RU2789391C1 - Method and device for selecting resources in the network system of vehicles, terminal and carrier - Google Patents

Abstract

FIELD: transport network.

SUBSTANCE: the invention relates to the selection of resources in the network system of the vehicle. The following steps are provided: if there is a service to be transferred at time n, the selection of the resource of the initial transfer of the service in the resource selection window, while the resource of the initial transfer is located between time n and time n+p; in this case, the resource selection window is a window from time n+T₁₁ to time n+T₁₂, the first time period from time n to time T11 is greater than or equal to the processing delay of the transmitting terminal, the second time period from time n to time T₁₂ is equal to or less than the required service delay range, and the value p is less than the set value of W.

EFFECT: reducing the service transmission delay.

15 cl, 19 dwg, 1 tbl

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[0001] The present application relates to the field of wireless communication and, in particular, to a method and apparatus for selecting resources in a vehicle system connected to everything, a terminal and a carrier.

BACKGROUND OF THE INVENTION

[0002] To implement direct communication between terminals in a vehicle with a system connected to everything (V2X), a direct connection mode (SideLink, SL) is introduced.

[0003] In the SL transmission mode, the terminal needs to select resources in a resource pool. The terminal determines a resource selection window and a resource listening window, and excludes resources from the resource selection window based on the listening result of the resource listening window to obtain candidate resources for a service to be transmitted. The terminal randomly selects resources from the candidate resources to perform a service handover to another terminal to receive the service, the handover including initial transmission and retransmission of the service.

[0004] When selecting an initial transmission resource for a service in the above manner, the terminal randomly selects a resource from the entire resource selection window, so the selected initial transmission resource may be a candidate resource located at a relatively backward position in the time domain, resulting in a large transmission delay. services.

SUMMARY OF THE INVENTION

[0005] Embodiments of the present application provide a method and apparatus for selecting resources in a vehicle system connected to everything, a terminal, and a carrier that can be used to solve the problem of high service transmission delay that occurs due to the terminal randomly selecting the resource from the entire resource selection window, and then the selected initial transmission resource may be a candidate resource located at a relative back position in the time domain. Technical solutions are described below.

[0006] In accordance with one aspect of the present application, there is provided a method for selecting resources in a system of a vehicle connected to everything, including:

[0007] if there is a service to be transmitted at time n, selecting an initial transmission resource for the service from a resource selection window, wherein the initial transmission resource is located between time n and time n+p; And

[0008] while the resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, the second time period from time n to time n+T ₁₂ is less than or equal to the required service delay range, and the value of p is less than the predetermined value W.

[0009] In accordance with one aspect of the present application, there is provided a method for selecting resources in a system of a vehicle connected to everything, including:

[0010] when there is a service to be transmitted at time n, selecting a retransmission resource for the service from a resource selection window, wherein the retransmission resource is located after the initial transmission resource for the service; And

[0011] while the resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, the second time period from time n to time n+T ₁₂ is less than or equal to the required service delay range.

[0012] In accordance with one aspect of the present application, a device is provided for selecting resources in a vehicle system connected to everything, the device including a determination module;

[0013] wherein the determination module is configured, if there is a service to be transmitted at time n, to select an initial transmission resource for the service from a resource selection window, wherein the initial transmission resource is located between time n and time n+p; And

[0014] while the resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, the second time period from time n to time n+T ₁₂ is less than or equal to the required service delay range, and the value of p is less than the predetermined value W.

[0015] In accordance with one aspect of the present application, there is provided a device for selecting resources in a vehicle system connected to everything, the device including a determination module;

[0016] The determination module is configured, if there is a service to be transmitted at time n, to select a retransmission transmission resource for the service from a resource selection window, the retransmission transmission resource being located after the initial transmission resource for the service; And

[0017] while the resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first period of time from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, and the second period time period from time n to time n+T ₁₂ is less than or equal to the required service delay range.

[0018] According to one aspect of the present application, a terminal is provided, the terminal includes a processor; a transceiver connected to the processor; and a memory configured to store executable instructions of the processor; wherein the processor is configured to download and execute executable instructions for implementing a method for selecting resources in a system of a vehicle connected to everything, in accordance with any of the aspects of execution.

[0019] According to one aspect of the present application, a computer-readable storage medium is provided, wherein executable instructions are stored on the readable storage medium, and executable instructions are loaded and executed by a processor to implement a resource selection method in a vehicle system connected to any of the following: aspects.

[0020] The technical solutions provided by the embodiments of the present application include at least the following beneficial effects.

[0021] When the terminal selects a resource from a resource selection window by selecting an initial transmission resource for a service between time n and time n+p, initial transmission of the service by a resource located at a relatively trailing position in the time domain in the resource selection window is eliminated, and delay service transmission is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings to be used in the description of the embodiments will be briefly presented below. Obviously, the drawings in the following description are only for some embodiments of the present application, and for those skilled in the art, other drawings can also be taken from these drawings without creative labor.

[0023] FIG. 1 is a schematic representation of the direct connection communication mode in the corresponding technology of the present application.

[0024] FIG. 2 is a schematic representation of resource selection in LTE-V2X in the corresponding technology of the present application.

[0025] FIG. 3 is a block diagram of the NR-V2X physical layer in the corresponding technology of the present application.

[0026] FIG. 4 is a schematic diagram of TB transmission in the corresponding technology of the present application.

[0027] FIG. 5 is a schematic diagram of the selection of resources in the system of a vehicle connected to everything in the corresponding technology of the present application.

[0028] FIG. 6 is a schematic diagram of resource selection in a vehicle system connected to everything in the corresponding technology of the present application.

[0029] FIG. 7 is a schematic diagram of resource selection in a vehicle system connected to everything in the corresponding technology of the present application.

[0030] FIG. 8 is a schematic diagram of resource selection in a vehicle system connected to everything in the corresponding technology of the present application.

[0031] FIG. 9 is a block diagram of a communication system supporting direct communication connection provided by an exemplary embodiment of the present application.

[0032] FIG. 10 is a flow diagram of a method for selecting resources in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0033] FIG. 11 is a flowchart for determining a first reselection resource from a first reselection window provided by an exemplary embodiment of the present application.

[0034] FIG. 12 is a schematic diagram of resource selection in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0035] FIG. 13 is a flowchart of a method for selecting resources in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0036] FIG. 14 is a schematic diagram of resource selection in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0037] FIG. 15 is a flowchart for determining a second reselection resource for a retransmission resource from a second reselection window provided by an exemplary embodiment of the present application.

[0038] FIG. 16 is a schematic diagram of resource selection in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0039] Fig. 17 is a block diagram of an apparatus for selecting resources in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0040] FIG. 18 is a block diagram of a device for selecting resources in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application.

[0041] FIG. 19 is a block diagram of a terminal provided by an exemplary embodiment of the present application.

DETAILED DESCRIPTION OF EMBODIMENTS

[0042] In order to make the objectives, technical solutions and advantages of the present application more clear, embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0043] First, the terms used in the embodiments of the present application will be briefly introduced.

[0044] Vehicle Connected to Everything (V2X): A key technology of the future intelligent transportation system, mainly exploring a vehicle data transmission solution based on 3GPP communication protocol. V2X communication includes vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-people (V2P) communications. V2X applications can improve driving safety, reduce congestion and vehicle energy consumption, and improve traffic efficiency.

