Resource determination method and apparatus for sidelink operation on unlicensed spectrum, and device

Abstract

The present application discloses a resource determination method and apparatus for sidelink operation on unlicensed spectrum, and a device. The method comprises: a first terminal device acquiring initial information; on the basis of the initial information, determining a candidate resource set; and performing resource exclusion on the candidate resource set to obtain an available resource set.

Description

Method, device and equipment for determining direct link resources operating in unlicensed frequency bands

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese Patent Application No. 202310869750.1 filed in China on July 14, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a method, apparatus, and device for determining sidelink resources operating in an unlicensed frequency band. Background Art

[0004] Sidelink is a communication method used between terminal devices. When a terminal device needs to communicate with another terminal device via Sidelink, it must first select Sidelink transmission resources. The selected Sidelink transmission resources are then used to establish Sidelink communication with the other terminal device. Current Sidelink resource selection mechanisms typically target licensed frequency bands.

[0005] However, the 3rd Generation Partnership Project (3GPP) introduced Sidelink Operation on Unlicensed Spectrum (SL-U). Compared to sidelink communications in licensed bands, devices operating in unlicensed bands can use any available spectrum without a license. However, due to the new features of SL-U, the sidelink resource selection mechanism used for licensed bands cannot be directly reused.

[0006] Based on this, in order to realize SL-U-based communication, ensure transmission efficiency and improve transmission reliability, it is urgent to provide a resource determination solution suitable for SL-U.

[0007] Summary of the Invention

[0008] The present application provides a method, apparatus, and device for determining sidelink resources operating in an unlicensed frequency band. The sidelink resource determination mechanism fully considers the characteristics of the SL-U, prepares for selecting reasonable SL-U resources, and makes it possible to use the SL-U for effective communication.

[0009] In a first aspect, the present application provides a method for determining direct link resources operating in an unlicensed frequency band, which is applied to a first terminal device, including:

[0010] Get initial information;

[0011] Determining a set of candidate resources based on the initial information;

[0012] Eliminate resources from the candidate resource set to obtain an available resource set.

[0013] Optionally, the method may further include:

[0014] A target resource is selected from the set of available resources.

[0015] Optionally, the initial information includes at least one of the following information:

[0016] Available resource block set (RB set);

[0017] Unavailable RB set;

[0018] RB sets that failed to listen before talk (LBT) continuously;

[0019] Time information corresponding to the RB set of consecutive LBT failures;

[0020] The number of RB sets occupied by Physical Sidelink Control Channel (PSCCH) and / or Physical Sidelink Shared Channel (PSSCH) transmissions within a time unit;

[0021] The set of RBs occupied by PSCCH and / or PSSCH transmissions within a time unit;

[0022] The number of subchannels occupied by PSCCH and / or PSSCH transmissions within a time unit;

[0023] The number of subchannels occupied by PSCCH and / or PSSCH transmission in one RB set within one time unit;

[0024] The starting physical resource block (PRB) of the resource pool.

[0025] Optionally, the available RB set satisfies at least one of the following conditions:

[0026] The available RB set is a continuous RB set in the frequency domain;

[0027] The available RB set does not include an RB set with consecutive LBT failures;

[0028] The number of RB sets in any combination of consecutive RB sets in the available RB sets is greater than or equal to the number of RB sets occupied by PSSCH and / or PSCCH transmission.

[0029] Optionally, the RB set occupied by PSCCH and / or PSSCH transmission within the one time unit satisfies at least one of the following conditions:

[0030] The RB set occupied by the PSCCH and / or PSSCH transmission within the one time unit is a continuous RB set in the frequency domain;

[0031] The RB set occupied by PSCCH and / or PSSCH transmission within the one time unit does not include the RB set with continuous LBT failures.

[0032] Optionally, the resources in the candidate resource set need to meet at least one of the following conditions:

[0033] Located in one of the time units in the time domain;

[0034] A first number of RB sets are included in the frequency domain, wherein each RB set occupies a second number of sub-channels.

[0035] Optionally, the first quantity and / or the second quantity needs to meet at least one of the following conditions:

[0036] The product of the first number and the second number is equal to the number of subchannels occupied by PSCCH / PSSCH transmission;

[0037] The second number of sub-channels are continuous sub-channels;

[0038] The indexes of the second number of sub-channels occupied by different RB sets in the first number of RB sets are the same;

[0039] The first number of RB sets are continuous RB sets;

[0040] The first number of RB sets does not include any unavailable RB set in the initial information;

[0041] The first number of RB sets does not include any RB set with consecutive LBT failures in the initial information;

[0042] The first number is equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission in one time unit in the initial information;

[0043] The first number of RB sets is the RB sets occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information.

[0044] Optionally, determining a candidate resource set based on the initial information includes:

[0045] Based on at least one of the initial information, the target time and the target frequency domain, the candidate resource set is determined, the resources in the candidate resource set belong to the target time in the time domain, and the resources in the candidate resource set belong to the target frequency domain in the frequency domain.

[0046] Optionally, the target frequency domain satisfies at least one of the following conditions:

[0047] The target frequency domain is an RB set occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information;

[0048] The target frequency domain is a third number of continuous RB sets in the resource pool, where the third number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission;

[0049] The target frequency domain is a set of all target type RB sets in the resource pool, and the target type RB set set includes a fourth number of consecutive RB sets, and the fourth number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission.

[0050] Optionally, the target frequency domain resources do not include an RB set in at least one of the following situations:

[0051] The RB set of consecutive LBT failures in the initial information;

[0052] A fifth number of consecutive RB sets, where the fifth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmission.

[0053] An independent RB set, where the independent RB set does not form a continuous RB set with any other RB set in the resource pool.

[0054] Optionally, excluding resources from the candidate resource set to obtain an available resource set includes:

[0055] The target class candidate resources are excluded from the candidate resource set to obtain the available resource set, where the target class candidate resources are located in a target RB set.

[0056] Optionally, the target RB set satisfies at least one of the following conditions:

[0057] The target RB set is the RB set with consecutive LBT failures in the initial information;

[0058] The target RB set is an unavailable RB set in the initial information;

[0059] The target RB set is a sixth number of consecutive RB sets, where the sixth number is smaller than the number of RB sets occupied by PSCCH and / or PSSCH transmission;

[0060] The target RB set is an independent RB set, and the independent RB set does not form a continuous RB set with any other RB set in the resource pool.

[0061] Optionally, a ratio of the number of resources in the available resource set to the number of resources in the first resource set is greater than or equal to a first threshold, wherein the first resource set is any one of the following:

[0062] The first resource set is all candidate resources in the resource selection window;

[0063] The first resource set is all candidate resources in the resource selection window except the target class candidate resources.

[0064] Optionally, the method further includes:

[0065] A channel busy ratio (CBR) is obtained, where the CBR is a ratio of the number of sub-channels whose received signal strength indicator (RSSI) exceeds a second threshold to the number of all sub-channels in the resource selection window.

[0066] Optionally, the RSSI is defined in any one of the following ways:

[0067] The RSSI is the linear average of all received powers on the orthogonal frequency division multiplexing OFDM symbols configured for PSCCH and PSSCH in a time slot, excluding the start symbol;

[0068] The RSSI is the maximum value of at least two values ​​among the first value, the second value, and the third value, wherein the first value is the linear average value of the received power on all symbols between the first starting symbol and the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot; the second value is the linear average value of the received power on all symbols after the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot; and the third value is the linear average value of the received power on all symbols except the first starting symbol and the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot.

[0069] Optionally, the frequency domain range of the target measurement window is at least one of the following:

[0070] The frequency domain range of the resource pool;

[0071] RB sets in the resource pool except the unavailable RB set in the initial information;

[0072] RB sets in the resource pool except the RB sets with consecutive LBT failures in the initial information.

[0073] In a second aspect, the present application further provides a device for determining direct link resources operating in an unlicensed frequency band, which is applied to a first terminal device, including:

[0074] an acquisition unit, used for acquiring initial information;

[0075] a determining unit, configured to determine a set of candidate resources based on the initial information;

[0076] The obtaining unit is configured to exclude resources from the candidate resource set to obtain an available resource set.

[0077] Optionally, the device further comprises:

[0078] The selection unit is configured to select a target resource from the set of available resources.

