, micro base stations, relay stations, access points, etc. In systems using different wireless access technologies, the names of devices with access network device functions may be different. For example, in the 5G NR system, they are called gNodeB or gNB. With the evolution of communication technology, the name of "access network device" may change. For the convenience of description, in the embodiments of the present application, the above-mentioned devices that provide wireless communication functions for the terminal device 13 are collectively referred to as access network devices.

[0032] The number of terminal devices 13 is usually multiple, and one or more terminal devices 13 can be distributed in the cell managed by each access network device 14. The terminal device 13 may include various handheld devices with wireless communication functions, vehicle-mounted devices, wearable devices, computing devices or other processing devices connected to a wireless modem, as well as various forms of user equipment (UE), mobile stations (MS), etc. For the convenience of description, the devices mentioned above are collectively referred to as terminal devices. The access network device 14 and the core network device communicate with each other through some air technology, such as the NG interface in the 5G NR system. The access network device 14 and the terminal device 13 communicate with each other through some air technology, such as the Uu interface. The "terminal device" in the embodiment of the present application may also be referred to as UE or terminal, which express the same meaning.

[0033] Terminal devices 13 and terminal devices 13 (for example, vehicle-mounted devices and other devices (such as other vehicle-mounted devices, mobile phones, RSU (Road Side Unit, road side unit), etc.)) can communicate with each other through a direct communication interface (such as PC5 (ProSe Communication 5, neighbor communication fifth interface) interface). Accordingly, the communication link established based on the direct communication interface can be called a direct link or SL. SL transmission is the direct communication and data transmission between terminal devices through a side link. Unlike traditional cellular systems in which communication data is received or sent through access network equipment, SL transmission has the characteristics of short delay and low overhead, and is suitable for communication between two terminal devices with close geographical locations (such as vehicle-mounted devices and other peripheral devices with close geographical locations). It should be noted that in Figure 1, only vehicle-to-vehicle communication in the V2X scenario is used as an example. SL technology can be applied to scenarios where direct communication is carried out between various terminal devices. In other words, the terminal device in this application refers to any device that communicates using SL technology.

[0034] The "5G NR system" in the embodiments of this application may also be referred to as a 5G system or an NR system, but those skilled in the art will understand its meaning. The technical solutions described in the embodiments of this application can be applied to the 5G NR system and can also be applied to subsequent evolution systems of the 5G NR system.

[0035] Before introducing the technical solutions of this application, we first introduce and explain some of the background technologies involved in this application. The following related technologies can be combined with the technical solutions of the embodiments of this application as optional solutions, and they all fall within the scope of protection of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0036] 1. Determination of NR-V2X frequency domain resources

[0037] Similar to LTE-V2X (Long Term Evaluation), the frequency domain resources of the NR-V2X resource pool are also, and the allocation granularity of the frequency domain resources is also sub-channel. The number of PRBs (Physical Resource Blocks) included in a sub-channel is {10, 12, 15, 20, 50, 75, 100}, among which the smallest sub-channel size is 10PRB, which is much larger than the minimum sub-channel size of 4PRB in LTE-V2X. This is mainly because the frequency domain resources of PSCCH in NR-V2X are located in the first sub-channel of the PSSCH associated with it. The frequency domain resources of PSCCH are less than or equal to the size of a sub-channel of PSSCH, while the time domain resources of PSCCH occupy 2 or 3 OFDM symbols. If the sub-channel size is configured relatively small, the available resources of PSCCH will be very few, the code rate will increase, and the detection performance of PSCCH will be reduced. In NR-V2X, the size of the PSSCH subchannel and the frequency domain resource size of the PSCCH are configured independently, but the frequency domain resource of the PSCCH must be less than or equal to the subchannel size of the PSSCH. The following configuration parameters in the NR-V2X resource pool configuration information are used to determine the frequency domain resources of the PSCCH and PSSCH resource pools:

[0038] Subchannel size (sl-SubchannelSize): indicates the number of consecutive PRBs in a subchannel in the resource pool. The value range is {10, 12, 15, 20, 50, 75, 100} PRBs.

[0039] Number of subchannels (sl-NumSubchannel): indicates the number of subchannels included in the resource pool;

[0040] sl-StartRB-Subchannel: indicates the starting PRB index of the first subchannel in the resource pool.

[0041] PRB number (sl-RB-Number): indicates the number of consecutive PRBs included in the resource pool;

[0042] PSCCH frequency domain resource indicator (sl-FreqResourcePSCCH): indicates the frequency domain resource size of PSCCH, with a value range of {10, 12, 15, 20, 25} PRB;

[0043] When the UE determines the resource pool for PSSCH transmission or PSSCH reception, the frequency domain resources included in the resource pool are sl-NumSubchannel consecutive subchannels starting from the PRB indicated by sl-StartRB-Subchannel. If the number of PRBs contained in the final sl-NumSubchannel consecutive subchannels is less than the number of PRBs indicated by sl-RB-Number, the remaining PRBs cannot be used for PSSCH transmission or reception.

[0044] In NR-V2X, the frequency domain starting position of the first subchannel of PSCCH and its associated PSSCH is aligned. Therefore, the starting position of each PSSCH subchannel is the possible frequency domain starting position of PSCCH. According to the above parameters, the frequency domain range of the resource pool of PSCCH and PSSCH can be determined, as shown in Figure 2.

[0045] In NR-V2X, PSCCH is used to carry side control information related to resource sensing, including:

[0046] The priority of the scheduled transmission;

[0047] Frequency domain resource allocation, indicating the number of frequency domain resources for the PSSCH in the current time slot scheduled by the PSCCH, as well as the number and starting positions of the frequency domain resources for a maximum of two retransmission resources reserved;

[0048] Time domain resource allocation, indicating the time domain locations of up to two retransmission resources;

[0049] PSSCH reference signal pattern;

[0050] Second-order SCI (Sidelink Control Information) format;

[0051] Second-order SCI rate offset;

[0052] Number of PSSCH DMRS (Demodulation Reference Signal) ports;

[0053] MCS (Modulation and Coding Scheme);

[0054] MCS form instructions;

[0055] Number of PSFCH (Physical Sidelink Feedback Channel) symbols;

[0056] Resource reservation period: reserves resources for transmission by another TB (Transport Block) in the next period. If inter-TB resource reservation is not enabled in the resource pool configuration, this information bit field does not exist.

[0057] Reserved bits: 2 to 4 bits. The specific number of bits is configured by the network or pre-configured.

[0058] Since the PSCCH is always transmitted in the same time slot as the scheduled PSSCH, and the starting position of the PRB occupied by the PSCCH is the starting position of the first subchannel of the scheduled PSSCH, the SCI format 1-A does not explicitly indicate the time-frequency domain starting position of the scheduled PSSCH.

[0059] 2. Determination of NR-V2X time domain resources (time slots)

[0060] In NR-V2X, the transmission of PSCCH / PSSCH is based on the time slot level, that is, only one PSCCH / PSSCH can be transmitted in one time slot. It does not support the transmission of multiple PSCCH / PSSCH in one time slot through TDM (Time Division Multiplexing). The PSCCH / PSSCH between different users can be multiplexed in one time slot through FDM (Frequency Division Multiplexing). The time domain resources of PSSCH in NR-V2X are based on the time slot granularity, but unlike the PSSCH in LTE-V2X that occupies all the time domain symbols in a subframe, the PSSCH in NR-V2X can occupy part of the symbols in a time slot. This is mainly because in the LTE system, uplink or downlink transmissions are also based on the subframe granularity, so the side transmission is also based on the subframe granularity (special subframes in the TDD system are not used for side transmission). The NR system uses a flexible time slot structure, meaning that a time slot includes both uplink and downlink symbols, enabling more flexible scheduling and reducing latency. A typical NR system subframe is shown in Figure 3. A time slot can include downlink (DL) symbols, uplink (UL) symbols, and flexible symbols. Downlink symbols are located at the beginning of the time slot, while uplink symbols are located at the end of the time slot. Flexible symbols are located between downlink and uplink symbols, and the number of each type of symbol in each time slot is configurable.