[0045] SideLink (SL) transmission: a communication method between devices with relatively high spectrum efficiency and relatively low transmission delay. Two direct connection modes are defined in 3GPP: Mode A and Mode B. As shown in (a) of FIG. 1, in Mode A, transmission resources of the terminal are allocated by the base station on the downlink, and the terminal sends data via a direct connection based on the resources allocated by the base station; and the base station may allocate a resource for a single transmission to the terminal or may allocate a resource for a semi-static transmission to the terminal. As shown in (b) in FIG. 1, in Mode B, the terminal itself selects one resource from the resource pool for data transmission. Specifically, the terminal may select a transmission resource from a resource pool by listening, or may select a transmission resource from a resource pool by random selection.

[0046] In Mode B, among the direct connection modes, the terminal may select a transmission resource from a resource pool by listening. Next, resource selection methods in LTE-V2X and NR-V2X will be described.

[0047] 1) Resource selection method in LTE-V2X

[0048] When a new data packet arrives at time n, resource selection is required, and the terminal may select a resource within [n+T1, n+T2] ms based on the listening result in the last second, with T1<=4, 20 <=T2<=100, T1 should be chosen to be greater than the processing delay of the terminal, and T2 should be chosen to be within the required service delay range. For example, if the required service delay range is 50 ms, then 20<=T2<=50, and if the required service delay range is 100 ms, then 20<=T2<=100.

[0049] For example, as shown in FIG. 2, a new data packet arrives at time n, resource selection is required, and the resource's listening window is [n-1000, n]. The required service delay is 100ms and the resource selection window is [n+4, n+100].

[0050] The resource selection process of the terminal in the resource selection window is shown below (the detailed resource selection process may refer to steps in 3GPP TS36.213, and several basic resource selection steps are listed here).

[0051] The terminal receives all of the available resources in the resource selection window as set A, and the terminal performs a exclude operation on the resources in set A.

[0052] In step 1, if the terminal sends data about some subframes in the resource listening window without listening, then the resources in the subframes in the resource selection window that correspond to the above-mentioned some subframes are excluded.

[0053] In step 2, if the terminal has detected (found) a physical sidelink control channel (PSCCH, physical sidelink control channel) within the resource listening window, then it measures the reference signal received power (RSRP) of the physical sidelink common channel (PSSCH, physical sidelink shared channel) organized by the PSCCH, and if the measured PSSCH-RSRP is higher than the PSSCH-RSRP threshold, and it is determined that the transmission resource reserved by the PSCCH is located within the resource selection window of the terminal based on the reservation information in the control information transmitted on the PSCCH, then the terminal excludes the resource from set A. The selection of the PSSCH-RSRP threshold is determined by the priority information carried in the detected PSCCH and the priority of the data to be transmitted by the terminal.

[0054] In step 3, if the amount of remaining resources in set A is less than 20% of the total resources, then the terminal raises the PSSCH-RSRP threshold by 3 dB and repeats steps 1 to 2 until the amount of remaining resources in set A is more than 20% of the total resources.

[0055] In step 4, the terminal performs direct connection received signal strength indicator (S-RSSI) detection for the remaining resources in set A, sorts the remaining resources in set A based on the energy level, and places 20% (relative to the number of resources of set A) of the resources with the least energy into the set B.

[0056] In step 5, the terminal selects one resource from set B with equal probability to transmit data.

[0057] 2) NR-V2X resource selection method by listening

[0058] In NR-V2X, it is necessary to support automatic driving, so there are relatively high requirements for data communication between vehicles, such as relatively high throughput, relatively low latency, relatively high reliability, relatively large coverage, and relatively flexible resource allocation, etc. D.

[0059] The NR-V2X physical layer structure is shown in FIG. 3, PSCCH301 for transmission of control information is included in PSSCH302 for data transmission, which also means that PSCCH301 and PSSCH302 must be sent at the same time.

[0060] The current standard only supports that the initial transmission of the current transport block (TB) reserves the retransmission of the current TB, the retransmission of the current TB reserves the retransmission of the current TB, and the initial transmission or retransmission of the previous TB reserves the initial transmission of the current TB.

[0061] As shown in FIG. 4, the current TB is TB2 and the previous TB is TB1. Initial transmission 421 TB2 reserves retransmission 422 and retransmission 423 TB2, retransmission 422 TB2 reserves retransmission 423 TB2, initial transmission 411 TB1 reserves initial transmission 421 TB2, retransmission 412 TB1 reserves retransmission 422 TB2, and retransmission 413 TB1 reserves retransmission 423 TB2.

[0062] In NR-V2X, in the aforementioned mode B, the terminal must also select the resource itself. Its resource selection mechanism is similar to the resource selection mechanism in LTE-V2X mentioned above.

[0063] The terminal generates a service data packet at time n and needs to perform resource selection, and receives all resources in the resource selection window as set A. The resource selection window starts at n+T1 and ends at n+T2. T1>= terminal preparation time for data sending and resource selection, T2min<=T2<= required service delay range. The value of T2min is {1, 5, 10, 20}*2 ^µ slots, where µ=0,1,2,3 corresponds to the case where the subcarrier spacing is 15, 30, 60, 120 kHz.

[0064] As shown in FIG. 5, the terminal performs resource listening from time n-T0 to time n, and the range of T0 is [100, 1100] ms. If the terminal hears the PSCCH, then it measures the RSRP of the PSCCH or the RSRP of the PSSCH of the scheduled PSCCH, and if the measured RSRP is greater than the RSRP threshold, and it is determined that the resource reserved by the PSCCH is within the resource selection window based on the resource reservation information in the control information carried on the PSCCH, then the resource is excluded from set A.

[0065] After resource deletion, the terminal randomly selects several resources from set A as its send resources for initial transmission and retransmission. The above RSRP threshold is determined by the priority carried on the PSCCH that the terminal is listening to and the priority of the data to be sent by the terminal. In addition, the difference between the time domain position of the initial transmission resource selected by the terminal and the time domain position of the last retransmission resource must be less than or equal to W. In NR-V2X, W is 32 slots. The length of each slot is related to the sub-carrier spacing, and if the sub-carrier spacing is 15 kHz, then the slot length is 1 millisecond (ms), and if the sub-carrier spacing is 30 kHz, then the slot length is 0.5 ms.

[0066] It should be noted that resource preemption is supported in NR-V2X, i.e., after the terminal preempts resources, set A may include the resource block reserved by the low priority terminal, and the terminal preempts the resource block reserved by the low priority terminal. For example, resource crowding can be achieved by adjusting the RSRP threshold.

[0067] Assume that in FIG. 5, terminal 1 generates data and selects a resource at time n, and terminal 1 determines a resource selection window from n+T1 to n+T2 and a resource listening window from n-T0 to n. In the resource listening window, terminal 1 hears that terminal 2 sends PSCCH and PSSCH at time n-a and reserves resource x at time n+b. After listening to the PSCCH sent by terminal 2, terminal 1 learns that the priority carried on the PSCCH of terminal 2 is lower than the priority of the data to be sent, so it raises the RSRP threshold so that the probability that the measured RSRP on which terminal 2 sends a signal, below the RSRP threshold, increases, and when the measured RSRP is below the RSRP threshold, terminal 1 does not exclude resource x reserved by terminal 2. If terminal 1 randomly selects resource x reserved by terminal 2 in set A, in which resources have been excluded, then terminal 1 preempts resource x. Conversely, if terminal 1 detects that the priority carried on the PSCCH of terminal 2 is higher than the priority of the data to be sent, it lowers the RSRP threshold so that the resource reserved by terminal 2 is easier to discard, thereby avoiding the use of one and the same resource block along with the high priority terminal.