[0079] Optionally, the initial information includes at least one of the following information:

[0080] Available RB sets;

[0081] Unavailable RB set;

[0082] RB set with consecutive LBT failures;

[0083] Time information corresponding to the RB set of consecutive LBT failures;

[0084] The number of RB sets occupied by PSCCH and / or PSSCH transmission in one time unit;

[0085] The set of RBs occupied by PSCCH and / or PSSCH transmissions within a time unit;

[0086] The number of subchannels occupied by PSCCH and / or PSSCH transmissions within a time unit;

[0087] The number of subchannels occupied by PSCCH and / or PSSCH transmission in one RB set within one time unit;

[0088] The starting PRB of the resource pool.

[0089] Optionally, the available RB set satisfies at least one of the following conditions:

[0090] The available RB set is a continuous RB set in the frequency domain;

[0091] The available RB set does not include an RB set with consecutive LBT failures;

[0092] The number of RB sets in any combination of consecutive RB sets in the available RB sets is greater than or equal to the number of RB sets occupied by PSSCH and / or PSCCH transmission.

[0093] Optionally, the RB set occupied by PSCCH and / or PSSCH transmission within the one time unit satisfies at least one of the following conditions:

[0094] The RB set occupied by the PSCCH and / or PSSCH transmission within the one time unit is a continuous RB set in the frequency domain;

[0095] The RB set occupied by PSCCH and / or PSSCH transmission within the one time unit does not include the RB set with continuous LBT failures.

[0096] Optionally, the resources in the candidate resource set need to meet at least one of the following conditions:

[0097] Located in one of the time units in the time domain;

[0098] A first number of RB sets are included in the frequency domain, wherein each RB set occupies a second number of sub-channels.

[0099] Optionally, the first quantity and / or the second quantity needs to meet at least one of the following conditions:

[0100] The product of the first number and the second number is equal to the number of subchannels occupied by PSCCH / PSSCH transmission;

[0101] The second number of sub-channels are continuous sub-channels;

[0102] The indexes of the second number of sub-channels occupied by different RB sets in the first number of RB sets are the same;

[0103] The first number of RB sets are continuous RB sets;

[0104] The first number of RB sets does not include any unavailable RB set in the initial information;

[0105] The first number of RB sets does not include any RB set with consecutive LBT failures in the initial information;

[0106] The first number is equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission in one time unit in the initial information;

[0107] The first number of RB sets is the RB sets occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information.

[0108] Optionally, the determining unit is specifically configured to:

[0109] Based on at least one of the initial information, the target time and the target frequency domain, the candidate resource set is determined, the resources in the candidate resource set belong to the target time in the time domain, and the resources in the candidate resource set belong to the target frequency domain in the frequency domain.

[0110] Optionally, the target frequency domain satisfies at least one of the following conditions:

[0111] The target frequency domain is an RB set occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information;

[0112] The target frequency domain is a third number of continuous RB sets in the resource pool, where the third number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission;

[0113] The target frequency domain is a set of all target type RB sets in the resource pool, and the target type RB set set includes a fourth number of consecutive RB sets, and the fourth number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission.

[0114] Optionally, the target frequency domain resources do not include an RB set in at least one of the following situations:

[0115] The RB set of consecutive LBT failures in the initial information;

[0116] A fifth number of consecutive RB sets, where the fifth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmission.

[0117] An independent RB set, where the independent RB set does not form a continuous RB set with any other RB set in the resource pool.

[0118] Optionally, the obtaining unit is specifically configured to:

[0119] The target class candidate resources are excluded from the candidate resource set to obtain the available resource set, where the target class candidate resources are located in a target RB set.

[0120] Optionally, the target RB set satisfies at least one of the following conditions:

[0121] The target RB set is the RB set with consecutive LBT failures in the initial information;

[0122] The target RB set is an unavailable RB set in the initial information;

[0123] The target RB set is a sixth number of consecutive RB sets, where the sixth number is smaller than the number of RB sets occupied by PSCCH and / or PSSCH transmission;

[0124] The target RB set is an independent RB set, and the independent RB set does not form a continuous RB set with any other RB set in the resource pool.

[0125] Optionally, a ratio of the number of resources in the available resource set to the number of resources in the first resource set is greater than or equal to a first threshold, wherein the first resource set is any one of the following:

[0126] The first resource set is all candidate resources in the resource selection window;

[0127] The first resource set is all candidate resources in the resource selection window except the target class candidate resources.

[0128] Optionally, the device further comprises:

[0129] The calculation unit is configured to obtain a CBR, where the CBR is a ratio of the number of sub-channels whose RSSI exceeds a second threshold to the number of all sub-channels in the resource selection window.

[0130] Optionally, the RSSI is defined in any one of the following ways:

[0131] The RSSI is the linear average of all received powers on orthogonal frequency division multiplexing (OFDM) symbols configured for PSCCH and PSSCH in a time slot, excluding the start symbol, where the start symbol may be 1 symbol or 2 symbols.

[0132] The RSSI is the maximum value of at least two values ​​among the first value, the second value, and the third value, wherein the first value is the linear average value of the received power on all symbols between the first starting symbol and the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot; the second value is the linear average value of the received power on all symbols after the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot; and the third value is the linear average value of the received power on all symbols except the first starting symbol and the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot.

[0133] Optionally, the frequency domain range of the target measurement window is at least one of the following:

[0134] The frequency domain range of the resource pool;

[0135] RB sets in the resource pool except the unavailable RB set in the initial information;

[0136] RB sets in the resource pool except the RB sets with consecutive LBT failures in the initial information.

[0137] In a third aspect, the present application further provides a terminal device, comprising a processor and a memory:

[0138] The memory is used to store programs;

[0139] The processor is used to execute the method provided in the first aspect according to the program.

[0140] In a fourth aspect, the present application further provides a storage medium, which is used to store a program, and the program runs on a processor to execute the method provided in the first aspect above.

[0141] It can be seen that this application has the following beneficial effects:

[0142] The present application provides a method for determining direct link resources operating in an unlicensed frequency band. If a first terminal device has a need to communicate with a second terminal device via SL-U, the method can be executed to select transmission resources based on SL-U. In the method, first, the first terminal device obtains initial information; then, the first terminal device determines a set of candidate resources based on the initial information; then, the first terminal device excludes resources from the set of candidate resources to obtain a set of available resources. In this way, the first terminal device can select a target resource from the set of available resources, so that the first terminal device can perform SL-U communication with the second terminal device based on the target resource. It can be seen that this method overcomes the problem of not being able to directly use the Sidelink resource selection scheme for the licensed frequency band, fully considers the characteristics of SL-U in the resource determination process, and provides a method for determining an available resource set suitable for SL-U, making preparations for selecting target transmission resources, making it possible for terminal devices to use SL-U for effective communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0143] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0144] FIG1 is a schematic diagram showing the correspondence between subchannels, IRBs, and PRBs;

[0145] FIG2 is a flow chart of a method for determining direct link resources operating in an unlicensed frequency band according to an embodiment of the present application;

[0146] FIG3 is a schematic diagram of an RB set in initial information according to an embodiment of the present application;

[0147] FIG4 is a schematic diagram of time information of consecutive LBT failures according to an embodiment of the present application;

[0148] FIG5 is a schematic diagram of candidate single-slot resources in an embodiment of the present application;

[0149] FIG6 is another schematic diagram of candidate single-slot resources according to an embodiment of the present application;

[0150] FIG7 is a schematic diagram of symbols within a time slot according to an embodiment of the present application;

[0151] FIG8 is a schematic structural diagram of a device for determining direct link resources operating in an unlicensed frequency band according to an embodiment of the present application;

[0152] FIG9 is a schematic structural diagram of a terminal device in an embodiment of the present application. DETAILED DESCRIPTION

[0153] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the following further describes the embodiments of the present application in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present application and are not intended to limit the present application. In addition, it should be noted that, for ease of description, the drawings only show portions relevant to the present application, not all structures.

[0154] Terminal devices operating in the unlicensed spectrum band need to meet the restrictions of occupied channel bandwidth (OCB) and power spectral density (PSD). Therefore, the interlaced resource block (IRB) structure is introduced in the new radio on unlicensed spectrum (NR-U) operating in the unlicensed spectrum band. In the SL-U mechanism, the transmission of PSCCH and PSSCH supports the IRB structure. In addition, the SL-U system based on the IRB structure adopts the concept of subchannel in R16 / R17, which is the minimum granularity of PSSCH transmission. A subchannel is defined as one or more IRBs. Therefore, the subchannel is no longer composed of continuous PRBs in the frequency domain. The R16 / R17 resource allocation mechanism is designed for subchannels based on continuous PRBs and is not applicable to the IRB-based SL-U system.