[0061] The sidelink transmission system can share a carrier with the cellular system. In this case, the sidelink transmission can only use the uplink transmission resources of the cellular system. For NR-V2X, if the sidelink transmission still needs to occupy all the time domain symbols in a time slot, the network needs to configure a time slot full of uplink symbols for sidelink transmission. This will have a significant impact on the uplink and downlink data transmission of the NR system and reduce the system performance. Therefore, in NR-V2X, part of the time domain symbols in the time slot are supported for sidelink transmission, that is, part of the uplink symbols in a time slot are used for sidelink transmission. In addition, considering that the sidelink transmission includes AGC (Automatic Gain Control) symbols and GP (Guard Period) symbols, if the number of uplink symbols available for sidelink transmission is small, after removing the AGC symbols and GP symbols, the remaining symbols available for transmitting valid data are even fewer, and the resource utilization rate is very low. Therefore, the time domain symbols occupied by the sidelink transmission in NR-V2X are at least 7 (including GP symbols). When the sideline transmission system uses a dedicated carrier, there is no problem of sharing transmission resources with other systems, and all symbols in the time slot can be configured to be used for sideline transmission.

[0062] As mentioned above, NR-V2X configures the starting point and length of the time domain symbol used for sideline transmission in a time slot through the parameters starting symbol position (sl-StartSymbol) and number of symbols (sl-LengthSymbols). The last symbol in the time domain symbol used for sideline transmission is used as the guard interval GP. PSSCH and PSCCH can only use the remaining time domain symbols. However, if PSFCH transmission resources are configured in a time slot, PSSCH and PSCCH cannot occupy the time domain symbol used for PSFCH transmission, as well as the AGC and GP symbols before the symbol.

[0063] In the NR-V2X system, the time domain resources of the resource pool are also indicated by a bitmap. Considering the flexible time slot structure in the NR system, the length of the bitmap has been extended to support a bitmap length range of [10:160]. The method of using the bitmap to determine the time slot position belonging to the resource pool within an SFN cycle is the same as that in LTE-V2X, but with the following two differences:

[0064] The total number of time slots included in one SFN cycle is 10240×2 μ , where the parameter μ is related to the subcarrier spacing;

[0065] If at least one of the time-domain symbols Y, Y+1, Y+2, …, Y+X-1 included in a time slot is not configured as an uplink symbol by the network's TDD-UL-DL-ConfigCommon signaling, then the time slot cannot be used for sidelink transmission. Where Y and X represent sl-StartSymbol and sl-LengthSymbols, respectively.

[0066] The specific steps include:

[0067] Step 1: Remove the time slots that do not belong to the resource pool within the SFN (System Frame Number) period, including synchronization time slots and time slots that cannot be used for sideline transmission. The remaining time slots are represented as the remaining time slot set, and the remaining time slots are renumbered as

[0068] in:

[0069] N S_SSB Indicates the number of synchronization time slots in an SFN cycle; the synchronization time slot is determined according to synchronization-related configuration parameters, and is related to the period of transmitting SSB (Synchronization Signal Block) and the number of SSB transmission resources configured in the period.

[0070] N nonSL Indicates the number of time slots in an SFN cycle that do not comply with the uplink symbol start point and number configuration: If at least one of the time domain symbols Y, Y+1, Y+2, …, Y+X-1 included in a time slot is not semi-statically configured as an uplink symbol, then the time slot cannot be used for sidelink transmission, where Y and X represent sl-StartSymbol and sl-LengthSymbols, respectively.

[0071] Step 2: Determine the number of reserved time slots and their corresponding time domain locations.

[0072] If the number of time slots in the remaining time slot set cannot be divided by the bitmap length, the number of reserved time slots and the corresponding time domain positions need to be determined. r (0≤r<10240×2 μ -N S_SSB -N nonSL ) satisfies the following conditions, then the time slot is a reserved time slot,

[0073] Where: N reserved =(10240×2 μ -N S_SSB -N nonSL )mod Lbitmap , represents the number of reserved time slots, L bitmap Indicates the length of the bitmap, m = 0, ..., N reserved -1.

[0074] Step 3: Remove the reserved time slots from the remaining time slot set. The remaining time slot set is represented as a logical time slot set. The time slots in the time slot set are all time slots that can be used in the resource pool. The time slots in the logical time slot set are renumbered as Among them, T max =10240×2 μ -N S_SSB -N nonSL -N reserved .

[0075] Step 4: Determine the time slots in the logical time slot set that belong to the resource pool according to the bitmap. The bitmap in the resource pool configuration information is For a time slot in a logical time slot set When b is satisfied k′ =1, the time slot belongs to the resource pool, where k′=k mod L bitmap .

[0076] Step 5: Renumber the time slots in the resource pool identified in step 4 into Among them, T′ max Indicates the number of time slots included in the resource pool.

[0077] 3. Second resource selection mode in NR SL

[0078] In resource allocation mode 2, the UE upper layer can request the UE physical layer to determine a resource subset from which the UE upper layer will select resources for PSSCH / PSCCH transmission. To trigger this process, in time slot n, the UE upper layer provides the following parameters related to PSSCH / PSCCH transmission to the physical layer:

[0079] a resource pool of the resource subset;

[0080] Physical layer priority, prio TX ;

[0081] Remaining delay budget (PDB);

[0082] The number of subchannels used for PSSCH / PSCCH transmission in a time slot, L subCH ;

[0083] Optional, resource reservation period P rsvp_TX Unit: ms.

[0084] The following high-level configuration parameters affect the resource subset determination process:

[0085] sl-SelectionWindowList: Configuration for different prio TX T 2min The minimum value, T 2min Set to sl-SelectionWindowList for prio TX The configured value;

[0086] sl-ThresPSSCH-RSRP-List: configure each (p i ,p j ) combination corresponding to the RSRP threshold, where p i is the priority indicated in the received SCI, p j =prio TX .

[0087] sl-RS-ForSensing: instructs the UE to use PSSCH-RSRP or PSCCH-RSRP measurement results for resource exclusion;

[0088] sl-ResourceReservePeriodList: indicates the resource reservation period available in the resource pool;

[0089] sl-SensingWindow: indicates the starting point T0 of the resource listening window, where T0 is defined as the number of time slots corresponding to sl-SensingWindow milliseconds.

[0090] ·sl-TxPercentageList: The remaining resource ratio X after the configuration resources are exhausted. TX , X is defined as sl-TxPercentageList(prio TX );

[0091] sl-PreemptionEnable: Indicates whether resource preemption is enabled in the resource pool, and if so, the resource preemption priority. pre The value of

[0092] If the UE higher layer provides a resource reservation period P rsvp_TX (unit: ms), then P rsvp_TX Converted to the number of logical time slots P′ rsvp_TX .

[0093] As shown in FIG4 , the steps for the UE physical layer to determine the resource subset are as follows:

[0094] 1) Define candidate single-slot resources R for transmission x,y Time slot Continuous L within subCH subchannels, the subchannel index is x+j, j=0,...,L subCH -1. UE assumes that any L in the time range [n+T1, n+T2] subCH A continuous sub-channel corresponds to a single time slot resource.

[0095] -0≤T1≤T proc,1 The specific value is determined by the UE implementation. When the subcarrier spacing is 15, 30, 60, or 120 kHz, T proc,1 There are 3, 5, 9 and 17 time slots respectively.

[0096] -If T 2min If it is less than the remaining delay budget (PDB) of the data packet in time slots, then T 2min ≤T2≤PDB, the specific value is determined by the UE implementation. Otherwise, T2 is equal to PDB, where PDB is indicated by the UE upper layer. 2min The value set is {1,5,10,20}×2 μ time slots, where μ = 0, 1, 2, 3 corresponds to the case where the subcarrier spacing is 15, 30, 60, 120 kHz. The UE sends data based on its priority level prio TX Determine T from this value set 2min .

[0097] The total number of candidate single-slot resources is M total .

[0098] 2) The resource listening window is defined as The time slots in the range of T0 are defined as above. When the subcarrier spacing is 15, 30, 60, 120 kHz, T proc,0 The number of time slots is 1, 1, 2, and 4 respectively. The UE shall monitor the time slots belonging to the sidelink resource pool within the resource listening window unless the UE performs a transmission operation on a time slot.

[0099] 3) Set the parameter Th(p i ,p j ) is set to the i-th value of the sl-ThresPSSCH-RSRP-List configuration, where i = p i +(p j -1)*8.

[0100] 4) Set S AInitialized to all candidate single-slot resources.

[0101] 5) If the following conditions are met, the UE shall exclude S A Candidate resources R x,y :

[0102] -UE does not listen to the time slot in 2)

[0103] -For the number of logical time slots P corresponding to any resource reservation period allowed in the resource pool configured by sl-ResourceReservePeriodList, y=m+P.