[0068] In addition, NR-V2X supports re-evaluation after initial selection of resources.

[0069] As shown in FIG. 6, the terminal generates data at time n and determines a resource listening window and a resource selection window for resource selection, and the terminal selects an initial transmission resource x at time time n+a and retransmission resources y and z at time n+b and at time n+c. After time n has elapsed, the terminal still reassesses the PSCCH. Up to time n+a,if the terminal learns that resource x, resource y, or resource z is reserved by another terminal through reassessment (i.e., a contention occurs in the resource) and the measured RSRP is higher than the RSRP threshold, then the terminal may release the corresponding resource and may reselect another resource provided that the required service delay is met. After a moment of timen+a, since the terminal sent the PSCCH and PSSCH to resource x and reserved resource y and resource z, the terminal may release resource y or resource z and reselect resources only if the terminal detects that the high priority UE is preempting resource y or resource z by reselecting assessment and RSRP exceeds the RSRP threshold.

[0070] When retransmitting a resource, there is a blind retransmission mode and a hybrid automatic repeat quest (HARQ) retransmission mode.

[0071] 1) Blind retransmission: the terminal simultaneously selects a plurality of time-frequency resources and sends the same data each time, and the terminal for receiving the service does not feedback for each transmission of the terminal, but only combines the received data.

[0072] 2) HARQ retransmission: the terminal simultaneously selects a plurality of time-frequency resources and sends the same data each time. For each transmission, the terminal for receiving the service returns ACK/NACK to the terminal depending on whether the reception was successful or not, with ACK representing a successful reception and NACK representing a failed reception. In NR V2X, after a terminal receives an ACK, it stops sending data and releases time-frequency resources that were not being used. The receiving side performs the HARQ feedback to the transmitting side via a Physical Direct Connection Feedback Channel (PSFCH).

[0073] PSFCH resources are configured for each resource pool. There are three configurations in NR-V2X i.e. N=1, N=2 and N=4. As shown in FIG. 7, N=1 means that every slot in the resource pool is configured with a PSFCH resource, N=2 means that every two slots are configured with a PSFCH resource, and N=4 means that every four slots are configured with a PSFCH resource.

[0074] When terminal 1 sends data to terminal 2 in slot t, then the HARQ feedback from terminal 2 to terminal 1 for this data transmission occurs in slot t+ a, where a is greater than or equal to K, slot t+ a includes the resource PSFCH and k occupies 2 or 3 slots in NR-V2X.

[0075] Referring to FIG. 7, assuming N=4 (i.e. every four slots configured with a PSFCH resource) and k=2 if terminal 1 sends data to terminal 2 in slot 1, then t+a corresponds to slot 4, and terminal 2 performs HARQ feedback to terminal 1 in slot 4. If terminal 1 sends data to terminal 2 in slot 3, then t+acorresponds to slot 8, and terminal 2 performs HARQ feedback for terminal 1 in slot 8.

[0076] The current NR V2X standard does not explicitly state whether to support a receiving terminal to perform 1-bit HARQ feedback for the same PSFCH resource for multiple transmissions of the current TB by the transmitting terminal when HARQ retransmission is enabled.

[0077] When a terminal for receiving a service is supported to perform 1-bit HARQ feedback for the same PSFCH resource for multiple transmissions of the current TB by the terminal (denoted as case 1), as shown in subplot 1 in FIG. 8, assuming N=4 (i.e., every four slots are configured with a PSFCH resource) and k=2, after the terminal sends the initial transmission to the receiving terminal in slot 1, it can retransmit to slot 2, and the terminal for receiving the service may perform HARQ feedback for initial transmission and retransmission by the terminal in slot 4.

[0078] When a terminal for receiving a service is supported to perform 1-bit HARQ feedback for one PSFCH resource for one current TB transmission by the terminal (denoted as case 2), as shown in subplot 2 in FIG. 8, assuming N=4 and k=2, after the terminal sends an initial transmission to the terminal to receive the service in slot 1, the terminal that needs to receive the service performs HARQ feedback for this initial transmission in slot 4, and then the terminal performs retransmission in slot 6. Thereafter, the terminal performs HARQ feedback for the terminal to retransmit in slot 8 to receive the service.

[0079] From the above analysis, it can be deduced that in case 1 for multiple transmissions of one TB, there is no required time interval between two adjacent transmissions. In case 2, for multiple transmissions of one TB, at least one PSFCH resource must be included between two adjacent transmissions. Therefore, in relation to the above two cases, it is necessary to develop resource selection algorithms, respectively.

[0080] FIG. 9 is a block diagram of a communication system supporting a direct communication connection provided by an exemplary embodiment of the present application. The communication system can be a schematic diagram of the 5G system architecture without roaming, and the system architecture can be applied to the Vehicle Connected to Everything (V2X) service using D2D technology.

[0081] The system architecture includes a data network (DN, data network), in which the V2X application server necessary for the V2X service is provided. The system architecture also includes a 5G core network, and the network functions of the 5G core network include: unified data management (UDM, unified data management), policy control function (PCF, policy control function), network reconfiguration function (NEF, network exposure function), application function (AF, application function), unified data repository (UDR, unified data repository), access and mobility management function (AMF), session management function (SMF), and user plane function (UPF).

[0082] The system architecture also includes a new generation-radio access network (NG-RAN) and four user equipments (i.e., user devices 1 to 4) shown as an example, with each the user equipment is provided with the V2X application. The NG-RAN is provided with one or more network access devices such as a base station (gNB). The user equipment performs an uplink transmission to the access network equipment.

[0083] In the system architecture, the data network is connected to the UPF of the 5G core network through the N6 reference point, and the V2X application server is connected to the V2X application in the user equipment through the V1 reference point; The NG-RAN connects to the AMF and UPF of the 5G core network, and the NG-RAN connects to the user equipment 1 and user equipment 5 through the reference point Uu, respectively; and a direct connection between a plurality of user devices is performed via the PC5 reference point, and a plurality of V2X applications are connected via the V5 reference point. The above reference points may also be referred to as "interfaces".

[0084] FIG. 10 shows a flowchart of a method for selecting resources in a system of a vehicle connected to everything provided by an exemplary embodiment of the present application. The method may be performed by user equipment in V2X as shown in FIG. 9, the user equipment serves as a terminal for sending a service when executing the method, and the method includes the following steps.

[0085] In step 1001, if there is a service to be transmitted at time n, an initial transmission resource for the service is selected from a resource selection window, with the initial transmission resource located between time n and time n+p.

[0086] The resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, the second time period from time time n to time n+T ₁₂ is less than or equal to the required service delay range, and the value p is less than the predetermined value W.

[0087] Optionally, if there are multiple resources for service transmission in the resource selection window, then the terminal performs resource selection only when the resource selection condition is satisfied.