[0155] The relationship between subchannels, IRBs, and PRBs in SL-U can be understood as follows: a subchannel is defined within an RB set, and one subchannel is equal to K IRBs, that is, one subchannel is equal to K IRBs within an RB set; the PRBs included in an IRB indexed by m can be expressed as {m+M, m+2M, m+3M, ...}, that is, one IRB includes multiple PRBs, and the interval between PRBs is M. Specifically, for a subcarrier spacing of 15 kilohertz (kHz), M is equal to 10, and K can be equal to 1 or 2; for a subcarrier spacing of 30 kHz, M is equal to 5, and K can be equal to 1; m∈{0,1,…,M-1}. Taking M=5 as an example, the relationship between IRB, PRB and subchannel can be shown in Figure 1, where there is only one RB set in the resource pool, including 5 IRBs with indexes: 0, 1, 2, 3, 4, and the corresponding PRB indexes are: 0, 1, 2, 3, 4, ..., 48, 49. Then, if K=2, subchannel 0 includes IRB 0 and IRB 1 in the RB set, and subchannel 1 includes IRB 2 and IRB 3 in the RB set; if K=1, subchannel 0 includes IRB 0 in the RB set, and subchannel 1 includes IRB 1 in the RB set.

[0156] In order to ensure that SL-U can be widely used, an embodiment of the present application provides a resource determination method suitable for SL-U, which introduces the characteristics of SL-U, such as the RB set for detecting continuous LBT failures, the physical layer structure based on IRB, the definition of sub-channels, etc., and improves the resource allocation mechanism of the direct link, so that the resources in the determined available resource set are suitable for SL-U communication. In this method, first, the first terminal device obtains initial information; then, the first terminal device determines the candidate resource set based on the initial information; then, the first terminal device excludes resources from the candidate resource set to obtain an available resource set. If the first terminal device has a need to communicate with the second terminal device through SL-U, the above-mentioned initial information can be the configuration information of the resource pool and / or the parameter information required for SL-U communication, etc.; moreover, after obtaining the available resource set, the target resource can also be selected from the available resource set, so that the first terminal device can perform SL-U communication with the second terminal device based on the target resource. It can be seen that this method overcomes the problem of not being able to directly use the Sidelink resource selection scheme for the authorized frequency band. It can fully consider the characteristics of SL-U in the resource determination process, and provides a method for determining the available resource set suitable for SL-U, which prepares for the selection of target transmission resources and makes it possible for terminal devices to use SL-U for effective communication.

[0157] It should be noted that the subject implementing the method for determining direct link resources operating in an unlicensed frequency band may be the device for determining direct link resources operating in an unlicensed frequency band provided in an embodiment of the present application, and the device for determining direct link resources operating in an unlicensed frequency band may be carried in a terminal device or a functional module of the terminal device. The terminal device mentioned above may be any device capable of implementing the method for determining direct link resources operating in an unlicensed frequency band in an embodiment of the present application, for example, a terminal device may be a smartphone, a vehicle-mounted terminal, or the like.

[0158] It should be noted that when each terminal device has the need to communicate with other terminal devices via Sidelink, the terminal device can serve as the first terminal device in the embodiment of the present application, and take the other party as the second terminal device, execute the method provided in the embodiment of the present application, and determine the available resource set that can select reasonable resources when communicating with the other party using SL-U.

[0159] To facilitate understanding of the specific implementation of the direct link resource selection method for operating in an unlicensed frequency band provided in an embodiment of the present application, the following will be described with reference to the accompanying drawings.

[0160] Figure 2 is a flow chart of a method for determining direct link resources operating in an unlicensed frequency band, provided in an embodiment of the present application. As shown in Figure 2, the method can be applied to a first terminal device and is suitable for determining a set of available resources for sidelink communication with a second terminal device when the first terminal device needs to communicate with the second terminal device via sidelink.

[0161] As shown in FIG2 , the method may include, for example, S101 to S103:

[0162] S101, obtaining initial information.

[0163] Initial information refers to the information required for the first terminal device and the second terminal device to perform SL-U communication, including but not limited to resource pool configuration information and / or transmission parameter information. The initial information can be a high-level (media access control (MAC) layer or radio resource control (RRC) layer, etc.) configuration of the first terminal device, a base station configuration, a high-level indication, predefined or preconfigured.

[0164] As an example, the initial information may include at least one of the following information: (1) available RB sets; (2) unavailable RB sets; (3) RB sets with consecutive LBT failures; (4) time information corresponding to RB sets with consecutive LBT failures; (5) the number of RB sets occupied by PSCCH and / or PSSCH transmissions within a time unit; (6) the RB sets occupied by PSCCH and / or PSSCH transmissions within a time unit; (7) the number of subchannels occupied by PSCCH and / or PSSCH transmissions within a time unit; (8) the number of subchannels occupied by PSCCH and / or PSSCH transmissions within a RB set within a time unit; and (9) the starting PRB of the resource pool.

[0165] Optionally, the initial information may also include at least one of the following information: (10) resource pool; (11) layer 1 (L1) priority; (12) remaining service packet transmission delay; (13) resource reservation interval (or resource reservation cycle); (14) resource set that may be re-evaluated and / or preempted; (15) resource selection mechanism indication.

[0166] For (1) in the initial information, it can refer to the available RB set in the resource pool, or the frequency domain range of the resource selection window, or the available RB set in the resource selection window, or the RB set available for PSCCH and PSSCH transmission, that is, the definition of candidate resources, the initialization of candidate resource sets, the available resource sets, and the transmission resources of PSCCH and PSSCH need to be located in these RB sets. In particular, for multiple transmissions of a transport block (TB), or a transmission and its subsequent scheduled transmissions, each transmission needs to be located in these RB sets. It should be noted that the RB set in (1) needs to be a continuous RB set in the frequency domain or a continuous index.

[0167] In specific implementation, (1) can be determined by a higher layer (e.g., MAC layer) of the first terminal device and sent to the physical layer of the first terminal device; or, (1) can also be determined by the physical layer of the first terminal device. Taking the higher layer determining (1) as an example, for example, an RB set that satisfies at least one of the following conditions can be used as an available RB set: Condition 11, the available RB set is a continuous RB set in the frequency domain; Condition 12, the available RB set does not include RB sets with continuous LBT failures; Condition 13, the number of RB sets in any combination of continuous RB sets in the available RB set is greater than or equal to the number of RB sets required for PSSCH and / or PSCCH transmission (or, MAC protocol data unit (PDU)). In Condition 11, the available RB set is a continuous RB set in the frequency domain, which can refer to the continuous index of the RB set. Here, "RB set" can also be expressed as "RB set(s)", indicating an RB set set, which includes one or more RB sets. If there are multiple RB sets, these multiple RB sets are required to be continuous in the frequency domain; or, there can be only one RB set available.

[0168] It is understandable that when determining available RB sets, the higher layer needs to consider whether there are RB sets with detected consecutive LBT failures. The ultimate goal is to indicate that the RB sets do not include RB sets with detected consecutive LBT failures. As shown in Figure 3, RB set #3 and RB set #5 indicate RB sets with detected consecutive LBT failures. Therefore, the available RB sets indicated by the higher layer may include: RB set #0, RB set #1, RB set #2, RB set #4, RB set #6, and RB set #7. If it is considered that the available RB sets can be used for PSCCH and / or PSSCH transmission, that is, the above condition 13 (any combination of consecutive RB sets in Figure 3 includes 3, namely RB set#0+RB set#1+RB set#2, RB set#4 and RB set#6+RB set#7, that is, any combination of consecutive RB sets here represents the combination of the largest number of consecutive RB sets, for example, RB set#0+RB set+1 cannot be called a combination of consecutive RB sets), and the RB sets in the available RB sets need to be consecutive, assuming that PSCCH and / or PSSCH transmission needs to occupy 2 RB sets, then the available RB sets determined by the higher layer can be RB set#0, RB set#1, RB set#2, RB set#6 and RB set#7, among which RB set#0, RB set#1 and RB set#2 represent the first subset, RB set#6 and RB set#7 represent the second subset, and RB set#4 has only one RB set and does not form a continuous RB set with other RB sets. It cannot meet the transmission of PSCCH and / or PSSCH, so it is not used as an available RB. The contents of the set.

[0169] The initial information (2) may refer to an unavailable RB set in the resource pool, indicating an RB set that cannot be used during resource selection. (2) may also be described as: an unavailable RB set in the resource pool, or an RB set that is determined to be unavailable for the initialization resource set, or an RB set that cannot be used for PSCCH and / or PSSCH transmission.

[0170] Regarding (3) in the initial information, it may refer to an RB set in which a continuous LBT failure (Consistent LBT failure) is detected in the resource pool, and the RB set may belong to an unavailable RB set.