[0104] 6) If the following conditions are met, the UE shall exclude S A Candidate resources R x,y :

[0105] a)UE in time slot Receive SCI format 1-A, in which the 'Resource reservation period' field (if present) and the 'Priority' field indicate P rsvp_RX and prio RX ;

[0106] b) The RSRP measured for the received SCI is higher than Th(prio RX ,prio TX );

[0107] c) In time slot Received SCI format 1-A indicates and reserved PSSCH resources and If the received SCI format 1-A contains the 'Resource reservation period' field, it is assumed that the time slot The received SCI indicates the same format and reserved resources and Overlap. Where q=1,2,…,Q,j=0,1,…,C resel -1. Here, P′ rsvp_RX It is from P rsvp_RX The number of logical time slots converted; if P rsvp_RX <T scal And n′-m≤P′ rsvp_RX , where if time slot n belongs to the set otherwise The first one after time slot n time slot; otherwise Q=1. T scalis the value in milliseconds converted from T2. resel is the number of PSSCH transmission opportunities to be selected. Indicates the set of logical time slots contained in the current resource pool.

[0108] 7) If the set S A The number of single-slot resources remaining in the time slot is less than X·M total , then UE will Th(p i ,p j ) by 3dB and proceed to step 4).

[0109] The UE physical layer will S A Report to the MAC (Media Access Control) layer.

[0110] 4. Downlink-based positioning

[0111] In downlink positioning, up to four positioning frequency layers (Frequency Layer) of DL PRS (Downlink Positioning Reference Signal) configurations can be provided for a UE. The parameter structure of each positioning frequency layer provides the following PRS signal configuration parameters:

[0112] The subcarrier spacing of the PRS signal.

[0113] The cyclic prefix (CP) length of the PRS signal.

[0114] PRS frequency domain resource bandwidth: This parameter is the number of PRBs allocated to the PRS signal. The minimum PRS resource bandwidth is 24 PRBs, with a granularity of 4 PRBs, and the maximum is 272 PRBs.

[0115] PRS resource frequency domain starting frequency position: This parameter defines the index of the starting PRB of the PRS signal in the frequency domain. The PRB index is defined relative to Point A of the PRS.

[0116] The frequency domain reference point of the PRS signal is PointA.

[0117] The comb size of the PRS signal, Comb-N.

[0118] The above PRS parameters configured in each positioning frequency layer will be applied to all PRS resources contained in this positioning frequency layer. That is to say, in a positioning frequency layer, all PRS signals from multiple different TRPs (Transmit Receive Points) will use the same subcarrier spacing and CP length, the same comb size, be sent on the same frequency subband, and occupy exactly the same bandwidth. This design can support the UE to simultaneously receive and measure PRS signals from multiple different TRPs on the same frequency point.

[0119] The parameters of the TRP layer include an ID (Identity Document) parameter used to uniquely identify the positioning TRP, the physical cell ID of the TRP, the NR Cell Global Identifier (NCGI) of the TRP, and the ARFCN (Absolute Radio Frequency Channel Number) of the TRP. Up to two DL PRS resource sets can be configured in each TRP layer. The parameters of the DL PRS resource set layer are configured with the following parameters, which will apply to all DL PRS resources contained in this resource set.

[0120] DL PRS resource set identification ID (nr-DL-PRS-ResourceSetID).

[0121] DL PRS transmission period and time slot offset (dl-PRS-Periodicity-and-ResourceSetSlotOffset): This parameter defines the time domain transmission behavior of all DL PRS resources included in this DL PRS resource set. The minimum value of the configurable DL PRS transmission period is 4 milliseconds, and the maximum value is 10240 milliseconds. The configuration of DL PRS supports flexible subcarrier spacing, including 15KHz, 30KHz, 60KHz and 120KHz. Under different subcarrier spacing conditions, the range of configurable DL PRS transmission period values ​​is the same. Figure 5 shows a schematic diagram of a comb size of 2 and RE offsets of 0 and 1.

[0122] · DL PRS resource repetition factor (dl-PRS-ResourceRepetitionFactor): This parameter defines the number of times a PRS resource is repeatedly transmitted in each PRS period. The repeated transmission of the same DL PRS resource can be used by the UE to aggregate the DL PRS signal energy of multiple transmissions, thereby increasing the coverage distance of the DL PRS and increasing the positioning accuracy. In the FR2 system, the repeated transmission of the DL PRS resource can be used by the UE to perform receive beam scanning operations. The UE can use different receive beams to receive the repeated transmission of the same DL PRS resource to find the best TRP transmit beam and UE receive beam match. On the other hand, the repeated transmission of DL PRS resources will increase the overhead of PRS. In the 3GPP NR R16 specification, the repetition factor of the DL PRS resource is 1, 2, 4, 6, 8, 16 and 32.

[0123] DL-PRS-ResourceTimeGap: This parameter defines the number of time slots between two consecutive retransmissions of the same PRS resource.

[0124] · Muting configuration of DL PRS: This parameter is used to define that the DL PRS signal is not sent on certain allocated time-frequency resources (called muting). Muting means that the DL PRS signal is not sent on all allocated time-frequency resources, but is intentionally not sent on certain designated time-frequency resources. The purpose of doing this is to avoid conflicts with other signals such as SSB on the one hand, and to avoid interference between signals sent by different TRPs on the other hand. For example, the DL PRS transmission of a certain TRP is intentionally turned off at certain moments so that the UE can receive the DL PRS signal from a farther TRP. The muting operation of PRS will be explained in detail in the subsequent description, so I will not go into details here.

[0125] Number of OFDM symbols occupied by DL PRS resources (dl-PRS-NumSymbols): This parameter defines the number of OFDM symbols allocated to a DL PRS resource within a time slot.

[0126] As mentioned above, all parameters configured in a DL PRS resource set are applied to all DL PRS resources contained in the resource set. Therefore, all DL PRS resources in the same DL PRS resource set are transmitted with the same periodicity, the same number of repetitions, and occupy the same number of OFDM symbols.

[0127] Each DL PRS resource is configured with the following parameters:

[0128] A DL PRS resource identification ID (nr-DL-PRS-ResourceID).

[0129] DL PRS sequence ID (dl-PRS-SequenceID).

[0130] DL PRS Starting Frequency Resource Unit Offset (dl-PRS-CombSizeN-AndReOffset): This parameter defines the frequency resource unit offset used for resource mapping of the DL PRS resource to the first allocated OFDM symbol within a slot. Based on this parameter and the relative offset values ​​specified in TS 38.211, the UE can determine the frequency resource unit offset used for resource mapping on each OFDM symbol.

[0131] DL PRS resource slot offset (dl-PRS-ResourceSlotOffset): This parameter defines the time slot offset relative to the DL PRS resource set. This parameter can determine the time slot position of each DL PRS resource.

[0132] DL PRS OFDM symbol offset (dl-PRS-ResourceSymbolOffset): This parameter defines the time-frequency resource allocation position of a DL PRS resource within a time slot. It indicates the starting OFDM symbol index within a time slot.

[0133] DL PRS QCL information (dl-PRS-QCL-Info): This parameter provides the Quasi Co-Location (QCL) information of the DL PRS signal.

[0134] 5. Sidelink transmission in unlicensed spectrum (SL-U)

[0135] When performing sidelink transmission over unlicensed spectrum (SL-U), sidelink transmission must meet specific regulatory requirements, including minimum occupied channel bandwidth (OCB) and maximum power spectral density (PSD). For OCB requirements, the UE must occupy at least 80% of the channel bandwidth when using the channel for data transmission. For maximum power spectral density requirements, the UE's transmit power per 1MHz must not exceed 10dBm. To meet OCB and PSD regulatory requirements, sidelink transmission over unlicensed spectrum uses an interlaced resource block (IRB) structure. An IRB consists of N discrete resource blocks (RBs) in the frequency domain. A total of M IRBs exist within the frequency band, and the mth IRB consists of RBs in the order {m, M+m, 2M+m, 3M+m, ...}.

[0136] As shown in FIG6 , the system bandwidth includes 20 RBs, including 5 IRBs (i.e., M=5), each IRB includes 4 RBs (i.e., N=4), and the frequency domain intervals of two adjacent RBs belonging to the same IRB are the same, i.e., 5 RBs apart. The numbers in the boxes in the figure represent the IRB indexes.