[0088] In a V2X system, two terminals communicate with each other via a direct connection. In particular, the two terminals receive direct connection mode B, i.e., the terminal itself selects a resource from a resource pool for data transmission. If there is a service to be transmitted by the terminal at time n, then the terminal may perform resource selection in the resource selection window from time n+T ₁₁ to time n+T ₁₂ to select an initial transmission resource that is a time-frequency resource between time n and time n+p. The terminal uses the initial transmission resource to transmit the service to another terminal for the first time.

[0089] Optionally, if there is a service to be transmitted by the terminal at time n and there is no initial transmission resource that satisfies the resource selection condition, then the terminal raises the RSRP threshold (e.g., 3 dB) until a resource is available, which would meet the resource selection condition to ensure that the service is transmitted to the receiving terminal within the required delay range of the service.

[0090] Optionally, the preset value W is not less than the difference between the time domain position of the initial transmission resource and the time domain position of the last retransmission resource selected by the terminal.

[0091] Optionally, the above set value W is 32 slots. The length of each slot is related to the subcarrier spacing as shown in Table 1.

[0092] Table 1: Mapping relationship between slot length and subcarrier spacing

Subcarrier spacing (kHz) Slot length (ms) 15 1 thirty 0.5 60 0.25 120 0.125 240 0.0625

[0093] As shown in Table 1, if the subcarrier spacing is 15 kHz, then the slot length is 1 ms, and the set value of W is 32 ms; and if the sub-carrier spacing is 30 kHz, then the slot length is 0.5 ms and the set W value is 16 ms.

[0094] In one example, selecting an initial transmission resource for a service from a resource selection window includes: determining a resource listening window and a resource selection window; excluding resources from the resource selection window to obtain candidate resources in the resource selection window based on a listening result of the resource listening window; and selecting an initial transmission resource for the service from the candidate resources.

[0095] Optionally, the resource listening window is a window from time nT ₀ to time n. The value of T ₀ is [100,1100] ms.

[0096] Optionally, the initial transmission resource selection for the service from the candidate resources may be: determining an initial transmission resource for the service with equal probability from the candidate resources.

[0097] Optionally, the time-frequency positions of candidate resources may partially overlap.

[0098] For example, after excluding resources from the resource selection window, the terminal obtains four candidate resources in the resource selection window: resource 1, resource 2, resource 3, and resource 4. The terminal selects an initial transmission resource for a service with equal probability from the four resources. The probability of selecting resource 1, resource 2, resource 3 and resource 4 respectively as the initial transmission resource is 0.25.

[0099] Optionally, the terminal takes all available resources in the resource selection window as set A, and excludes resources from the resource selection window based on the result of listening to the resource listening window, i. performs an exception for the resources in set A, which includes at least one of the following steps.

[00100] In step 1, if the terminal sends data in some slots within the resource listening window without listening, then the resources in the corresponding slots within the resource selection window are excluded.

[00101] In step 2, if the terminal has detected a PSCCH within the resource listening window, then it measures the scheduled PSCCH RSRP or PSCCH RSRP, and if the measured PSSCH-RSRP is higher than the RSRP threshold, and it is determined that the transmission resource, reserved by the PSCCH is located within the resource selection window of the terminal based on the reservation information in the control information carried on the PSCCH, then the terminal excludes the resource from set A. The selection of the RSRP threshold is determined by the priority information carried in the detected PSCCH and the overhead priority data to be transmitted by the terminal.

[00102] In step 3, if the amount of remaining resources in set A is less than 20% of the total resources, then the terminal raises the RSRP threshold by 3 dB and repeats steps 1 to 2 until the amount of remaining resources in set A is more than 20% of the total resources.

[00103] Optionally, the resources in set A after the above steps are the remaining resources after the resources are excluded from the resource selection window, i.e. resource candidates.

[00104] Optionally, after obtaining candidate resources by resource elimination, when the terminal selects a resource from the candidate resources, resource preemption is supported for the resource reserved by the low priority terminal.

[00105] For example, the process of evicting resources is described above in the embodiment corresponding to FIG. 5.

[00106] In one example, the terminal re-evaluates (continuously listens to) the initial transmission resource; and when a contention occurs in the initial transmission resource, the terminal determines the first reselection resource for the initial transmission resource from the first reselection window.

[00107] The first reselection window is a window from time n+t ₁ +T ₂₁ to time n+t ₁ +T ₂₁ , the first reselection resource is a time frequency resource in the candidate resources of the first reselection window, which has a distance from the initial transmission resource less than or equal to the distance i , wherein i is an integer greater than or equal to 0, the time n+t ₁ is the point at which it is determined that a collision occurs in the initial transmission resource, and the candidate resources are is the set of resources in the first reselection window that were not excluded after exclusion based on the result of the resource's listening window listening.

[00108] It should be noted that if there is more than one time-frequency resource in the candidate resources of the first reselection window, the distance from which to the initial transmission resource is less than or equal to the distance i , the terminal selects one time-frequency resource as the first reselection resource from them with equal probability.

[00109] Optionally, the initial transmission resource is located at time n+b, which is located between time n and time n+p, and the terminal's reassessment of the initial transmission resource means that the terminal listens for resources in each slot for a period of time from time time n to time n+b to determine whether the other terminal also reserves the initial transmission resource or not.

[00110] Optionally, the first time period from time n+t ₁ to time n+t ₁ +T ₂₁ is greater than or equal to the terminal processing delay, and the second time period from time t ₁ to time n+t ₁ +T ₂₂ less than or equal to the required service delay range.

[00111] For example, t ₁ is 100 ms, and the terminal determines that a collision occurs in the initial transmission resource at n+100 ms; the terminal processing delay is 10 ms, and the first time period from time n+t ₁ to time n+t ₁ +T ₂₁ is equal to the terminal processing delay, which is also 10 ms; and the required service delay range is 1000 ms, the second time period from time n to time n+t ₁ +T ₂₂ is equal to the required service delay range, and T ₂₂ is 900 ms. The first reselection window is a window from time n+t ₁ +10 to time n+t ₁ +900.

[00112] Collision occurring in the initial transmission resource means that during reassessment, the initial transmission resource selected by the terminal is also reserved by another terminal as an initial transmission resource or a retransmission resource for transmitting another service.

[00113] Optionally, when a contention occurs in the initial transmission resource of UE1, the UE1 measures the RSRP of the other UE2 in conflict, and only when the measured RSRP of UE2 is higher than the RSRP threshold of UE1, the UE1 reselects the resource and determines the first resource of the retry. choice. The aforementioned RSRP threshold is determined by the priority carried in the PSCCH listened by UE1 and the priority of the overhead to be transmitted.

[00114] After determining that a contention occurs in the initial transmission resource, the terminal releases the initial transmission resource, determines a window from time n+t ₁ +T ₂₁ to time n+t ₁ +T ₂₂ as the first reselection window, and excludes resources from the first reselection window for receiving candidate resources based on the listening result of the first resource listening window, the exclusion process being described above. The first resource listening window is the window from time n+t ₁ -T ₀ to time n+t ₁ .

[00115] Referring to FIG. 11, determining the first reselection resource from the candidate resources in the first reselection window may include the following steps.