[0171] For (4) in the initial information, at least one of the following items may be included: the start time corresponding to the RB set of continuous LBT failure, the duration corresponding to the RB set of continuous LBT failure, or the end time corresponding to the RB set of continuous LBT failure. (3) and (4) may be combined to determine the unavailable RB set and the time period in which the RB set is unavailable. As an example, if the resource selection window determined by the first terminal device is as shown in FIG4 , including [n+T1, n+T2] in the time domain and RB set#0 and RB set#1 in the frequency domain, and the RB set of continuous LBT failure is detected to be RB set#1, the start time corresponding to the RB set of continuous LBT failure is n-10, and the duration corresponding to the continuous LBT failure is 20 time slots, that is, the end time is n+10, then it can be determined that RB set#1 in the time period from n+T1 to n+10 in the resource selection window is unavailable.

[0172] For (5) in the initial information, for example, when the result of (5) is 2, it means that a single PSCCH and / or PSSCH transmission needs to be located in 2 RB sets, or it means that a single time slot candidate resource needs to be located in 2 RB sets, but the positions of the two RB sets may not be fixed, and may be RB set#0+RB set#1 or RB set#1+RB set#2 in the resource pool. In addition, the two RB sets also need to be continuous, that is, (5) can be expressed as the number of continuous RB sets occupied by the transmission of PSCCH and / or PSSCH in one time unit. (5) can mean that any transmission of a transport block (TB) needs to occupy 2 RB sets, or that each transmission in the initial transmission and the scheduled PSCCH and / or PSSCH transmission needs to occupy 2 RB sets, or that the MAC PDU needs to occupy 2 RB sets.

[0173] In a specific implementation, (5) may be determined by a high-level layer of the first terminal device and sent to a physical layer of the first terminal device; or, (5) may also be determined by a physical layer of the first terminal device. Taking the high-level layer determining (5) as an example, for example, the RB sets counted by (5) may consider at least one of the following factors: the total number of RB sets configured in the resource pool, the RB sets in which consecutive LBT failures are detected, the number of subchannels occupied by PSCCH and / or PSSCH transmissions, the number of subchannels occupied by PSCCH and / or PSSCH transmissions in one RB set, the number of consecutive RB sets occupied by PSCCH and / or PSSCH transmissions, and the number of subchannels occupied by PSCCH and / or PSSCH transmissions in different RB sets being used being the same and having the same subchannel index. For example, still referring to FIG3 , PSCCH and / or PSSCH transmissions occupy 4 subchannels and occupy at least 1 subchannel in one RB set. Therefore, PSCCH and / or PSSCH transmissions are located in at most 4 RB sets. Considering that the number and index of subchannels occupied in different RB sets are the same, and PSCCH and / or PSSCH transmissions occupy continuous RB sets, it is determined that the number of RB sets in (5) can only be 1 or 2.

[0174] For (6) in the initial information, for example, when the result of (6) is RB set #1 and RB set #2, it can indicate that a single PSCCH and / or PSSCH transmission needs to be located in these two RB sets, or that a single time slot candidate resource needs to be located in these two RB sets, or that any transmission in a TB needs to be located in these two RB sets, or that the initial transmission and its reserved retransmission resources need to be located in these two RB sets, or that the transmission of MAC PDU needs to be located in these two RB sets, and these two RB sets need to be continuous.

[0175] In specific implementation, (6) can be determined by the upper layer of the first terminal device and sent to the physical layer of the first terminal device; or, (6) can also be determined by the physical layer of the first terminal device. Taking the determination of (6) by the upper layer as an example, for example, an RB set that satisfies at least one of the following conditions can be used as the content of (6): Condition 21, the RB sets occupied by PSCCH and / or PSSCH transmission in the said time unit are continuous RB sets in the frequency domain; Condition 22, the RB sets occupied by PSCCH and / or PSSCH transmission in the said time unit do not include RB sets with continuous LBT failures. Condition 23, the number of RB sets occupied by PCCH and / or PSSCH transmission in the said time unit is equal to the number of RB sets required for PSCCH and / or PSSCH transmission. Condition 24: The number of RB sets in any continuous RB set combination among the RB sets occupied by PSCCH and / or PSSCH transmission in the said time unit is greater than or equal to the number of RB sets required for PSCCH and / or PSSCH transmission. In condition 21, RB sets that are continuous in the frequency domain may refer to RB set indices that are continuous. Here, "RB set" may also be expressed as "RB set(s)", indicating an RB set set, which includes one or more RB sets. If there are multiple RB sets, these multiple RB sets are required to be continuous in the frequency domain; alternatively, there may be only one available RB set.

[0176] It is understandable that when the upper layer determines the RB set in (6), it needs to consider: the total number of RB sets configured in the resource pool, the RB set in which continuous LBT failures are detected, the number of subchannels occupied by PSCCH and / or PSSCH transmissions, the number of subchannels occupied by PSCCH and / or PSSCH transmissions in one RB set, the number of consecutive RB sets occupied by PSCCH and / or PSSCH transmissions, and the number of subchannels occupied by PSCCH and / or PSSCH transmissions in different RB sets used and the same subchannel index. Still as shown in Figure 3, PSCCH and / or PSSCH transmissions occupy 4 subchannels and occupy at least 1 RB set in one RB set, that is, PSCCH and / or PSSCH transmissions are located in at most 4 RB sets. In addition, considering that the number of subchannels occupied and the index are the same in different RB sets, and PSCCH and / or PSSCH transmissions occupy consecutive RB sets. When the number of RB sets occupied by PSCCH and / or PSSCH transmission can be 1, the (6) determined by the upper layer includes: RB set #0, RB set #1, RB set #2, RB set #4, RB set #6 and RB set #7. When the number of RB sets occupied by PSCCH and / or PSSCH transmission can be 2, the (6) determined by the upper layer includes: RB set #0 + RB set #1, RB set #1 + RB set #2, RB set #6 + RB set #7. That is, the indicated RB sets as a whole can be non-continuous, but any combination of continuous RB sets can meet the requirements of PSCCH and / or PSSCH transmission. In addition, the upper layer can also randomly select one from the above three combinations to indicate to the physical layer, such as RB set #0 + RB set #1. In this case, it means that the RB sets are continuous and can meet the requirements of PSCCH and / or PSSCH transmission.

[0177] For (7) in the initial information, it can be described as the number of subchannels occupied by PSCCH and / or PSSCH transmission in a time slot in all used RB sets, or the number of subchannels occupied by a single PSCCH and / or PSSCH transmission in all used RB sets.

[0178] For (8) in the initial information, in one case, the subchannels occupied by PSCCH and / or PSSCH in each RB set may be continuous; or, in another case, the subchannels occupied by PSCCH and / or PSSCH in each RB set may also be non-continuous.

[0179] It should be noted that in (5) to (8) of the initial information, the time unit may be a subframe, a time slot, a partial time slot, a symbol or a combination of multiple symbols.

[0180] It should be noted that in (5) to (8) of the initial information, "PSCCH and / or PSSCH transmission within a time unit" can also be understood or described as: a single PSCCH and / or PSSCH transmission, any PSCCH and / or PSSCH transmission in a TB, the initial transmission and the scheduled PSCCH and / or PSSCH transmission.

[0181] For (9) in the initial information, it can be described as the starting PRB in the first RB set in the resource pool, or it can be described as the starting PRB of the first subchannel in the first RB set in the resource pool, or it can be described as the starting PRB of the first subchannel in the resource pool, where the first subchannel refers to the lowest subchannel in the frequency domain, not the subchannel with the smallest index.

[0182] It should be noted that in order to determine the available RB set, the number of RB sets or the occupied RB set in the initial information, at least one of the following factors needs to be considered: the total number of RB sets configured in the resource pool, the RB set in which continuous LBT failures are detected, the number of subchannels occupied by PSCCH and / or PSSCH transmission, the number of subchannels occupied by PSCCH and / or PSSCH transmission in one RB set, the continuous RB sets occupied by PSCCH and / or PSSCH transmission, the number of subchannels occupied by PSCCH and / or PSSCH transmission in different RB sets used and the same subchannel index.

[0183] For (10) in the initial information, it is used to indicate the scope of resource selection, and resource selection is performed in this resource pool. For (15) in the initial information, it can include full sensing, partial sensing, random resource selection, and any combination thereof.

[0184] In some implementations, the initial information may be information for PSCCH and / or PSSCH transmission provided by the upper layer of the first terminal device to the physical layer at the moment of resource selection triggering.

[0185] It can be seen that the first terminal device obtains the initial information based on S101, which provides a reliable data basis for subsequent SL-U selection of reasonable resources. S101 can be, for example, an operation performed by the physical layer of the first terminal device.