[0137] In the SL-U system, if IRB-based resource allocation granularity is adopted, channels such as the PSCCH and PSSCH in the SL-U system should all be based on the IRB structure. In this case, the frame structure of the SL-U system is shown in Figure 7, where the numbers within the boxes represent the IRB indexes. Figure 7 illustrates a frame structure where only the PSCCH and PSSCH are included in a time slot, excluding the PSFCH. The bandwidth shown in the figure includes 20 RBs, with five IRB resources configured (i.e., M = 5). Each IRB resource consists of four RBs, and the numbers within the boxes represent the IRB indexes. In Figure 7, the system configures the PSCCH to occupy one IRB resource and two OFDM symbols in the time domain. The PSSCH uses IRB granularity, with the first symbol in the time slot being an AGC symbol and the last symbol being a GP symbol. In the figure, PSSCH1 occupies IRB#0 and IRB#1, with its corresponding PSCCH1 occupying IRB#0. PSSCH2 occupies IRB#2, with its corresponding PSCCH2 also occupying IRB#2. It should be noted that, for the sake of simplicity, the figure does not show the resources occupied by the second-order SCI and the resources occupied by the PSCCH DMRS and PSSCH DMRS.

[0138] In unlicensed spectrum, UEs access channels through LBT (Listen Before Talk). LBT uses a granularity of 20 MHz in the frequency domain, with each 20 MHz being called an RB Set. A carrier can include multiple RB Sets, with guard intervals between RB Sets, as shown in Figure 8.

[0139] In the unlicensed spectrum, the UE needs to perform LBT first. Only after passing LBT can it access the channel. However, the time for the UE to complete LBT is uncertain. If the UE is restricted to sending from the starting point of a time slot, the UE may miss the sending opportunity because it fails to complete LBT before then. Therefore, in SL-U, it is considered to add a sending starting point within a time slot, that is, multi-starting point transmission. For example, the additional starting point can be the 3rd or 4th OFDM symbol in the time slot.

[0140] 6. Positioning based on sidelink

[0141] 3GPP RAN conducted research on "NR Positioning Enhancements" and "Scenarios and Requirements for NR Positioning Use Cases in In-Coverage, Partial Coverage, and Out-of-Coverage." The latter study focused on V2X and public safety use cases. Furthermore, the 3GPP SA1 Working Group developed requirements for "Ranging-Based Services" and positioning accuracy requirements for IIoT use cases in out-of-coverage scenarios. 3GPP is required to research and develop sidelink positioning solutions to support the use cases, scenarios, and requirements identified in these activities.

[0142] To improve positioning accuracy, especially for UEs outside cellular network coverage, 3GPP has completed feasibility and performance studies on positioning technologies based on sidetrack positioning reference signals. Next, 3GPP will standardize solutions for sidetrack positioning (including ranging and direction finding) in NR systems.

[0143] On the sidelink, different UEs may send SL PRS using different time-frequency resources, and how the PSCCH used to indicate SL PRS transmission should be multiplexed is an unresolved issue. To address this issue, the following embodiments of this application provide a solution, which will be elaborated in detail below. In addition, in this application, unless otherwise stated, all indexes / numbers are counted starting from 0.

[0144] In the second resource selection mode in NR SL, after the UE physical layer performs resource exclusion and reports the resource set subset to the UE MAC layer, there is no solution to the problem of how the UE MAC layer should select SL PRS resources to minimize resource collision or mutual interference with other UEs.

[0145] Please refer to Figure 9, which shows a flow chart of a resource selection method provided by an embodiment of the present application. The method is executed by a terminal device and may include the following step 910.

[0146] Step 910: The terminal device selects at least one SL PRS resource from the SL PRS resource set, where the SL PRS resource is used to send the SL PRS.

[0147] The SL PRS resource set includes at least one resource for sending the SL PRS.

[0148] In some embodiments, the terminal device randomly selects at least one SL PRS resource from the SL PRS resource set. In some embodiments, the upper layer of the terminal device randomly selects at least one SL PRS resource from the SL PRS resource set. The upper layer refers to a layer located above the physical layer, such as the MAC layer.

[0149] In some embodiments, the terminal device selects one SL PRS resource from the SL PRS resource set, and the SL PRS resource is used for the initial transmission of the SL PRS.

[0150] In some embodiments, the terminal device selects multiple SL PRS resources from the SL PRS resource set, and the multiple SL PRS resources include one SL PRS resource for initial transmission and at least one SL PRS resource for retransmission.

[0151] In some embodiments, the SL PRS resource used for initial transmission is the first resource among the at least one SL PRS resource, where the first resource refers to the resource that is at the front in the time domain among the at least one SL PRS resource.

[0152] In some embodiments, a plurality of SL PRS resources are selected, and the plurality of SL PRS resources occupy OFDM symbol groups at the same position in different time domain units, or the plurality of SL PRS resources occupy OFDM symbol groups at adjacent positions in different time domain units; wherein, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol. The time domain unit can be a time slot, a subframe, or other time domain unit, which is not limited in this application. One time domain unit includes 14 OFDM symbols.

[0153] In some embodiments, the OFDM symbol groups included in different time domain units are the same, or in other words, the OFDM symbol groups in different time domain units are grouped in the same way. For example, as shown in Figure 10, a time domain unit includes three OFDM symbol groups, wherein the first symbol group includes OFDM symbols with indices 3 to 6, the second symbol group includes OFDM symbols with indices 7 to 10, and the third symbol group includes OFDM symbols with indices 11 to 12, and each time domain unit includes three OFDM symbol groups as shown in Figure 10. Figure 10 only gives an example of an OFDM symbol group included in a time domain unit, and this application does not limit the OFDM symbol groups included in a time domain unit. For example, a time domain unit may include one or more OFDM symbol groups.

[0154] The symbol groups in the same position refer to the OFDM symbols included in the symbol group occupying the same position in the time domain unit. The number of OFDM symbol groups occupied in each time domain unit may be one or more, and this application does not limit this. Taking the symbol groups included in the time domain unit shown in Figure 10 as an example, the selected SL PRS resources occupy the first symbol group in time domain unit 1, and the selected SL PRS resources also occupy the first symbol group in time domain unit 2. For another example, the selected SL PRS resources occupy the first symbol group and the second symbol group in time domain unit 1, and the selected SL PRS resources also occupy the first symbol group and the second symbol group in time domain unit 2. Time domain unit 1 and time domain unit 2 are different time domain units, and the two may be adjacent time domain units or non-adjacent time domain units.

[0155] In some embodiments, multiple SL PRS resources are selected, and the multiple SL PRS resources occupy the same OFDM symbol group in different time domain units and use the same RE offset, which can minimize the number of signaling bits used to indicate the SL PRS resources.

[0156] If no other OFDM symbols and / or OFDM symbol groups exist between two OFDM symbol groups, then the two OFDM symbol groups are called adjacent symbol groups. If no other OFDM symbols exist between the i-th OFDM symbol group and the i+1-th OFDM symbol group, then the multiple OFDM symbol groups are called adjacent symbol groups, where i is an integer greater than 0. For example, in Figure 10 , the first and second symbol groups are called adjacent symbol groups, the second and third symbol groups are called adjacent symbol groups, and the first, second, and third symbol groups are called adjacent symbol groups. However, the first and third symbol groups are not adjacent symbol groups.

[0157] Multiple SL PRS resources occupying OFDM symbol groups at adjacent positions in different time domain units means that, among multiple SL PRS resources, SL PRS resources located in the same time domain unit occupy OFDM symbol groups at adjacent positions in the time domain unit. The OFDM symbol groups at adjacent positions occupied by multiple SL PRS resources in different time domain units may be the same or different, and this application does not limit this. Taking the symbol groups included in the time domain unit shown in Figure 10 as an example, for example, among multiple SL PRS resources, the OFDM symbol groups occupied by the SL PRS located in time domain unit 1 are the first symbol group and the second symbol group, and the OFDM symbol groups occupied by the SL PRS resources located in time domain unit 2 are the second symbol group and the third symbol group. For another example, among multiple SL PRS resources, the OFDM symbol groups occupied by the SL PRS located in time domain unit 1 are the first symbol group and the second symbol group, and the OFDM symbol groups occupied by the SL PRS resources located in time domain unit 2 are the first symbol group and the second symbol group.