[00116] In step 1101, the first slot interval s ₁ -i to s ₁ +i is determined, where s ₁ is the slot corresponding to the initial transmission resource, and the initial value of i is R ₁ , where R ₁ is an integer not less than 0.

[00117] In step 1102, when a candidate resource located in the first slot interval is present in the first reselection window, the first reselection resource is determined with equal probability from the candidate resources located in the first slot interval.

[00118] In step 1103, when there is no candidate resource located in the first slot interval in the first reselection window, determination of the first slot interval s ₁ -i to s ₁ +i is performed again after i is added by one.

[00119] For example, with reference to FIG. 12, candidate resources include resource x, resource y, and resource z. The slot corresponding to initial transmission resource a is slot 5, the initial value of i is 1, the first slot interval is slot 4 to slot 6, and there is no candidate resource in the first reselection window. When i is added to one ( i.e., i + 1), the terminal determines that the first slot interval is the interval from slot 3 to slot 7. At this time, two candidate resources are present in the first slot interval: resource x and resource y , and the terminal randomly selects one of the two candidate resources with equal probability as the first reselection resource.

[00120] Optionally, the first reselection resource and the resource that was selected are located at different times, and the resource that was selected is the resource selected by the terminal for another transmission of the current TB.

[00121] Optionally, the current TB is a transport block corresponding to the service to be transmitted that is present at time n. The current TB may include a plurality of transmissions, including an initial transmission and at least one retransmission.

[00122] If resource m is a retransmission resource selected by the terminal to retransmit the current TB, then the terminal does not take resource m as the first reselection resource when performing initial transmission resource reselection.

[00123] Thus, in the method of the present embodiment, when the terminal selects a resource from the resource selection window by selecting an initial transmission resource for a service between time n and time n+p, the initial transmission of the service by the candidate resource located at relatively the back position in the time domain in the resource selection window is avoided, and the transmission delay of the service is reduced.

[00124] Meanwhile, in the method provided by the present embodiment, when performing resource reselection for an initial transmission resource in conflict, based on the reassessment, the terminal determines a time-frequency resource that is close to the original initial transmission resource in the time domain , from the remaining resources after excluding the resource as a reselection resource. Since the position of the initial transmission resource is located between the time n and the time n+p, the case where the position of the reselection resource in the time domain is relatively behind in the resource selection window is avoided, and timely transmission of the service is again guaranteed.

[00125] In an exemplary embodiment based on FIG. 10, fig. 13 is a flow diagram of a resource selection method in a V2X system provided by an exemplary embodiment of the present application. In the present embodiment, the method further includes step 1002.

[00126] In step 1002, a retransmission resource for a service is selected from a resource selection window, with the retransmission resource located after the initial transmission resource.

[00127] Optionally, the terminal excludes resources from the resource selection window to obtain candidate resources in the resource selection window based on the listening result of the resource listening window, and selects a retransmission resource for the service from the candidate resources. In the retransmission resource, the terminal transmits the service to the terminal to re-receive the service.

[00128] Optionally, there are two resource relay modes: HARQ feedback and blind retransmission.

[00129] Blind retransmission means that the terminal selects a plurality of time frequency resources at the same time and sends the same data of one service each time, and the terminal for receiving the service does not feedback for each transmission of the terminal, but only combines the received data.

[00130] HARQ feedback means that the terminal simultaneously selects a plurality of time-frequency resources and sends the same data each time. For each transmission, the receiving terminal returns an ACK/NACK to the terminal depending on whether the reception was successful or not, with ACK representing a successful reception and NACK representing a failed reception. After the terminal receives the ACK, it stops sending data and releases the time-frequency resources that have not been used. The receiving terminal performs HARQ feedback to the terminal via the PSFCH, i. e. feedback channel through a direct link connection.

[00131] There are two cases of HARQ feedback activation for resource retransmission.

[00132] Case 1: A retransmission resource for a service is determined from a resource selection window when hybrid automatic repeat request (HARQ) feedback is active and a terminal to receive the service is allowed to perform 1-bit HARQ feedback for the same PSFCH resource on for at least two current TB transmissions by the terminal.

[00133] Case 2: A retransmission resource for a service is determined from a resource selection window when hybrid automatic repeat request (HARQ) feedback is active and a terminal to receive the service is allowed to perform 1-bit HARQ feedback for the same PSFCH resource for one transmission by the terminal of the current TB.

[00134] The above case 1 of HARQ feedback activation or blind retransmission activation is that the terminal for receiving the service returns information on multiple transmissions of the current TB, and there is no required time interval between two adjacent transmissions.

[00135] For case 1 of activating HARQ feedback or activating blind retransmission, the terminal determining the retransmission resource for the service from the resource selection window includes determining the retransmission resource for the service with equal probability from the candidate resources of the resource selection window.

[00136] The retransmission resource is located after the resource selected for the last transmission of the current TB, and the candidate resources are the set of resources that have not been excluded from the resource selection window.

[00137] For example, with reference to FIG. 14, there is a service to be transmitted at time n, and the terminal excludes the corresponding time-frequency resources from the selection window n+T ₁ to n+T ₂ based on the listening result of the listening window from time nT ₀ to time n. The remaining resources in the resource selection window are used as candidate resources, and all candidate resources form resource set A, including resources {x, y, z, m, n, j, g, h} in FIG. 9. The resource pool is assumed to be configured with N=4 (ie every four slots configured with a PSFCH resource) and k=2. The terminal performs one initial transmission and two retransmissions for the current TB.

[00138] The terminal first selects an initial transmission resource between time n and time n+p, then the terminal randomly selects an initial transmission resource from the set of resources {x, y} with equal probability, and it is assumed that the terminal selects resource x as initial transmission resource.

[00139] The terminal activates HARQ feedback case 1 or activates blind retransmission and randomly selects the remaining two retransmissions from the resource set {y, z, m, n, j, g, h}.

[00140] For HARQ feedback activation case 2, the receiving terminal returns feedback for one transmission of the current TB, and at least one PSFCH resource must be included between two adjacent transmissions, so a PSFCH resource is present between the retransmission resource and the resource selected for the last transmission of the current TB.

[00141] In one example, the time when the retransmission resource is greater than the time n+ a + Q, where n+ a is the time when the terminal for receiving the service performs HARQ feedback for the last transmission of the current TB, and Q represents is the length of processing time required by the terminal from receiving the HARQ feedback to sending the next transmission.

[00142] Optionally, the PSFCH resource is included in slot n+ a , and through the PSFCH resource, the terminal to receive the service performs HARQ feedback on the last transmission of the current TB by the terminal, where a is greater than or equal to k and k occupies 2 or 3 slots in NR-V2X .

[00143] For example, with reference to FIG. 14, based on the slot in which the selected initial transmission resource x is located and the resource pool configuration, the terminal calculates that in slot n+α, the receiving terminal performs HARQ feedback on the initial transmission of the terminal.