[0186] S102: Determine a candidate resource set based on the initial information.

[0187] The candidate resource set can be understood as an initial candidate resource set determined in a resource pool or resource selection window, which is used for subsequent resource exclusion and determination of the final available resource set. In the embodiment of the present application, the following three possible ways of determining the candidate resource set are provided.

[0188] In a first possible implementation, the candidate resource set determined by S102 may also be represented as a set of candidate single-slot resources. S102 may, for example, include: determining the candidate resource set based on at least one of the initial information, the target time, and the target frequency domain, wherein the resources in the candidate resource set are located in one of the time units in the time domain, and the resources in the candidate resource set are located in a first number of RB sets in the frequency domain, wherein each RB set includes a second number of subchannels.

[0189] Among them, the resources in the candidate resource set need to meet at least one of the following conditions: Condition 31, the product of the first number and the second number is equal to the number of subchannels occupied by PSCCH / PSSCH transmission; Condition 32, the second number of subchannels are continuous subchannels; Condition 33, the indexes of the second number of subchannels occupied in different RB sets in the first number of RB sets are the same; Condition 34, the first number of RB sets are continuous RB sets; Condition 35, the first number of RB sets does not contain any unavailable RB sets in the initial information; Condition 36, the first number of RB sets does not contain any RB sets with continuous LBT failures in the initial information; Condition 37, the first number is equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information; Condition 38, the first number of RB sets are the RB sets occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information; Condition 39, the first number of RB sets are all or part of the RB sets in the available RB sets in the initial information.

[0190] It is understandable that the candidate resources in the candidate resource set can be understood as being located in one time unit in the time domain and in N RB sets in the frequency domain, each RB set including M subchannels. Determining the candidate resources is equivalent to determining N and M. N and M correspond to the first and second quantities in the above description, respectively.

[0191] As an example, assume that the transmission of the first terminal device needs to occupy 2 sub-channels and is located in 2 consecutive RB sets, that is, the transmission of the first terminal device needs to occupy 2 consecutive RB sets, occupying 1 sub-channel in each RB set, and the indexes of the 2 occupied sub-channels need to be the same, for example, sub-channel 1 and sub-channel 2 are occupied in the first RB set, and sub-channel 1 and sub-channel 2 are also occupied in the second RB set. As shown in Figure 5, if RB set #2 is an unavailable RB set (for example, RB set #2 is an RB set that has detected continuous LBT failures), the candidate single-slot resource is defined as occupying two consecutive RB sets, each RB set occupies one subchannel, and the indexes of these two subchannels are the same. In addition, the candidate single-slot resource cannot overlap with the unavailable RB set. Therefore, for time slot 0, (RB set #0-subchannel 0) + (RB set #1-subchannel 0) is a candidate single-slot resource, and (RB set #1-subchannel 0) + (RB set #2-subchannel 0) cannot be used as a candidate single-slot resource because it overlaps with the unavailable RB set #2. It can be seen that in the case shown in Figure 5, there are 5 candidate single-slot resources for each time slot (respectively (RB set #0-subchannel 0) + (RB set #1-subchannel 0), (RB set #0-subchannel 1) + (RB set #1-subchannel 1), (RB set #0-subchannel 2) + (RB set #2-subchannel 0). set#1-subchannel 2), (RB set#0-subchannel 3)+(RB set#1-subchannel 3), and (RB set#0-subchannel 4)+(RB set#1-subchannel 4)), the total number of candidate single-slot resources included in the 5 time slots included in the resource selection window is 25.

[0192] It should be noted that in the drawings shown in the embodiments of the present application, the sub-channel is only a schematic diagram and does not represent the actual structure of the sub-channel. The actual sub-channel can be a continuous PRB structure or an IRB structure.

[0193] In a second possible implementation, S102 may, for example, include: determining the candidate resource set based on at least one of the initial information, target time and target frequency domain, the resources in the candidate resource set belonging to the target time in the time domain, and the resources in the candidate resource set belonging to the target frequency domain in the frequency domain.

[0194] Among them, the target frequency domain satisfies at least one of the following conditions: Condition 41, the target frequency domain is the RB set occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information (that is, the upper layer of the first terminal device specifies a specific RB set as the frequency domain of the resource selection window); Condition 42, the target frequency domain is a third number of consecutive RB sets in the resource pool, and the third number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission; Condition 43, the target frequency domain is a set of all target type RB sets in the resource pool, and the target type RB set set contains a fourth number of consecutive RB sets, and the fourth number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission. The resources of the target frequency domain do not include RB sets in any of the following situations: Case 1, RB sets with continuous LBT failures in the initial information; Case 2, the fifth number of continuous RB sets, the fifth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmission; Case 3, independent RB sets, the independent RB sets do not constitute a continuous RB set with any other RB sets in the resource pool. In Case 1, the time domain restriction condition can be: all time within the resource selection window, or the time determined according to (4) in the initial information. In Case 2, the fifth number of continuous RB sets do not include unavailable RB sets and / or RB sets with continuous LBT failures in the initial information, and the fifth number of continuous RB sets do not constitute a continuous RB set with other RB sets in the resource pool. In Case 3, the number of RB sets required for actual transmission is required to be greater than 1.

[0195] Alternatively, the target frequency domain may also be all frequency domains in the resource pool or all sub-channels in the resource pool.

[0196] As an example, the upper layer of the first terminal device gives a specified RB set. It is understandable that the first terminal device takes all candidate single-slot resources of the RB set indicated in the resource pool within the time period [n+T1, n+T2] as candidate resources, and the number is recorded as Mtotal. [n+T1, n+T2] here represents the target time. As shown in Figure 5, the upper layer indicates that the RB set for PSCCH and / or PSSCH transmission is located in RB set#0 and RB set#1, and the candidate resource set is only all candidate single-slot resource sets in RB set#0 and RB set#1. Assuming that the transmission of the first terminal device needs to occupy 2 sub-channels, and the sub-channel indexes located in different RB sets need to be the same, then Mtotal is equal to 25.

[0197] As another example, the upper layer of the first terminal device indicates the number of consecutive RB sets occupied by PSCCH and / or PSSCH transmissions, the number of occupied subchannels, or the number of subchannels occupied in each RB set. It is understandable that the first terminal device uses all candidate single-slot resources within the time period [n+T1, n+T2] where the RB sets are continuous and the number of consecutive RB sets is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmissions as candidate resources. As shown in Figure 6, the resource pool contains a total of 5 RB sets, each RB set has 5 subchannels, RB set #3 is an RB set in which continuous LBT failures are detected, that is, an unavailable RB set; the transmission of PSCCH and / or PSSCH occupies 2 RB sets, and the number of occupied subchannels is 2; and the subchannel indexes occupied by different RB sets are the same. Therefore, candidate single-slot resources can only be defined in RB set #0 and RB set #1, and RB set #1 and RB set #2. There are a total of 5 candidate single-slot resources in RB set #0 and RB set #1, and a total of 5 candidate single-slot resources in RB set #1 and RB set #2. In this way, Mtotal is equal to 10. In this example, candidate single-slot resources cannot be defined in a separate RB set #4, nor can candidate single-slot resources be defined in RB set #3+RB set #4. In addition, the physical layer of the first terminal device can determine RB set #0, RB set #1, and RB set #2 as available RB sets, and report the available resource set determined after resource exclusion to the upper layer. In addition to the available resource set, the physical layer also needs to report the RB set that determines the available resource set, that is, RB set #0, RB set #1, and RB set #2.

[0198] In a third possible implementation, S102 may include, for example: based on the initial information, forming the candidate resource set from all resources in the resource selection window. In this implementation, reference may be made to the process of determining the set of all candidate single-slot resources in the resource selection process of New Radio on Vehicle to Everything Mode 2 (NR-V2X Mode 2). The process of determining the set of all candidate single-slot resources in the resource selection process of NR-V2X Mode 2 may include: S11, the candidate single-slot resource Rx,y is t within the time [n+T1,n+T2]. y Continuous L on the slot subCH sub-channels, where 0≤T1≤T proc,1 , T proc,1Indicates the transmission processing delay of the first terminal device, which can be {3, 5, 9, 17} physical time slots, corresponding to sub-carrier space (SCS) of {15, 30, 60, 120} kHz, respectively. 2min ≤T2≤remaining PDB, T 2min The minimum value of T2 configured by the high-level parameter t2min_SelectionWindow, remaining PDB is the remaining packet delay budget (i.e., remaining packet delay budget), and the total number of candidate single-slot resources in the resource selection window is Mtotal. S12, the first terminal device continuously monitors the perception window [n-T0, nT proc,0 ) slot, performs PSCCH, PSSCH decoding and PSSCH-reference signal received power (RSRP) or PSCCH-RSRP measurement, T0 is the perception window length configured by the higher layer, T proc,0 The time for the first terminal device to process the previous perception result can be {1, 1, 2, 4} slots, corresponding to SCS of {15, 30, 60, 120} kHz respectively. S13, Th(pi, pj) indicates the i-th RSRP field in sl-ThresPSSCH-RSRP-List-r16, i=pi+(pj-1)*8, pi indicates the priority indicated in the received direct link control information (Sidelink Control Information, SCI), pj indicates the priority of the first terminal device to send the transmission, pj=prio TX S14, initialize S A is the set of all candidate single-slot resources.