[0158] In some embodiments, the time domain interval between the selected two adjacent SL PRS resources is greater than 0 and less than or equal to a fourth threshold. The time domain interval refers to the time domain unit interval, that is, the number of time domain units between the time domain units occupied by the selected two adjacent SL PRS resources. Two adjacent SL PRS resources refer to the absence of a third SL PRS resource between the two SL PRS resources. For example, the first SL PRS resource and the second SL PRS resource are two adjacent SL PRS resources, the first SL PRS resource occupies time domain unit 1, the second SL PRS resource occupies time domain unit 2, and the number of time domain units between time domain unit 1 and time domain unit 2 is called the time domain interval.

[0159] In some embodiments, the fourth threshold may be network-configured, preconfigured, or predefined, which is not limited in this application. For example, the fourth threshold is 32, which means that the time domain interval between two adjacent SL PRS resources is greater than 0 and less than 32.

[0160] In some embodiments, the above-mentioned multiple SL PRS resources are indicated by an SCI, and the SCI is used to indicate the configuration information of the SL PRS.

[0161] The technical solution provided in the embodiment of the present application is that the terminal device selects at least one SL PRS resource in the SL PRS resource set. The number of candidate resources in the SL PRS resource set is large, which can effectively reduce resource collision or mutual interference with other terminal devices.

[0162] For SL PRS resource sets, this application provides several resource selection methods under different SL PRS resource sets.

[0163] 1. The SL PRS resource set includes all SL PRS resources configured or pre-configured in the resource pool, or the SL PRS resource set includes SL PRS resources configured or pre-configured in the resource pool within the first time domain.

[0164] The first time domain range refers to the time domain range of the last time domain unit before the remaining delay from the current time domain unit to the SL PRS. The remaining delay of the SL PRS refers to the remaining time domain units in which the SL PRS needs to be sent, or the remaining time domain range with positioning requirements. The remaining delay of the SL PRS is determined based on the service to which the SL PRS is applied. For example, if the service ends after 10 time domain units, then the remaining delay of the SL PRS is also the 10 time domain units, and the first time domain range is the time domain range from the current time domain unit to the 9th time domain unit.

[0165] A resource pool refers to a collection of resources, which may be a resource pool used for sidelink transmission or any resource pool including SL PRS resources.

[0166] An SL PRS resource refers to a time-frequency resource used for SL PRS transmission in a time domain unit. An SL PRS resource includes at least the following characteristics:

[0167] SL PRS resource ID;

[0168] The comb size and RE offset of the SL PRS sent within the SL PRS resource;

[0169] The starting OFDM symbol of the SL PRS resource in the time slot and the number of consecutive OFDM symbols occupied;

[0170] ·The RBs occupied by the SL PRS resources in the above OFDM symbols.

[0171] The SL PRS resource ID is used to uniquely identify the SL PRS resource. The SL PRS comb tooth size refers to the number of intervals between REs occupied by the SL PRS, and the RE offset refers to the position of the first RE occupied by the SL PRS resource in an OFDM symbol.

[0172] The SL PRS resources in the resource pool can be network configured or pre-configured. Exemplarily, the network device sends configuration / pre-configuration information to the terminal device. The configuration / pre-configuration information can clearly indicate all of the above characteristics of each SL PRS resource, or only clearly indicate some of the characteristics. As an example of indicating only some of the characteristics, the configuration / pre-configuration information only clearly indicates the SL PRS resource ID, the comb size and RE offset of the SL PRS sent in the SL PRS resource, and the starting OFDM symbol of the SL PRS resource in the time slot and the number of continuous OFDM symbols occupied, but does not clearly indicate the RB occupied by the SL PRS resource. In this case, the RB occupied by each configured / pre-configured SL PRS resource is the same as the RB configured in the resource pool. The RB configured in the resource pool can be understood as the RB occupied by the resource pool.

[0173] In this case, the terminal device randomly selects at least one SL PRS resource from the SL PRS resource set. For example, the number of SL PRS transmissions to be sent is N+1, including one initial transmission and N retransmissions. If there are remaining resources in the SL PRS resource set, the terminal device selects N+1 SL PRS resources from the resource set, uses the first SL PRS resource among the N+1 SL PRS resources as the initial transmission resource of the SL PRS, and uses the remaining SL PRS resources as the retransmission resources of the SL PRS, where N is a natural number.

[0174] In some embodiments, the N+1 SL PRS resources may be indicated by an SCI, where the SCI is used to indicate configuration information of the SL PRS.

[0175] In some embodiments, a time domain interval between two adjacent SL PRS resources among the N+1 SL PRS resources is greater than 0 and less than or equal to a fourth threshold.

[0176] In some embodiments, multiple SL PRS resources are selected, and the multiple SL PRS resources occupy the same position OFDM symbol group in different time domain units, or the multiple SL PRS resources occupy adjacent position OFDM symbol groups in different time domain units, which can reduce the indication signaling overhead.

[0177] In some embodiments, if the number of SL PRS resources in the SL PRS resource set is less than N+1, all the SL PRS resources in the SL PRS resource set are selected as the resources of the SL PRS.

[0178] By using the above method, the number of candidate SL PRS resources in the SL PRS resource set is maximized, which can reduce the possibility of resource collision between different terminal devices as much as possible.

[0179] 2. The SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool, or the SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool within the first time domain.

[0180] In other words, the SL PRS resource set is a subset of the SL PRS resources configured or pre-configured in the resource pool, or the SL PRS resource set is a subset of the SL PRS resources configured or pre-configured in the resource pool within the first time domain.

[0181] In this case, the terminal device randomly selects at least one SL PRS resource from the SL PRS resource set. For example, the number of SL PRS transmissions to be sent is N+1, including one initial transmission and N retransmissions. If there are remaining resources in the SL PRS resource set, the terminal device selects N+1 SL PRS resources from the resource set, uses the first SL PRS resource among the N+1 SL PRS resources as the initial transmission resource of the SL PRS, and uses the remaining SL PRS resources as the retransmission resources of the SL PRS, where N is a natural number.

[0182] In some embodiments, the N+1 SL PRS resources may be indicated by an SCI, where the SCI is used to indicate configuration information of the SL PRS.

[0183] In some embodiments, a time domain interval between two adjacent SL PRS resources among the N+1 SL PRS resources is greater than 0 and less than or equal to a fourth threshold.

[0184] In some embodiments, the number of OFDM symbols occupied by the SL PRS resources included in the SL PRS resource set is greater than or equal to a first threshold, and the comb tooth size is less than or equal to a second threshold.

[0185] In some embodiments, the first threshold and the second threshold are determined by the transmitting device of the SL PRS and / or the receiving device of the SL PRS. For example, the first threshold and the second threshold are determined based on the positioning requirements of the transmitting device of the SL PRS and / or the positioning requirements of the receiving device of the SL PRS. The positioning requirements may include positioning accuracy requirements, positioning range requirements, etc.

[0186] In some embodiments, the effective comb tooth size of the SL PRS resources included in the SL PRS resource set is greater than or equal to a third threshold, and the effective comb tooth size is the product of the comb tooth size of the SL PRS resources and the number of OFDM symbols occupied by the SL PRS.

[0187] In some embodiments, the third threshold may be determined using the same method as the first threshold and / or the second threshold.

[0188] Through the above-mentioned first threshold and second threshold, or third threshold, the SL PRS resources configured or pre-configured in the resource pool that cannot meet the positioning requirements can be excluded from the candidate resource set, thereby improving the positioning accuracy.

[0189] In some embodiments, the SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at the same position in different time domain units, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol. Taking the OFDM symbol group included in the time domain unit shown in Figure 10 as an example, the SL PRS included in the SL PRS resource set occupies the first symbol group in different time domain units. For example, the SL PRS resources included in the SL PRS resource set occupy the first symbol group of time domain unit 1 and the first symbol group of time domain unit 2.

[0190] In some embodiments, the SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at adjacent positions in different time domain units, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol. Taking the OFDM symbol group included in the time domain unit shown in Figure 10 as an example, the SL PRS included in the SL PRS resource set occupies the first symbol group and the second symbol group, or occupies the second symbol group and the third symbol group, or occupies the first symbol group, the second symbol group and the third symbol group in different time domain units. For example, the SL PRS resources included in the SL PRS resource set occupy the first symbol group and the second symbol group of time domain unit 1, the first symbol group, the second symbol group and the third symbol group of time domain unit 2, and the second symbol group and the third symbol group of time domain unit 3.