[00144] The terminal selects a resource for the first retransmission between slot n+α+Q (excluding this slot) and time n+T ₂ , i.e., the terminal randomly selects a resource for the first retransmission from the set of resources {z, m , n, j , g, h}, and the terminal is assumed to select resource z. Thereafter, based on the slot in which resource z is located and the resource pool configuration, the terminal calculates that in slot n+β, the receiving terminal performs HARQ feedback on the terminal's first retransmission. The terminal then selects a resource for the second retransmission between slot n+β+Q (excluding this slot) and time n+T ₂ , i.e., the terminal selects a resource for the second retransmission from the resource set {j, g, h} , and the terminal finally selects resource h as the resource for the second retransmission. When there is no resource in set A included between slot n+β+Q (excluding this slot) and time n+T ₂ , the terminal refuses the second retransmission.

[00145] In one example, the terminal reassesses the retransmission resource; and when a contention occurs in the retransmission resource, the terminal determines the second reselection resource for the retransmission resource from the second reselection window.

[00146] The second reselection window is a window from time n+t ₂ +T ₃₁ to time n+t ₂ +T ₃₂ , the second reselection resource is a time-frequency resource in candidate resources of the second reselection window, which has a distance from the retransmission resource less than or equal to the distance i , wherein i is an integer of at least 0, the time n+t ₂ is the time when it is determined that a collision occurs in the retransmission resource, and the candidate resources are the set of resources in the second reselection window that were not excluded after being excluded based on the result of listening to the resource listening window.

[00147] It should be noted that if there is more than one time-frequency resource in the candidate resources of the second reselection window, the distance from which to the retransmission resource is less than or equal to the distance i, the terminal selects one time-frequency resource among them as the second resource reselection with equal probability.

[00148] Optionally, the first time period from time n+t ₂ to time n+t ₂ +T ₃₁ is greater than or equal to the terminal processing delay, and the second time period from time n to time n+t ₂ +T ₃₂ is less than or equal to the required service delay range.

[00149] For example, t ₂ is 500 ms, and the terminal determines that a collision occurs in the retransmission resource at n+500 ms; the terminal processing delay is 10 ms, and the first time period from time n+t2 to time n+t ₂ +T ₃₁ is equal to the terminal processing delay, which is also 10 ms; and the required service delay range is 1000 ms, the second time period from time n to time n+t ₂ +T ₃₂ is equal to the required service delay range, and T ₃₂ is 500 ms. The second reselection window is a window from time n+t ₂ +10 to time n+t ₂ +500.

[00150] Collision occurring in the retransmission resource means that during reassessment, the retransmission transmission resource selected by the terminal is also reserved by the other terminal as an initial transmission resource or a retransmission resource for transmitting another service.

[00151] Optionally, when a conflict occurs in the retransmission resource of UE1, the UE1 measures the RSRP of the other UE2 in conflict, and only when the measured UE2 RSRP is higher than the UE1 RSRP threshold and the UE2 priority is higher than its own priority ( the priority carried in the PSCCH of UE2 is higher than the priority of the overhead to be transmitted by the UE1), the UE1 reselects the resource to determine the second reselect resource. The aforementioned RSRP threshold is determined by the priority carried in the PSCCH listened by UE1 and the priority of the overhead to be transmitted.

[00152] After determining that a collision occurs in the retransmission resource, the terminal releases the retransmission resource, determines a window from time n+t ₂ +T ₃₁ to time n+t ₂ +T ₃₂ as the second reselection window, and excludes resources from the second reselection window based on the listening result of the second resource listening window to obtain candidate resources, the exclusion process being described above. The second resource listening window is a window from time n+t ₂ -T ₀ to time n+t ₂ .

[00153] Referring to FIG. 15, determining the second reselection resource for the retransmission resource from the second reselection window may include the following steps.

[00154] In step 1501, a second slot interval from s ₂ - i to s ₂ + i is determined, where s ₂ is the slot corresponding to the retransmission resource, and the initial value of i is R ₂ , where R ₂ is an integer a number of at least 0.

[00155] In step 1502, when candidate resources located in the second slot interval are present in the second reselection window, a second reselection resource is determined with equal probability from the candidate resources located in the second slot interval.

[00156] In step 1503, when a candidate resource located in the second slot interval is not present in the second reselection window, determination of the second slot interval s ₂ - i to s ₂ + i is performed again after i is added to one.

[00157] Optionally, the second reselection resource and the resource that was selected are located at different times, and the resource that was selected is the resource selected by the terminal for another transmission of the current TB.

[00158] If resource m is a retransmission resource selected by the terminal for another retransmission of the current TB, then the terminal does not take resource m as the second reselection resource when performing reselection of the retransmission resource.

[00159] For example, with reference to FIG. 16, there is a service to be transmitted by the terminal at time n. The terminal completes resource selection and selects resource x, resource m, and resource j on fig. 16 as transmission resources (including initial transmission and retransmission).

[00160] At time n+t, the terminal learns that resource m conflicts with a resource reserved by another terminal through reassessment, and the terminal needs to perform resource reselection for resource m. The terminal excludes the corresponding time-frequency resource from the resource selection window n+t+T ₁ to n+t+T ₂ based on the listening result of the resource listening window from time n+tT ₀ to time n+t. In addition, the terminal excludes all resources in the slot containing resource x and resource j. The remaining resources in the resource selection window are used as candidate resources, and all candidate resources form resource set A, including resources {y, z, g, n, h} in FIG. 16. The resource pool configuration is assumed to be N=4 and k=2. The terminal performs one initial transmission and two retransmissions for the current TB. The terminal needs Q slots to perform the next transmission after receiving the HARQ feedback.

[00161] Resource m is located in slot n+α, and the terminal reselects the resource for resource m.

[00162] The terminal first sets i to 0, i.e. the terminal looks for a resource that belongs to resource set A in slot n+α. If the resource belonging to resource set A is not found in slot n+α, then the terminal adds 1 to i, i.e., the terminal looks for a resource belonging to resource set A in slot n+α-1 and slot n+α+1 . The terminal finds resource g and selects resource g as reselection resources for resource m.

[00163] Thus, a terminal for receiving a service may perform 1-bit HARQ feedback for one PSFCH resource for multiple transmissions by the terminal of the current service, or may perform 1-bit HARQ feedback for one PSFCH resource for one transmission of the current service by the terminal, so the method provided by the present embodiment provides appropriate resource selection decisions that are dedicated to these two cases, respectively.

[00164] Meanwhile, in the method of the present embodiment, when performing resource reselection for an initial transmission resource in conflict, based on the reassessment, the terminal determines a time-frequency resource that is close to the original retransmission resource in the time domain , of the remaining resources after deleting the resource as a reselection resource, so that the case where the position of the reselection resource in the time domain is relatively behind in the resource selection window is eliminated, and timely transmission of the service is again guaranteed.

[00165] FIG. 17 is a block diagram of a device for selecting resources in a V2X system provided by an exemplary embodiment of the present application, and the device includes: a determination unit 1701.

[00166] The determination module 1701 is configured, if there is a service to be transmitted at time n, to select an initial transmission resource for the service from a resource selection window, with the initial transmission resource located between time n and time n+p.

[00167] The resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, the second time period from time time n to time n+T ₁₂ is less than or equal to the required service delay range, and the value p is less than the predetermined value W.

[00168] In one example, the definition module 1701 is configured to define a resource listening window and a resource selection window; the determination module 1701 is configured to exclude resources from the resource selection window based on a listening result of the resource listening window to obtain candidate resources in the resource selection window; and the determination module 1701 is configured to select an initial transmission resource for the service from the candidate resources.