[0199] It can be seen that the first terminal device has determined the candidate resource set according to S102, and has made preparations for subsequent resource exclusion and resource selection. S102 may be, for example, an operation performed by the physical layer of the first terminal device.

[0200] S103: Eliminate resources from the candidate resource set to obtain an available resource set.

[0201] In specific implementation, after obtaining the candidate resource set, the first terminal device can flexibly determine the exclusion strategy to be adopted for resource exclusion based on demand. The excluded resource types may include at least one of the following: target class candidate resources, candidate resources determined according to SCI decoding information and RSRP measurement values, and candidate resources determined according to unmonitored time slots and cycles. Here, only the types of excluded candidate resources are explained, and the order of resource exclusion is not emphasized. For example, the order of resource exclusion operations may be: first exclude target class candidate resources, then exclude candidate resources determined according to unmonitored time slots and cycles, and finally exclude candidate resources determined according to SCI decoding information and RSRP measurement values; the order of resource exclusion operations may also be: first exclude candidate resources determined according to unmonitored time slots and cycles, then exclude target class candidate resources, and finally exclude candidate resources determined according to SCI decoding information and RSRP measurement values. Wherein, the target class candidate resources are located in the target RB set, which may refer to the target class candidate resources and the target RB set having an intersection (also referred to as overlap), including partial overlap or full overlap of the target class candidate resources and the target RB set.

[0202] The target RB set satisfies at least one of the following conditions: Condition 51: the target RB set is an RB set with consecutive LBT failures in the initial information; Condition 52: the target RB set is an unavailable RB set in the initial information; Condition 53: the target RB set is a sixth number of consecutive RB sets, where the sixth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmissions; Condition 54: the target RB set is an independent RB set that does not form a continuous RB set with any other RB set in the resource pool. Condition 54 requires that the number of RB sets required for actual transmission be greater than 1.

[0203] It can be understood that after the resource exclusion in S103, it is required that the ratio of the number of resources in the available resource set to the number of resources in the first resource set is greater than or equal to a first threshold (such as 20%). The available resource set can also be expressed as a remaining candidate resource set or a remaining candidate resource set that meets the requirements, and the first resource set is any of the following: the first resource set is all candidate resources in the resource selection window; the first resource set is all candidate resources in the resource selection window except the target class candidate resources; the first resource set is all candidate resources in the target frequency domain; the first resource set is all candidate resources in the target frequency domain except the target class candidate resources.

[0204] For example, the first resource set includes 10 resources, and the number of resources included in the available resource set must be greater than or equal to (20%*10)=2.

[0205] It should be noted that if, after resource exclusion, the number of resources in the available resource set (or the remaining candidate resource set) does not meet the requirements, it is necessary to increase the RSRP threshold value and then re-execute resource exclusion or re-execute partial resource exclusion.

[0206] It can be seen that the first terminal device has determined the available resource set according to S103 and has made preparations for subsequent resource selection. S103 may be, for example, an operation performed by the physical layer of the first terminal device.

[0207] As an example, after S103, it may also include: the physical layer of the first terminal device sends the available resource set and the RB set where the available resource set is located to the upper layer, so that the upper layer performs the following selection operation S104 accordingly.

[0208] Optionally, after S103, the method may further include:

[0209] S104: Select a target resource from the set of available resources, where the target resource is used by the first terminal device to perform direct link communication with the second terminal device operating in an unlicensed frequency band.

[0210] In specific implementation, after obtaining the available resource set, the first terminal device can flexibly determine the selection strategy to be adopted for resource selection based on demand. The embodiment of the present application does not limit the specific selection strategy.

[0211] Optionally, after S104, the method may further include:

[0212] S105: The first terminal device and the second terminal device perform SL-U communication based on the target resource.

[0213] In this way, in this method, after the first terminal device obtains the initial information of the other party corresponding to the Sidelink, it obtains the available resource set through the steps of determining the candidate resource set and resource exclusion. Therefore, the first terminal device can select a suitable target resource according to the available resource set and the RB set where the available resource set is located, and prepare for the first terminal device to conduct SL-U communication with the other party through the target resource.

[0214] In some implementations, considering that the sending parameters are usually determined based on CBR in the congestion control mechanism, the above-mentioned RSSI definition provided in the embodiment of the present application makes CBR more accurate. Based on this accurate CBR, more appropriate sending parameters can be matched in the congestion control mechanism, thereby improving the transmission performance of the service.

[0215] As an example, the method may further include: matching corresponding sending parameters based on the CBR; and sending the service to be sent to the second terminal device along the SL-U based on the target resources and the sending parameters.

[0216] The sending parameters may include a first parameter set and a second parameter set, the first parameter set including at least one of the following parameters: maximum transmission power, number of retransmissions, number of sub-channels occupied by resources, and modulation and coding scheme (MCS) range; the second parameter set includes a channel occupancy ratio (CR) upper limit. If the measured channel occupancy exceeds the channel occupancy ratio upper limit, the sending of the service to be sent is abandoned.

[0217] In addition, in order to further optimize the first possible implementation method in S102 above, the method may further include: obtaining a CBR, where the CBR is the ratio of the number of subchannels whose RSSI exceeds the second threshold to the number of all subchannels in the target measurement window. Optionally, parameters such as the number of subchannels occupied by PSCCH and / or PSSCH transmissions and the maximum transmission power can be determined based on the measurement results of the CBR. In this way, the reliability of transmission can be guaranteed, thereby improving the reliability of the system. The embodiments of the present application define several methods for calculating RSSI, see the description of the relevant parts below.

[0218] Among them, the frequency domain range of the target measurement window is at least one of the following: the frequency domain range of the resource pool and / or resource selection window; the RB set in the resource pool and / or resource selection window except the unavailable RB set in the initial information; the RB set in the resource pool and / or resource selection window except the RB set with continuous LBT failures in the initial information, the target frequency domain; the RB set in the target frequency domain except the unavailable RB set in the initial information; the RB set in the target frequency domain except the RB set with continuous LBT failures in the initial information.

[0219] The process of measuring CBR can also be described as: determining the ratio of the subchannel that meets the second condition within the target measurement period to all subchannels in the target measurement window as CBR, wherein the above-mentioned second condition can be: the first RSSI corresponding to the subchannel exceeds the preset threshold value.

[0220] In order to make the obtained CBR more accurate, a more reasonable RSSI calculation method is designed. Each time slot includes multiple symbols, including one or two candidate start symbols for PSCCH and / or PSCCH transmission. The RSSI is defined as at least one of the following: the linear average of all received powers on the orthogonal frequency division multiplexing (OFDM) symbols configured for PSCCH and PSSCH in a time slot, excluding the start symbol; the maximum value of at least two values ​​among the first value, the second value, and the third value. The first value is the linear average of the received powers on all symbols between the first start symbol and the second start symbol (excluding the first start symbol and the second start symbol) in the OFDM symbols configured for PSCCH and PSSCH in a time slot; the second value is the linear average of the received powers on all symbols after the second start symbol (excluding the second start symbol) in the OFDM symbols configured for PSCCH and PSSCH in a time slot; and the third value is the linear average of the received powers on all symbols in the OFDM symbols configured for PSCCH and PSSCH in a time slot, excluding the first start symbol and the second start symbol. The first starting symbol here represents the first candidate starting symbol for PSCCH and / or PSCCH transmission in a time slot, and the second starting symbol represents the second candidate starting symbol for PSCCH and / or PSCCH transmission in a time slot. As shown in Figure 7, a time slot includes 14 symbols, of which 13 symbols are symbols configured for PSCCH and PSSCH transmission (symbol 0-symbol 12), and the last symbol is used for transmit-receive conversion. Assuming that the energy measured on each symbol is P0-P13 respectively, then, in one case, RSSI is defined as: RSSI = (P1+P2+…+P5+P7+…+P12) / 11; in another case, RSSI = Max{RSSI-1, RSSI-2}, or RSSI = Max{RSSI-1, RSSI-2, RSSI-3}, or RSSI = Max{RSSI-1, RSSI-3}, where RSSI-1 = (P1+P2+…+P5+P7+…P12) / 11, RSSI-2 = (P1+P2+…+P5) / 5, RSSI-3 = (P7+P8+…+P12) / 6.