[0191] Through the above method, the terminal device can exclude the SL PRS resources that cannot meet the positioning requirements from the SL PRS resource set configured or pre-configured in the resource pool, thereby ensuring the accuracy of positioning. In addition, the SL PRS resources included in the SL PRS resource set occupy the OFDM symbol group at the same position in different time domain units, or occupy the OFDM symbol group at adjacent positions, which can also reduce the overhead of resource indication signaling.

[0192] 3. SL PRS resource set is determined based on resource listening

[0193] 3.1. Select at least one SL PRS resource from the SL PRS resource set

[0194] The above-mentioned SL PRS resource set refers to the SL PRS resource set determined based on resource listening, which includes all configured or pre-configured SL PRS resources in the resource pool except for the excluded SL PRS resources, or the resource set includes all configured or pre-configured SL PRS resources in the resource pool within the first time domain range except for the excluded SL PRS resources.

[0195] The excluded SL PRS resources include occupied SL PRS resources and reserved SL PRS resources.

[0196] In some embodiments, after resource sensing, the physical layer of the terminal device sends a SL PRS resource set to a higher layer, where the SL PRS resource set is determined based on the resource sensing.

[0197] 3.2. Prioritize selecting at least one SL PRS resource from the first resource subset of the SL PRS resource set. There is no excluded SL PRS resource on the OFDM symbol where the SL PRS resources included in the first resource subset are located.

[0198] In some embodiments, since the SL PRS is mapped to the RE of the OFDM symbol using a comb-tooth structure, and since the RE offsets of different SL PRS resources are different, one OFDM symbol may include one or more OFDM symbols. For example, one OFDM symbol may include three SL PRS resources with a comb-tooth size of 3 and RE offsets of 0, 1, and 2 respectively.

[0199] In some embodiments, there are no excluded SL PRS resources on the OFDM symbol where the SL PRS resources included in the first resource subset are located, that is, the SL PRS resources on the OFDM symbol are not occupied or reserved.

[0200] In this case, the terminal device randomly selects at least one SL PRS resource from the SL PRS resource set. For example, the number of SL PRS transmissions to be sent is N+1, including one initial transmission and N retransmissions. If there are remaining resources in the SL PRS resource set, the terminal device selects N+1 SL PRS resources from the resource set, uses the first SL PRS resource among the N+1 SL PRS resources as the initial transmission resource of the SL PRS, and uses the remaining SL PRS resources as the retransmission resources of the SL PRS, where N is a natural number.

[0201] In some embodiments, the N+1 SL PRS resources may be indicated by an SCI, where the SCI is used to indicate configuration information of the SL PRS.

[0202] In some embodiments, a time domain interval between two adjacent SL PRS resources among the N+1 SL PRS resources is greater than 0 and less than or equal to a fourth threshold.

[0203] In some embodiments, multiple SL PRS resources are selected, and the multiple SL PRS resources occupy OFDM symbol groups at the same position in different time domain units, or the multiple SL PRS resources occupy OFDM symbol groups at adjacent positions in different time domain units.

[0204] In some embodiments, if the number of SL PRS resources selected from the first resource subset is less than a first value, at least one additional SL PRS resource is selected from the second resource subset, and the second resource subset includes the SL PRS resources in the SL PRS resource set except the first resource subset.

[0205] The first value refers to the number of SL PRS resources required to send the SL PRS. For example, if the SL PRS requires one initial transmission and N retransmissions, the first value is N+1. Exemplarily, if the number of SL PRS resources included in the first resource subset is less than N+1, the SL PRS resources included in the first resource subset are used as the resources required to send the SL PRS, and the remaining required SL PRS resources are selected from the second resource subset.

[0206] Through the above method, there are no other SL PRS resources in the OFDM symbols occupied by the selected SL PRS resources, which reduces the possibility of frequency division multiplexing of SL PRS resources with other terminal devices, thereby reducing the impact of in-band leakage.

[0207] 3.3. Select at least one SL PRS resource from a third resource subset of the SL PRS resource set, where the third resource subset is determined based on the number of SL PRS resources excluded on the OFDM symbol.

[0208] As described in method 3.2, if there are no SL PRS resources that meet the conditions of the first resource subset among the SL PRS resources configured or pre-configured in the resource pool, or the number of SL PRS resources in the first resource subset is insufficient to meet the needs of SL PRS, the problem of in-band leakage still exists, and method 3.2 provides a solution to this problem.

[0209] In some embodiments, the SL PRS resources in the third resource subset may be determined using steps 1 to 3 below:

[0210] Step 1: Initialize the third resource subset. On the OFDM symbol where the SL PRS resources included in the initialized third resource subset are located, the number of excluded SL PRS resources is less than or equal to i, where i is an integer greater than or equal to 0.

[0211] Step 2: Select SL PRS resources from the third resource subset.

[0212] Step 3. When there are no remaining SL PRS resources in the third resource subset, if the number of selected SL PRS resources is less than the first value, set i=i+1 and execute the step of selecting SL PRS resources from the third resource subset again until the number of selected SL PRS resources reaches the first value.

[0213] For example, the first value N+1, the above steps 1 to 3 can be implemented as follows:

[0214] Let i=0. At this time, the SL PRS resources included in the third resource subset are the same as the SL PRS resources included in the above-mentioned first resource subset. They are all located in the OFDM symbols, and there is no excluded SL PRS resource.

[0215] The SL PRS resource is selected from the third resource subset mentioned above.

[0216] When there are no remaining SL PRS resources in the above-mentioned third resource subset, if the number of selected SL PRS resources is less than N+1, let i=i+1=1. At this time, the SL PRS resources included in the third resource subset are SL PRS resources on the OFDM symbol where there is only one excluded SL PRS resource.

[0217] The SL PRS resource is selected from the third resource subset mentioned above.

[0218] When there are no remaining SL PRS resources in the above-mentioned third resource subset, if the number of selected SL PRS resources is still less than N+1, let i=i+1=2. At this time, the SL PRS resources included in the third resource subset are SL PRS resources on the OFDM symbol where there are only two excluded SL PRS resources.

[0219] The SL PRS resource is selected from the third resource subset mentioned above.

[0220] Resource selection stops until the number of selected SL PRS resources reaches N+1 or there are no remaining SL PRS resources in the resource pool.

[0221] Compared with the above method 3.2, the above method can better reduce the impact of internal leakage, but the implementation complexity is slightly higher.

[0222] 3.4. How to select resources in the above methods 3.1, 3.2 and 3.3

[0223] In some embodiments, when performing resource selection in the first resource subset, the second resource subset, and / or the third resource subset, at least one SL PRS resource is randomly selected.

[0224] In some embodiments, when selecting SL PRS resources on any OFDM symbol group, if there are excluded SL PRS resources on the OFDM symbol group, the SL PRS resource with the largest frequency domain interval from the excluded SL PRS resource is preferentially selected.

[0225] The frequency domain interval between SL PRS resources can be determined by the RE offset of the two SL PRS resources. The larger the difference in RE offset, the larger the frequency domain interval.

[0226] For example, one OFDM symbol includes four SL PRS resources with RE offsets of 0, 1, 2, and 3. At this time, if the SL PRS resource with an RE offset of 0 is occupied, the SL PRS resource with the largest frequency domain interval from the SL PRS resource is the SL PRS resource with an RE offset of 3. If the SL PRS resource with an RE offset of 2 is occupied, the SL PRS resource with the largest frequency domain interval from the SL PRS resource is the SL PRS resource with an RE offset of 0.

[0227] The above method can reduce the risk of in-band leakage to a certain extent. In addition, compared with the method in 3.3, it reduces the complexity of resource selection.

[0228] 4. SL PRS resource set is indicated by the upper layer

[0229] In some embodiments, at least one SL PRS resource is selected from the SL PRS resources indicated by the higher layer.

[0230] In some embodiments, the higher layer refers to a layer above the MAC layer, for example, the higher layer may be an SLPP (Sidelink Positioning Protocol) layer.

[0231] The higher layer can accurately select a suitable SL PRS resource set according to the positioning requirements, so that the selected SL PRS resources can ensure the positioning accuracy.

[0232] The following are device embodiments of the present application, which can be used to implement the method embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the method embodiments of the present application.