[00169] In one example, the device further comprises a listening module 1702; the listening module 1702 is configured to re-evaluate the initial transmission resource; the determination module 1701 is configured to determine a first reselection resource for the initial transmission resource from the first reselection window when a conflict occurs in the initial transmission resource; and wherein the first reselection window is a window from time n+t ₁ +T ₂₁ to time n+t ₁ +T ₂₁ , the first reselection resource is a frequency-time resource in the candidate resources of the first reselection window, which has a distance from the initial transmission resource less than or equal to the distance i , wherein i is an integer greater than or equal to 0, the time n+t ₁ is the point at which it is determined that a collision occurs in the initial transmission resource, and the candidate resources are the set of resources in the first reselection window that were not excluded after being excluded based on the resource listening window's listening result.

[00170] In one example, determination module 1701 is configured to determine a first slot interval from s ₁ -i to s ₁ + i, wherein s ₁ is the slot corresponding to the initial transmission resource and the initial value of i is R ₁ , wherein R ₁ is an integer not less than 0; the determination module 1701 is configured to, when a candidate resource located in the first slot interval is present in the first reselection window, to determine the first reselection resource with equal probability from the candidate resource located in the first slot interval; and the determination module 1701 is configured, when the candidate resource located in the first slot interval is not present in the first reselection window, to perform the step of determining the first slot interval from s ₁ - i to s ₁ + i again after i unit will be added.

[00171] In one example, the first reselection resource and the resource that was selected are located at different times, and the selected resource is the resource selected by the terminal for another transmission of the current TB.

[00172] In one example, the determination module 1701 is configured to select a retransmission resource for a service from a resource selection window, with the retransmission resource located after the initial transmission resource.

[00173] In one example, determining module 1701 is configured when hybrid automatic repeat request (HARQ) feedback is active and a terminal for receiving a service is allowed to perform 1-bit HARQ feedback for the same PSFCH resource for at least two transmissions of the current TB by the terminal, determining a retransmission resource for the service from the resource selection window.

[00174] In one example, determination module 1701 is configured, when blind retransmission is active, to determine a retransmission resource for a service from a resource selection window.

[00175] In one example, the determination module 1701 is configured to determine a retransmission resource for a service with equal probability from the resource selection window candidate resources; wherein the retransmission resource is located after the resource selected for the last transmission of the current TB, and the candidate resources are the set of resources in the first reselection window that have not been excluded.

[00176] In one example, determining module 1701 is configured, when hybrid automatic repeat request (HARQ) feedback is active and a terminal for receiving a service is allowed to perform 1-bit HARQ feedback for one PSFCH resource for one transmission of the current TB by the terminal, determining a retransmission resource for the service from the resource selection window; and wherein the PSFCH resource is located between the retransmission resource and the resource selected for the last transmission of the current TB.

[00177] In one example, the time when the retransmission resource is greater than time n+ a+Q, where n+ a is the time when the terminal for receiving the service performs HARQ feedback on the last transmission of the current TB by the terminal, and Q is the length of processing time it takes the terminal from receiving the HARQ feedback to sending the next transmission.

[00178] In one example, the listening module 1702 is configured to re-evaluate the retransmission resource; the determination module 1701 is configured, when a conflict occurs in the retransmission resource, to determine a second reselection resource for the retransmission resource from the second reselection window; and the second reselection window is the window from time n+t₂+T₃₁ up to time n+t₂+T₃₂, the second reselection resource is a time-frequency resource in the candidate resources of the second reselection window that has a distance from the reselection resource transmission less than or equal to the distancei, whereini is an integer not less than 0, time n+t₂ is the point in time when it is determined that a collision occurs in the retransmission resource, and the candidate resources are the set of resources in the second reselection window that were not excluded after being excluded based on the resource's listening window's listening result.

[00179] In one example, the module 1701 Definitions are made with the possibility of determining the second interval of slots from S₂-i to s₂+i, while s₂ is a slot corresponding to the retransmission resource, and the initial valuei It is R.₂, R₂ is an integer, not less than 0; The module 1701 Definitions are made with the possibility when the resource-gun, located in the second interval of the slots, is present in the second window of re-choice, determining the second resource of re-choice with equal probability from the resource-candidate located in the second interval of slots; and the module 1701 Definitions are made with the possibility when the resource of the Candate located in the second interval of the slots is not present in the second second-selection window, again to determine the stage of determining the second interval of slots from S₂-i tos ₂ +I afteri A unit is added.

[00180] In one example, the second reselection resource and the resource that was selected are located at different times, and the selected resource is the resource selected by the terminal for another transmission of the current TB.

[00181] FIG. 18 is a block diagram of a device for selecting resources in a V2X system provided by an exemplary embodiment of the present application, and the device includes: a determination module 1801.

[00182] The determination module 1801 is configured, when there is a service to be transmitted at time n, to select a retransmission resource for the service from a resource selection window, with the retransmission resource located after the start resource.

[00183] The resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time T ₁₁ is greater than or equal to the terminal processing delay, the second time period from time n up to time n+T ₁₂ is less than or equal to the required service delay range.

[00184] In one example, determining module 1801 is configured when hybrid automatic repeat request (HARQ) feedback is active and a terminal for receiving a service is allowed to perform 1-bit HARQ feedback for the same PSFCH resource for at least two transmissions of the current TB by the terminal, determining a retransmission resource for the service from the resource selection window.

[00185] In one example, determining module 1801 is configured to determine a retransmission resource for a service from a resource selection window when blind retransmission is active.

[00186] In one example, determining module 1801 is configured to determine a retransmission resource for an equal probability service from candidate resources of a resource selection window; wherein the retransmission resource is located after the resource selected for the last transmission of the current TB, and the candidate resources are a set of resources that have not been excluded from the resource selection window.

[00187] In one example, determining module 1801 is configured, when hybrid automatic repeat request (HARQ) feedback is active and a terminal to receive a service is allowed to perform 1-bit HARQ feedback for one PSFCH resource for one transmission of the current TB by the terminal, determining a retransmission resource for the service from the resource selection window; wherein the PSFCH resource is located between the retransmission resource and the resource selected for the last transmission of the current TB.

[00188] In one example, the time when the retransmission resource is greater than the time n+a+Q, whilen+a is the point in time when the terminal for receiving the service performs HARQ feedback for the last transmission of the current TB by the terminal, and Q is the length of processing time required by the terminal from receiving the HARQ feedback to sending the next transmission.

[00189] In one example, the device further includes: a listening module 1802; the listening module 1802 is configured to continuously reassess the retransmission resource; the determination module is configured, when a conflict occurs in the retransmission resource, to determine a second reselection resource for the retransmission resource from the second reselection window; and the second reselection window is the window from time n+t₂+T₃₁ up to time n+t₂+T₃₂, the second reselection resource is a time-frequency resource in the second reselection window candidate resources that has a distance from the retransmission resource less than or equal to the distancei, whereini is an integer not less than 0, time n+t₂ is the point in time when it is determined that a collision occurs in the retransmission resource, and the candidate resources are the set of resources in the second reselection window that were not excluded after being excluded based on the resource listening window's listening result.