[0221] In an embodiment of the present application, a process of measuring the channel occupancy ratio (CR) may also be included. CR represents the ratio of the subchannels occupied in the measurement window and / or the subchannels authorized for occupation (expected occupation) to all subchannels in the measurement window. The frequency domain range of the measurement window for measuring CR is at least one of the following: the frequency domain range of the resource pool / resource selection window; the RB sets in the resource pool / resource selection window except the unavailable RB sets in the initial information; the RB sets in the resource pool / resource selection window except the RB sets with continuous LBT failures in the initial information, the target frequency domain; the RB sets in the target frequency domain except the unavailable RB sets in the initial information; the RB sets in the target frequency domain except the RB sets with continuous LBT failures in the initial information. For example, the resource pool includes three RB sets: RB set#0, RB set#1, and RB set#2, where RB set#0 is the RB set with detected continuous LBT failures. Then, the frequency domain range for measuring CR is only RB set#1 and RB set#2.

[0222] It can be seen that through the definition of RSSI and the method of measuring CBR provided in the embodiments of the present application, a more accurate CBR can be obtained, making it possible to determine reasonable sending parameters during the congestion control process.

[0223] It should be noted that the definition of RSSI, the measurement of CR, and the measurement of CBR may be performed before S102 or after S102.

[0224] It should be noted that the definition of RSSI, the method of measuring CR, the method of measuring CBR, and the process of determining the sending parameters provided in the embodiments of the present application can be implemented as separate embodiments or together with the method shown in Figure 2.

[0225] Thus, the SL-U resource determination mechanism provided in the embodiments of the present application can, on the one hand, reduce the complexity of the overall resource selection process and the overhead of resource indication, and can also reduce the impact of transmission failures due to channel access failures, thereby increasing transmission efficiency. Furthermore, an RSSI measurement method suitable for the special structure of the SL-U is also provided, ensuring more accurate RSSI measurement, thereby improving the accuracy of CBR measurement.

[0226] It should be noted that the above embodiments all use the first terminal device as the execution subject, and introduce how to realize the selection of SL-U resources when the first terminal device has the need to communicate with the second terminal device using SL-U. When other terminal devices have the need to communicate with other terminal devices using SL-U, they can also execute this method. Please refer to the embodiment shown in Figure 2 for details. For example, when the second terminal device has the need to communicate with the first terminal device using SL-U, the second terminal device can also serve as the execution subject of the method and select the resources used for SL-U communication with the first terminal device. Specifically, the first terminal device and the second terminal device in each step of the above method are replaced as the second terminal device to execute the specific embodiment of the method.

[0227] Accordingly, an embodiment of the present application further provides a direct link resource selection device 800 operating in an unlicensed frequency band, as shown in FIG8 . The device 800 is applied to a first terminal device, and includes:

[0228] An acquisition unit 801 is used to acquire initial information;

[0229] A determining unit 802 is configured to determine a candidate resource set based on the initial information;

[0230] The obtaining unit 803 is configured to exclude resources from the candidate resource set to obtain an available resource set.

[0231] Optionally, the selection unit 804 is configured to select a target resource from the set of available resources.

[0232] Optionally, the initial information includes at least one of the following information:

[0233] Available RB sets;

[0234] Unavailable RB set;

[0235] RB set with consecutive LBT failures;

[0236] Time information corresponding to the RB set of consecutive LBT failures;

[0237] The number of RB sets occupied by PSCCH and / or PSSCH transmission in one time unit;

[0238] The set of RBs occupied by PSCCH and / or PSSCH transmissions within a time unit;

[0239] The number of subchannels occupied by PSCCH and / or PSSCH transmissions within a time unit;

[0240] The number of subchannels occupied by PSCCH and / or PSSCH transmission in one RB set within one time unit;

[0241] The starting PRB of the resource pool.

[0242] Optionally, the available RB set satisfies at least one of the following conditions:

[0243] The available RB set is a continuous RB set in the frequency domain;

[0244] The available RB set does not include an RB set with consecutive LBT failures;

[0245] The number of RB sets in any combination of consecutive RB sets in the available RB sets is greater than or equal to the number of RB sets occupied by PSSCH and / or PSCCH transmission.

[0246] Optionally, the RB set occupied by PSCCH and / or PSSCH transmission within the one time unit satisfies at least one of the following conditions:

[0247] The RB set occupied by the PSCCH and / or PSSCH transmission within the one time unit is a continuous RB set in the frequency domain;

[0248] The RB set occupied by PSCCH and / or PSSCH transmission within the one time unit does not include the RB set with continuous LBT failures.

[0249] Optionally, the resources in the candidate resource set need to meet at least one of the following conditions:

[0250] Located in one of the time units in the time domain;

[0251] A first number of RB sets are included in the frequency domain, wherein each RB set occupies a second number of sub-channels.

[0252] Optionally, the first quantity and / or the second quantity needs to meet at least one of the following conditions:

[0253] The product of the first number and the second number is equal to the number of subchannels occupied by PSCCH / PSSCH transmission;

[0254] The second number of sub-channels are continuous sub-channels;

[0255] The indexes of the second number of sub-channels occupied by different RB sets in the first number of RB sets are the same;

[0256] The first number of RB sets are continuous RB sets;

[0257] The first number of RB sets does not include any unavailable RB set in the initial information;

[0258] The first number of RB sets does not include any RB set with consecutive LBT failures in the initial information;

[0259] The first number is equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission in one time unit in the initial information;

[0260] The first number of RB sets is the RB sets occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information.

[0261] Optionally, the determining unit 802 is specifically configured to:

[0262] Based on at least one of the initial information, the target time and the target frequency domain, the candidate resource set is determined, the resources in the candidate resource set belong to the target time in the time domain, and the resources in the candidate resource set belong to the target frequency domain in the frequency domain.

[0263] Optionally, the target frequency domain satisfies at least one of the following conditions:

[0264] The target frequency domain is an RB set occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information;

[0265] The target frequency domain is a third number of continuous RB sets in the resource pool, where the third number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission;

[0266] The target frequency domain is a set of all target type RB sets in the resource pool, and the target type RB set set includes a fourth number of consecutive RB sets, where the fourth number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission.

[0267] Optionally, the target frequency domain resources do not include an RB set in at least one of the following situations:

[0268] The RB set of consecutive LBT failures in the initial information;

[0269] A fifth number of consecutive RB sets, where the fifth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmission.

[0270] An independent RB set, where the independent RB set does not form a continuous RB set with any other RB set in the resource pool.

[0271] Optionally, the obtaining unit 803 is specifically configured to:

[0272] The target class candidate resources are excluded from the candidate resource set to obtain the available resource set, where the target class candidate resources are located in a target RB set.

[0273] Optionally, the target RB set satisfies at least one of the following conditions:

[0274] The target RB set is the RB set with consecutive LBT failures in the initial information;

[0275] The target RB set is an unavailable RB set in the initial information;

[0276] The target RB set is a sixth number of consecutive RB sets, where the sixth number is smaller than the number of RB sets occupied by PSCCH and / or PSSCH transmission;

[0277] The target RB set is an independent RB set, and the independent RB set does not form a continuous RB set with any other RB set in the resource pool.

[0278] Optionally, a ratio of the number of resources in the available resource set to the number of resources in the first resource set is greater than or equal to a first threshold, wherein the first resource set is any one of the following:

[0279] The first resource set is all candidate resources in the resource selection window;

[0280] The first resource set is all candidate resources in the resource selection window except the target class candidate resources.

[0281] Optionally, the apparatus 800 further includes:

[0282] The calculation unit is configured to obtain a CBR, where the CBR is a ratio of the number of sub-channels whose RSSI exceeds a second threshold to the number of all sub-channels in the resource selection window.

[0283] Optionally, the RSSI is defined in any one of the following ways:

[0284] The RSSI is the linear average of all received powers on the orthogonal frequency division multiplexing OFDM symbols configured for PSCCH and PSSCH in a time slot, excluding the start symbol;

[0285] The RSSI is the maximum value of at least two values ​​among the first value, the second value, and the third value, wherein the first value is the linear average value of the received power on all symbols between the first starting symbol and the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot; the second value is the linear average value of the received power on all symbols after the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot; and the third value is the linear average value of the received power on all symbols except the first starting symbol and the second starting symbol in the OFDM symbol configured for PSCCH and PSSCH in a time slot.