[0233] Please refer to Figure 11, which shows a block diagram of a resource selection device provided by one embodiment of the present application. This device has the function of implementing the above-mentioned resource selection method. The function can be implemented by hardware or by hardware executing corresponding software. The device can be the terminal device described above, or it can be set in a terminal device. As shown in Figure 11, the device 1100 may include: a selection module 1110.

[0234] The selection module 1110 is configured to select at least one SL PRS resource from a SL PRS resource set, where the SL PRS resource is used to send the SL PRS.

[0235] In some embodiments, the SL PRS resource set includes all SL PRS resources configured or pre-configured in a resource pool; or,

[0236] The SL PRS resource set includes SL PRS resources configured or pre-configured in a resource pool and within a first time domain range.

[0237] In some embodiments, the SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool; or,

[0238] The SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool and within the first time domain range.

[0239] In some embodiments, the first time domain range is from the current time domain unit to the last time domain unit before the remaining delay of the SL PRS.

[0240] In some embodiments, the number of OFDM symbols occupied by the SL PRS resources included in the SL PRS resource set is greater than or equal to a first threshold, and the comb tooth size is less than or equal to a second threshold;

[0241] or,

[0242] An effective comb tooth size of the SL PRS resource included in the SL PRS resource set is greater than or equal to a third threshold, where the effective comb tooth size is the product of the comb tooth size of the SL PRS resource and the number of OFDM symbols occupied by the SL PRS;

[0243] or,

[0244] The SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at the same position in different time domain units, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol;

[0245] or,

[0246] The SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at adjacent positions in different time domain units. One time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol.

[0247] In some embodiments, the selection module 1110 is configured to randomly select the at least one SL PRS resource from the SL PRS resource set.

[0248] In some embodiments, the SL PRS resource set is determined based on resource sensing.

[0249] In some embodiments, the selection module 1110 is configured to randomly select the at least one SL PRS resource from the SL PRS resource set.

[0250] In some embodiments, the selection module 1110 is used to preferentially select the at least one SL PRS resource from the first resource subset of the SL PRS resource set, and there are no excluded SL PRS resources on the OFDM symbols where the SL PRS resources included in the first resource subset are located.

[0251] In some embodiments, the selection module 1110 is also used to select at least one additional SL PRS resource from the second resource subset if the number of SL PRS resources selected from the first resource subset is less than a first value, and the second resource subset includes the SL PRS resources in the SL PRS resource set except the first resource subset.

[0252] In some embodiments, the selection module 1110 is configured to select the at least one SL PRS resource from a third resource subset of the SL PRS resource set, where the third resource subset is determined based on the number of excluded SL PRS resources on an OFDM symbol.

[0253] In some embodiments, the selection module 1110 is used to initialize the third resource subset, and the number of excluded SL PRS resources on the OFDM symbol where the SL PRS resources included in the initialized third resource subset are located is less than or equal to i, where i is an integer greater than or equal to 0; the SL PRS resources are selected from the third resource subset; when there are no remaining SL PRS resources in the third resource subset, if the number of selected SL PRS resources is less than the first value, set i=i+1, and execute the step of selecting the SL PRS resources from the third resource subset again until the number of selected SL PRS resources reaches the first value.

[0254] In some embodiments, when selecting SL PRS resources on any OFDM symbol group, if there are excluded SL PRS resources on the OFDM symbol group, the SL PRS resource with the largest frequency domain interval from the excluded SL PRS resource is preferentially selected.

[0255] In some embodiments, the selected SL PRS resources are multiple, and the multiple SL PRS resources include one SL PRS resource for initial transmission and at least one SL PRS resource for retransmission.

[0256] In some embodiments, the selected SL PRS resources are multiple, and the multiple SL PRS resources occupy OFDM symbol groups at the same position in different time domain units, or the multiple SL PRS resources occupy OFDM symbol groups at adjacent positions in different time domain units; wherein, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol.

[0257] In some embodiments, the time domain interval between the selected two adjacent SL PRS resources is greater than 0 and less than or equal to a fourth threshold.

[0258] The technical solution provided in the embodiment of the present application is that the terminal device selects at least one SL PRS resource in the SL PRS resource set. The number of candidate resources in the SL PRS resource set is large, which can effectively reduce resource collision or mutual interference with other terminal devices.

[0259] It should be noted that the device provided in the above embodiment only uses the division of the above-mentioned functional modules as an example to implement its functions. In actual applications, the above-mentioned functions can be assigned to different functional modules according to actual needs, that is, the content structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0260] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here. For details not described in detail in the embodiment of the device, reference can be made to the above method embodiment.

[0261] Please refer to FIG12 , which shows a schematic diagram of the structure of a terminal device provided by an embodiment of the present application. The terminal device 1200 may include: a processor 1201 , a transceiver 1202 , and a memory 1203 .

[0262] The processor 1201 includes one or more processing cores. The processor 1201 executes various functional applications and information processing by running software programs and modules.

[0263] The transceiver 1202 may include a receiver and a transmitter. For example, the receiver and the transmitter may be implemented as the same wireless communication component, which may include a wireless communication chip and a radio frequency antenna.

[0264] The memory 1203 may be connected to the processor 1201 and the transceiver 1202 .

[0265] The memory 1203 may be used to store a computer program executed by the processor, and the processor 1201 is used to execute the computer program to implement each step in the above method embodiment.

[0266] In an exemplary embodiment, the processor 1201 is configured to select at least one SL PRS resource from a SL PRS resource set, where the SL PRS resource is used to send the SL PRS.

[0267] For details not described in detail in this embodiment, please refer to the above embodiments and will not be described in detail here.

[0268] In addition, the memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: magnetic or optical disks, electrically erasable programmable read-only memory, erasable programmable read-only memory, static random access memory, read-only memory, magnetic memory, flash memory, and programmable read-only memory.

[0269] The embodiment of the present application also provides a computer-readable storage medium, wherein the storage medium stores a computer program, and the computer program is used to be executed by a processor to implement the above-mentioned resource selection method. In some embodiments, the computer-readable storage medium may include: ROM (Read-Only Memory), RAM (Random-Access Memory), SSD (Solid State Drives) or optical disks, etc. Among them, random access memory may include ReRAM (Resistance Random Access Memory) and DRAM (Dynamic Random Access Memory).

[0270] An embodiment of the present application further provides a chip, which includes a programmable logic circuit and / or program instructions, and is used to implement the above-mentioned resource selection method when the chip is running.

[0271] An embodiment of the present application also provides a computer program product, which includes computer instructions stored in a computer-readable storage medium. A processor reads and executes the computer instructions from the computer-readable storage medium to implement the above-mentioned resource selection method.

[0272] It should be understood that the "indication" mentioned in the embodiments of this application can be a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" can mean that A directly indicates B, for example, B can be obtained through A; it can also mean that A indirectly indicates B, for example, A indicates C, and B can be obtained through C; it can also mean that there is an association between A and B.

[0273] In the description of 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 being indicated, configuration and being configured, etc.

[0274] In some embodiments of the present application, "predefined" 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., including a terminal device and a network device), and the present application does not limit the specific implementation method. For example, predefined may refer to information defined in a protocol.

[0275] In some embodiments of the present application, the "protocol" may refer to a standard protocol in the field of communications, for example, it may include an LTE protocol, a NR protocol, and related protocols used in future communication systems, and this application does not limit this.

[0276] In this document, "plurality" refers to two or more. "And / or" describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. The character " / " generally indicates an "or" relationship between the associated objects.

[0277] The term “greater than or equal to” mentioned herein may mean greater than or equal to, or greater than, and the term “less than or equal to” may mean less than or equal to, or less than.

[0278] In addition, the step numbers described in this document only illustrate a possible execution order between the steps. In some other embodiments, the above steps may not be executed in the order of the numbers, such as two steps with different numbers are executed at the same time, or two steps with different numbers are executed in the opposite order of the diagram. The embodiments of the present application are not limited to this.

[0279] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0280] The above description is merely an exemplary embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A resource selection method, characterized in that: The method is performed by a terminal device, and the method includes: At least one SL PRS resource is selected from a sideline positioning reference signal SL PRS resource set, and the SL PRS resource is used to send the SL PRS.

2. The method according to claim 1, characterized in that The SL PRS resource set includes all SL PRS resources configured or pre-configured in the resource pool; or, The SL PRS resource set includes SL PRS resources configured or pre-configured in a resource pool and within a first time domain range.

3. The method according to claim 1, characterized in that The SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool; or, The SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool and within the first time domain.