[00190] In one example, determination module 1801 is configured to determine a second slot interval from s₂-i to s₂+i, while s₂ is the slot corresponding to the retransmission resource, and the initial valuei is R₂, and R₂ is an integer, not less than 0; the determination module 1801 is configured, when a candidate resource located in the second slot interval is present in the second reselection window, to determine a second reselection resource with equal probability from the candidate resource located in the second slot interval; and the determination module 1801 is configured, when a candidate resource located in the second slot interval is not present in the second reselection window, to perform again determination of the second slot interval from s₂-i to s₂+i after one is added to i.

[00191] In one example, the second reselection resource and the resource that was selected are located at different times, and the selected resource is the resource selected by the terminal for another transmission of the current TB.

[00192] Fig. 19 is a block diagram of a transmitting terminal provided by an exemplary embodiment of the present application, and a communication device includes a processor 101, a receiver 102, a transmitter 103, a memory 104, and a bus 105.

[00193] The processor 101 includes one or more computing cores and performs various functional applications and information processing by running programs and software modules.

[00194] Receiver 102 and transmitter 103 may be implemented as a single communications component, which may be part of a communications chip.

[00195] Memory 104 is connected to processor 101 via bus 105.

[00196] The memory 104 may be configured to store at least one instruction, and the processor 101 may be configured to execute at least one instruction to implement the individual steps in the above method embodiments.

[00197] In addition, the memory 104 can be implemented by any type of volatile or non-volatile storage devices or a combination thereof, including, but not limited to, a magnetic disk or optical disk, erasable programmable read-only memory (EEPROM, erasable programmable read only memory), erasable programmable read-only memory (EPROM, erasable programmable read only memory), static random access memory (SRAM, static random access memory), read-only memory (ROM), magnetic memory, flash memory and programmable read-only memory (PROM, programmable Read-Oly Memory).

[00198] An exemplary embodiment also provides a computer-readable storage medium that stores at least one instruction, at least one program, set of codes, or set of instructions, wherein at least one instruction, at least one program, set codes or instruction set is loaded and executed by the processor to implement the V2X system resource selection method performed by the transmitting terminal provided by the above method embodiments.

[00199] Those skilled in the art will appreciate that all or part of the steps for implementing the above embodiments may be performed by hardware or by instructing the appropriate hardware through a program, wherein the program may be stored on a computer-readable storage medium, and said above, the storage medium may be a read-only memory, a magnetic disk, or an optical disk.

[00200] The foregoing is only possible embodiments of the present application and is not intended to limit the present application. All modifications, equivalent replacements, improvements, etc. made in the spirit and principle of this application are to be included within the scope of protection of this application.

Claims (35)

1. A method for selecting resources in connection with a direct connection, the method comprising: if there is a service to be transmitted at time n, selecting a retransmission transmission resource for the service from the resource selection window, the retransmission transmission resource being located after the initial transmission resource for the service; wherein the resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, and the second time period from time time n until time n+T ₁₂ is less than or equal to the required service delay range. 2. The method of claim 1, wherein selecting a retransmission resource for a service from a resource selection window comprises: when the hybrid automatic repeat request (HARQ) feedback is in the active state and the terminal is allowed to perform 1-bit HARQ feedback for the same PSFCH resource for at least two transmissions of the current TB by the terminal to receive the service, determining the retransmission resource for services from the resource selection window. 3. The method of claim 1, wherein selecting a retransmission resource for a service from a resource selection window comprises: when blind retransmission is in the active state, determining the retransmission resource for the service from the resource selection window. 4. The method of claim 2 or 3, wherein determining the retransmission resource for the service from the resource selection window comprises: determining a retransmission resource for the service with equal probability among the candidate resources in the resource selection window; wherein the retransmission resource is located after the resource selected for the last transmission of the current TB, and the candidate resources are the set of resources in the resource selection window that were not excluded after being excluded based on the resource listening window listening result. 5. The method of claim 1, wherein selecting a retransmission resource for a service from a resource selection window comprises: when the hybrid automatic retransmission request (HARQ) feedback is in the active state and the terminal for receiving the service is allowed to perform HARQ feedback for one PSFCH resource for one transmission of the current TB by the terminal, determining the retransmission resource for the service from the resource selection window; wherein the PSFCH resource is present between the retransmission resource and the resource selected for the last transmission of the current TB. 6. The method of claim 5, wherein the time at which the retransmission resource is located is greater than time n+ a+ Q, wherein n+ a is the time when the terminal performs HARQ feedback for the last transmission of the current TB by the terminal to receive the service, and Q is the length of processing time it takes the terminal from receiving the HARQ feedback to sending the next transmission. 7. The method of claim 5, wherein selecting a retransmission resource for a service from a resource selection window comprises: when the HARQ feedback is in the active state and the terminal is allowed to perform 1-bit HARQ feedback for one PSFCH resource for one transmission of the current TB by the terminal to receive the service, determining the retransmission resource for the service from the resource selection window. 8. A device for selecting resources in connection with a direct connection, the device comprising: a definition module; the determination module is configured, if there is a service to be transmitted at time n, to select a retransmission transmission resource for the service from a resource selection window, the retransmission transmission resource being located after the initial transmission resource for the service; And wherein the resource selection window is a window from time n+T ₁₁ to time n+T ₁₂ , the first time period from time n to time n+T ₁₁ is greater than or equal to the terminal processing delay, and the second time period from time time n until time n+T ₁₂ is less than or equal to the required service delay range. 9. The device according to claim 8, in which: the determining module is configured when the hybrid automatic repeat request (HARQ) feedback is in the active state and the terminal is allowed to perform 1-bit HARQ feedback for the same PSFCH resource for at least two current TB transmissions by the terminal to receive the service , determining a retransmission resource for the service from the resource selection window. 10. The device according to claim 8, in which: the determination module is configured, when the blind retransmission is in the active state, to determine the retransmission resource for the service from the resource selection window. 11. The device according to claim 9 or 10, in which the determination module is configured to determine a retransmission resource for the service with equal probability from the candidate resources in the resource selection window; And wherein the retransmission resource is located after the resource selected for the last transmission of the current TB, and the candidate resources are the set of resources in the resource selection window that were not excluded after being excluded based on the resource listening window listening result. 12. The device according to claim 8, in which: the determining module is configured, when the hybrid automatic retransmission request (HARQ) feedback is in the active state and the terminal for receiving the service is allowed to perform HARQ feedback for one PSFCH resource for one transmission of the current TB by the terminal, determining the retransmission resource for the service from the window resource selection; And wherein the PSFCH resource is present between the retransmission resource and the resource selected for the last transmission of the current TB. 13. The device according to claim 12, in which the time at which the retransmission resource is located is greater than the time n + a + Q, while n+a is is the point at which the terminal for receiving the service performs HARQ feedback for the last transmission of the current TB by the terminal, and Q is the processing time required by the terminal from receiving the HARQ feedback to sending the next transmission. 14. The device according to claim 12, in which the determination module is configured, when the HARQ feedback is in the active state and the terminal to receive the service is allowed to perform 1-bit HARQ feedback for one PSFCH resource for one transmission of the current TB by the terminal, to determine the retransmission resource for the service from the resource selection window. 15. A computer-readable storage medium in which executable instructions are stored on a readable storage medium and executable instructions are loaded and executed by the processor to implement the resource selection method in connection with a direct connection according to any one of paragraphs. 1-7.

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