[0286] Optionally, the frequency domain range of the target measurement window is at least one of the following:

[0287] The frequency domain range of the resource pool;

[0288] RB sets in the resource pool except the unavailable RB set in the initial information;

[0289] RB sets in the resource pool except the RB sets with consecutive LBT failures in the initial information.

[0290] It should be noted that the specific implementation of the device 800 and the technical effects achieved can be found in the relevant description of the method shown in FIG2 .

[0291] In addition, an embodiment of the present application further provides a terminal device 900, as shown in FIG9 , wherein the terminal device 900 includes a processor 901 and a memory 902:

[0292] The memory 902 is used to store programs;

[0293] The processor 901 is configured to execute the method provided in FIG. 2 according to the program.

[0294] In addition, an embodiment of the present application further provides a storage medium, which is used to store a program. The program runs on a processor to execute the method provided by the embodiment of the present application.

[0295] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects and are not used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of this application can be implemented in an order other than those illustrated or described herein. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0296] Through the description of the above implementation methods, it can be known that those skilled in the art can clearly understand that all or part of the steps in the above-mentioned embodiment methods can be implemented by means of software plus a general hardware platform. Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a storage medium, such as a read-only memory (ROM) / random access memory (RAM), a disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network communication device such as a router) to execute the methods described in each embodiment of the present application or certain parts of the embodiments.

[0297] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system embodiments and device embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The device and system embodiments described above are merely schematic. The modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without making any creative effort.

[0298] The above description is merely an optional embodiment of the present application and is not intended to limit the scope of protection of the present application. It should be noted that, for those skilled in the art, several improvements and modifications may be made without departing from the scope of protection of the present application, and such improvements and modifications shall also be considered within the scope of protection of the present application.

Claims

1. A method for determining a direct link resource operating in an unlicensed frequency band, applied to a first terminal device, the method comprising: Get initial information; Based on the initial information, determining a set of candidate resources; The candidate resource set is excluded to obtain an available resource set.

2. The method according to claim 1, wherein: The initial information includes at least one of the following information: Available resource block set RB set; Unavailable RB set; RB set with consecutive listen-before-speak LBT failures; Time information corresponding to the RB set of consecutive LBT failures; The number of RB sets occupied by the transmission of the physical direct link control channel PSCCH and / or the physical direct link shared channel PSSCH in one time unit; The RB set occupied by PSCCH and / or PSSCH transmission within a time unit; The number of subchannels occupied by PSCCH and / or PSSCH transmissions in one time unit; The number of subchannels occupied by PSCCH and / or PSSCH transmission in one RB set in one time unit; The starting physical resource block PRB of the resource pool.

3. The method according to claim 2, wherein: The available RB set satisfies at least one of the following conditions: The available RB set is a continuous RB set in the frequency domain; The available RB set does not include a RB set with continuous LBT failures; The number of RB sets in any continuous RB set combination among the available RB sets is greater than or equal to the number of RB sets occupied by PSSCH and / or PSCCH transmission.

4. The method according to claim 2, wherein: The RB set occupied by PSCCH and / or PSSCH transmission in the one time unit satisfies at least one of the following conditions: The RB set occupied by the PSCCH and / or PSSCH transmission within the one time unit is a continuous RB set in the frequency domain; The RB set occupied by PSCCH and / or PSSCH transmission within the one time unit does not include the RB set with continuous LBT failures.

5. The method according to any one of claims 1 to 4, wherein: The resources in the candidate resource set need to meet at least one of the following conditions: In the time domain, it is located in a time unit; In the frequency domain, the first number of RB sets is located, wherein a second number of subchannels is occupied in each RB set.

6. The method according to claim 5, wherein: The first quantity and / or the second quantity needs to satisfy at least one of the following conditions: The product of the first number and the second number is equal to the number of subchannels occupied by PSCCH and / or PSSCH transmission; The second number of sub-channels are continuous sub-channels; Indexes of the second number of sub-channels occupied by different RB sets in the first number of RB sets are the same; The first number of RB sets are continuous RB sets; The first number of RB sets does not include any unavailable RB set in the initial information; The first number of RB sets does not include any RB set with consecutive LBT failures in the initial information; The first number is equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission in a time unit in the initial information; The first number of RB sets are RB sets occupied by PSCCH and / or PSSCH transmission within a time unit in the initial information.

7. The method according to any one of claims 1 to 4, wherein: The step of determining a candidate resource set based on the initial information includes: Based on at least one of the initial information, the target time and the target frequency domain, the candidate resource set is determined, the resources in the candidate resource set belong to the target time in the time domain, and the resources in the candidate resource set belong to the target frequency domain in the frequency domain.

8. The method according to claim 7, wherein: The target frequency domain satisfies at least one of the following conditions: The target frequency domain is PSCCH and / or PSSCH in a time unit in the initial information RB set occupied by transmission; The target frequency domain is a third number of continuous RB sets in the resource pool, where the third number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission; The target frequency domain is a set of all target type RB sets in the resource pool, and the target type RB set set includes a fourth number of continuous RB sets, and the fourth number is greater than or equal to the number of RB sets occupied by PSCCH and / or PSSCH transmission.

9. The method according to claim 7 or 8, wherein: The target frequency domain resources do not include an RB set in at least one of the following situations: The RB set of consecutive LBT failures in the initial information; a fifth number of consecutive RB sets, wherein the fifth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmission; An independent RB set, where the independent RB set does not constitute a continuous RB set with any other RB set in the resource pool.

10. The method according to any one of claims 1 to 4, wherein: The step of excluding resources from the candidate resource set to obtain an available resource set includes: The target class candidate resources are excluded from the candidate resource set to obtain the available resource set, and the target class candidate resources are located in the target RB set.

11. The method according to claim 10, wherein: The target RB set satisfies at least one of the following conditions: The target RB set is the RB set with consecutive LBT failures in the initial information; The target RB set is an unavailable RB set in the initial information; The target RB set is a sixth number of consecutive RB sets, where the sixth number is less than the number of RB sets occupied by PSCCH and / or PSSCH transmission; The target RB set is an independent RB set, and the independent RB set does not constitute a continuous RB set with any other RB set in the resource pool.

12. The method according to any one of claims 1 to 11, wherein: The ratio of the number of resources in the available resource set to the number of resources in the first resource set is greater than or equal to a first threshold, wherein the first resource set is any one of the following: The first resource set is all candidate resources in the resource selection window; The first resource set is all candidate resources in the resource selection window except the target class candidate resources.

13. The method according to any one of claims 1 to 12, wherein: The method further comprises: A channel busy rate CBR is obtained, where the CBR is the ratio of the number of sub-channels whose received signal strength indication RSSI exceeds the second threshold to the number of all sub-channels in the target measurement window.

14. The method according to claim 13, wherein: The RSSI is defined in any of the following ways: The RSSI is the linear average of all received powers on orthogonal frequency division multiplexing OFDM symbols except the start symbol configured for PSCCH and PSSCH in a time slot; The RSSI is the maximum value of at least two values ​​among a first value, a second value, and a third value, wherein the first value is the linear average value of the received power on all symbols between the first starting symbol and the second starting symbol in the OFDM symbols configured for PSCCH and PSSCH in a time slot, and the second value is the linear average value of the received power on all symbols after the second starting symbol in the OFDM symbols configured for PSCCH and PSSCH in a time slot; the third value is the linear average value of the received power on all symbols except the first starting symbol and the second starting symbol in the OFDM symbols configured for PSCCH and PSSCH in a time slot.

15. The method according to claim 13 or 14, wherein: The frequency domain range of the target measurement window is at least one of the following: The frequency domain scope of the resource pool; RB sets in the resource pool except the unavailable RB set in the initial information; RB sets in the resource pool except the RB sets with consecutive LBT failures in the initial information.

16. A device for determining direct link resources operating in an unlicensed frequency band, applied to a first terminal device, the device comprising: An acquisition unit, used for acquiring initial information; A determination unit, configured to determine a candidate resource set based on the initial information; The obtaining unit is used to exclude resources from the candidate resource set to obtain an available resource set.

17. A terminal device, comprising a processor and a memory: The memory is used to store programs; The processor is configured to execute the method according to any one of claims 1 to 15 according to the program.

18. A storage medium, wherein the storage medium is used to store a program, wherein the program runs on a processor and is used to execute the method according to any one of claims 1 to 15.

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