4. The method according to claim 2 or 3, characterized in that: The first time domain range is from the current time domain unit to the last time domain unit before the remaining delay of the SL PRS.

5. The method according to claim 3, characterized in that: The number of orthogonal frequency division multiplexing OFDM symbols occupied by the SL PRS resources included in the SL PRS resource set is greater than or equal to a first threshold, and the comb tooth size is less than or equal to a second threshold; or, The effective comb tooth size of the SL PRS resource included in the SL PRS resource set is greater than or equal to a third threshold, and the effective comb tooth size is the product of the comb tooth size of the SL PRS resource and the number of OFDM symbols occupied by the SL PRS; or, The SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at the same position in different time domain units, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol; or, The SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at adjacent positions in different time domain units. One time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol.

6. The method according to any one of claims 2 to 5, characterized in that: The selecting at least one SL PRS resource from the SL PRS resource set comprises: The at least one SL PRS resource is randomly selected from the SL PRS resource set.

7. The method according to claim 1, characterized in that The SL PRS resource set is determined based on resource listening.

8. The method according to claim 7, characterized in that The selecting at least one SL PRS resource from the SL PRS resource set comprises: The at least one SL PRS resource is randomly selected from the SL PRS resource set.

9. The method according to claim 7, characterized in that: The selecting at least one SL PRS resource from the SL PRS resource set comprises: The at least one SL PRS resource is preferentially selected from the first resource subset of the SL PRS resource set, and no excluded SL PRS resources exist on the OFDM symbols where the SL PRS resources included in the first resource subset are located.

10. The method according to claim 9, characterized in that The method further comprises: If the number of SL PRS resources selected from the first resource subset is less than a first value, at least one SL PRS resource is additionally selected from a second resource subset, wherein the second resource subset includes the SL PRS resource set except the first resource subset. SL PRS resources outside of a resource subset.

11. The method according to claim 7, characterized in that The selecting at least one SL PRS resource from the SL PRS resource set comprises: The at least one SL PRS resource is selected from a third resource subset of the SL PRS resource set, and the third resource subset is determined according to the number of excluded SL PRS resources on the OFDM symbol.

12. The method according to claim 11, characterized in that The selecting the at least one SL PRS resource from the third resource subset of the SL PRS resource set comprises: Initialize the third resource subset, wherein the number of excluded SL PRS resources on the OFDM symbol where the SL PRS resources included in the initialized third resource subset are located is less than or equal to i, where i is an integer greater than or equal to 0; Selecting the SL PRS resource from the third resource subset; When there are no remaining SL PRS resources in the third resource subset, if the number of selected SL PRS resources is less than the first value, set i=i+1 and execute the step of selecting the SL PRS resources from the third resource subset again until the number of selected SL PRS resources reaches the first value.

13. The method according to any one of claims 9 to 12, characterized in that: When selecting SL PRS resources on any OFDM symbol group, if there are excluded SL PRS resources on the OFDM symbol group, the SL PRS resource with the largest frequency domain interval from the excluded SL PRS resource is preferentially selected.

14. The method according to any one of claims 1 to 13, characterized in that: The selected SL PRS resources are multiple, and the multiple SL PRS resources include one SL PRS resource for initial transmission and at least one SL PRS resource for retransmission.

15. The method according to any one of claims 1 to 14, characterized in that The selected SL PRS resources are multiple, and the multiple SL PRS resources occupy OFDM symbol groups at the same position in different time domain units, or the multiple SL PRS resources occupy OFDM symbol groups at adjacent positions in different time domain units; wherein, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol.

16. The method according to any one of claims 1 to 15, characterized in that The time domain interval between the selected two adjacent SL PRS resources is greater than 0 and less than or equal to a fourth threshold.

17. A resource selection device, characterized in that: The device comprises: The selection module is used to select at least one SL PRS resource from a sideline positioning reference signal SL PRS resource set, and the SL PRS resource is used to send the SL PRS.

18. The device according to claim 17, characterized in that The SL PRS resource set includes all SL PRS resources configured or pre-configured in the resource pool; or, The SL PRS resource set includes SL PRS resources configured or pre-configured in a resource pool and within a first time domain range.

19. The device according to claim 17, characterized in that The SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool; or, The SL PRS resource set includes part of the SL PRS resources configured or pre-configured in the resource pool and within the first time domain.

20. The device according to claim 18 or 19, characterized in that The first time domain range is from the current time domain unit to the last time domain unit before the remaining delay of the SL PRS.

21. The device according to claim 19, characterized in that The number of orthogonal frequency division multiplexing OFDM symbols occupied by the SL PRS resources included in the SL PRS resource set is greater than or equal to a first threshold, and the comb tooth size is less than or equal to a second threshold; or, The effective comb tooth size of the SL PRS resources included in the SL PRS resource set is greater than or equal to a third threshold, The effective comb tooth size is the product of the comb tooth size of the SL PRS resource and the number of OFDM symbols occupied by the SL PRS; or, The SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at the same position in different time domain units, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol; or, The SL PRS resources included in the SL PRS resource set occupy OFDM symbol groups at adjacent positions in different time domain units. One time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol.

22. The device according to any one of claims 18 to 21, characterized in that The selection module is used to randomly select at least one SL PRS resource from the SL PRS resource set.

23. The device according to claim 17, characterized in that The SL PRS resource set is determined based on resource listening.

24. The device according to claim 23, characterized in that The selection module is used to randomly select at least one SL PRS resource from the SL PRS resource set.

25. The device according to claim 23, characterized in that The selection module is used to preferentially select the at least one SL PRS resource from the first resource subset of the SL PRS resource set, and there is no excluded SL PRS resource on the OFDM symbol where the SL PRS resources included in the first resource subset are located.

26. The device according to claim 25, characterized in that The selection module is also used to select at least one additional SL PRS resource from the second resource subset if the number of SL PRS resources selected from the first resource subset is less than a first value, and the second resource subset includes SL PRS resources in the SL PRS resource set except the first resource subset.

27. The device according to claim 23, characterized in that The selection module is used to select the at least one SL PRS resource from a third resource subset of the SL PRS resource set, where the third resource subset is determined based on the number of SL PRS resources excluded on the OFDM symbol.

28. The device according to claim 27, characterized in that The selection module is used to initialize the third resource subset, and the number of excluded SL PRS resources on the OFDM symbol where the SL PRS resources included in the initialized third resource subset are located is less than or equal to i, where i is an integer greater than or equal to 0; select the SL PRS resources from the third resource subset; when there are no remaining SL PRS resources in the third resource subset, if the number of selected SL PRS resources is less than a first value, set i=i+1, and execute the step of selecting the SL PRS resources from the third resource subset again until the number of selected SL PRS resources reaches the first value.

29. The device according to any one of claims 25 to 28, characterized in that When selecting SL PRS resources on any OFDM symbol group, if there are excluded SL PRS resources on the OFDM symbol group, the SL PRS resource with the largest frequency domain interval from the excluded SL PRS resource is preferentially selected.

30. The device according to any one of claims 17 to 29, characterized in that The selected SL PRS resources are multiple, and the multiple SL PRS resources include one SL PRS resource for initial transmission and at least one SL PRS resource for retransmission.

31. The device according to any one of claims 17 to 30, characterized in that The selected SL PRS resources are multiple, and the multiple SL PRS resources occupy OFDM symbol groups at the same position in different time domain units, or the multiple SL PRS resources occupy OFDM symbol groups at adjacent positions in different time domain units; wherein, one time domain unit includes at least one OFDM symbol group, and each OFDM symbol group includes at least one OFDM symbol.

32. The device according to any one of claims 17 to 31, characterized in that The time domain interval between the selected two consecutive SL PRS resources is greater than 0 and less than or equal to a fourth threshold.

33. A terminal device, characterized in that: The terminal device comprises a processor and a memory, wherein a computer program is stored in the memory, and the processor executes the computer program to implement the method according to any one of claims 1 to 16.

34. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to be executed by a processor to implement the method according to any one of claims 1 to 16.

35. A chip, characterized in that: The chip comprises a programmable logic circuit and / or program instructions, and when the chip is running, it is used to implement the method according to any one of claims 1 to 16.

36. A computer program product, characterized in that The computer program product comprises computer instructions, which are stored in a computer-readable storage medium. A processor reads and executes the computer instructions from the computer-readable storage medium to implement the method according to any one of claims 1 to 16.

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