WO2019084925A1

WO2019084925A1 - Carrier selection method in d2d communication and terminal device

Info

Publication number: WO2019084925A1
Application number: PCT/CN2017/109401
Authority: WO
Inventors: 唐海
Original assignee: Oppo广东移动通信有限公司
Priority date: 2017-11-03
Filing date: 2017-11-03
Publication date: 2019-05-09
Also published as: CN110741708B; CN110741708A

Abstract

The present application discloses a carrier selection method in D2D communication, and a terminal device. Said method comprises: a terminal device acquiring a channel occupying ratio (CBR) of a plurality of carriers in a subframe [n-P, n-P+(T-1)], T being a delay of a target service to be transmitted, and the subframe n being the moment when the target service arrives, or determining for the terminal device the moment when carrier selection or resource selection needs to be performed; the terminal device performing, in the plurality of carriers, carrier selection according to the CBR of the plurality of carriers, so as to acquire a target carrier for transmitting the target service. Therefore, the terminal device can enable effective carrier selection while satisfying delay requirements.

Description

Carrier selection method and terminal device in D2D communication

Technical field

The embodiments of the present application relate to the field of wireless communications, and in particular, to a method and a terminal device for selecting carriers in Device to Device (D2D) communication.

Background technique

Vehicle networking or Vehicle to Everything (V2X) communication system is a sidelink (SL) transmission technology based on Device to Device (D2D) communication, with traditional long-term evolution ( In the Long Term Evolution (LTE) system, the way in which the base station receives or transmits data is different. The vehicle networking system adopts a terminal-to-terminal direct communication method, and thus has higher spectrum efficiency and lower transmission delay.

In a car network system supporting multi-carrier transmission, a terminal device may perform current data transmission using one or more of the candidate multiple carriers. Therefore, how to select a carrier by a terminal device or a base station becomes an urgent problem to be solved.

Summary of the invention

The embodiment of the present application provides a carrier selection method and a terminal device in D2D communication, and the terminal device can effectively perform carrier selection while satisfying a delay requirement.

In a first aspect, a method for carrier selection in D2D communication is provided, comprising: acquiring, by a terminal device, a channel occupancy ratio CBR of a plurality of carriers in a subframe [nP, n-P+(T-1)], where T is The time delay of the target service to be transmitted, P is a positive integer, the subframe n is the time when the target service arrives, or the time at which the terminal device needs to perform carrier selection or resource selection; the terminal device according to the The CBR of the multiple carriers performs the carrier selection in the multiple carriers to obtain a target carrier for transmitting the target service.

Therefore, in the embodiment of the present application, the terminal device selects, according to the delay T of the target service to be transmitted, according to the channel occupancy ratio CBR of the multiple carriers in the subframe [nP, n-P+(T-1)]. The target carrier of the target service is transmitted, so that effective carrier selection can be realized under the condition that the delay requirement is met.

Optionally, the P may be a period for performing carrier selection or resource selection. For example, if the subframe n is the time at which the terminal device determines that carrier selection or resource selection is required, the n-P can recognize In order to determine that the terminal device needs to perform carrier selection or resource selection last time, P is, for example, 100 ms.

In a possible implementation, the terminal device performs the carrier selection in the multiple carriers according to the CBR of the multiple carriers, where the terminal device separately performs CBR on the multiple carriers. Performing a filtering process to obtain a filtered CBR of the plurality of carriers; and selecting the target carrier among the plurality of carriers according to the filtered CBR of the multiple carriers.

In a possible implementation manner, the performing filtering processing on the CBRs of the multiple carriers separately includes: performing smoothing filtering on CBRs of the multiple carriers, respectively.

In a possible implementation, the CBR of each of the plurality of carriers after the smoothing is performed is: CBR_new=a×CBR_old+(1-a)×CBR_current,

The CBR_new is the CBR of each carrier after the filtering, and the CBR_current is the CBR of each carrier before the filtering, and the CBR_old is the CBR of each carrier after the last filtering, a is a filter coefficient and 0≤a≤ 1.

In a possible implementation, the terminal device performs the carrier selection in the multiple carriers according to the CBR of the multiple carriers, including: the terminal device according to the CBR of the multiple carriers, A carrier having a smallest CBR is selected as the target carrier among the plurality of carriers.

In a second aspect, a method for carrier selection in D2D communication is provided, which includes: a physical layer of a terminal device performs resource sensing on multiple carriers in a time interval [n+T1, n+T2], where n is to be transmitted. The time at which the target service arrives, or the time at which the terminal device needs to perform carrier selection or resource selection, 0 ≤ T1 < T2; the physical layer of the terminal device determines the multiple according to the result of the resource interception a set of available resources on the carrier that can be used to transmit the target service, and a plurality of physical side-link shared channel reference signal received power PSSCH-RSRP thresholds corresponding to the multiple carriers, wherein available resources on each carrier The PSSCH-RSRP of the resource in the set is less than or equal to the PSSCH-RSRP threshold corresponding to each carrier; the terminal device performs the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain A target carrier for transmitting the target service.

Therefore, in the embodiment of the present application, the terminal device may obtain multiple PSSCH-RSRP thresholds corresponding to the multiple carriers in the process of determining the available resource set on the multiple carriers, and according to the multiple corresponding to the multiple carriers, The PSSCH-RSRP threshold effectively implements carrier selection, so that a terminal device in a system supporting multi-carrier transmission can acquire resources in the selected carrier for data transmission.

In a possible implementation manner, the terminal device determines, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a target carrier for transmitting the target service, where: the physical layer of the terminal device is based on And a plurality of PSSCH-RSRP thresholds corresponding to the multiple carriers, and selecting, as the target carrier, a carrier with a minimum PSSCH-RSRP threshold among the multiple carriers.

In a possible implementation, the method further includes: the physical layer of the terminal device reports the available resource set on the target carrier to a higher layer of the terminal device, and/or the terminal device The physical layer reports the index of the target carrier to the upper layer of the terminal device; the upper layer of the terminal device selects a resource for transmitting the target service in the available resource set on the target carrier.

In a possible implementation, the terminal device determines, according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a target carrier for transmitting the target service, including: physical layer orientation of the terminal device The higher layer of the terminal device reports multiple PSSCH-RSRP thresholds corresponding to the multiple carriers; the higher layer of the terminal device selects among the multiple carriers according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers The carrier with the smallest PSSCH-RSRP threshold is used as the target carrier.

In a possible implementation manner, the method further includes: reporting, by a physical layer of the terminal device, a set of available resources on the multiple carriers to a higher layer of the terminal device; Among the available resource sets on the target carrier, resources for transmitting the target service are selected.

In a possible implementation manner, T2 is less than or equal to the delay of the target service.

In a third aspect, a terminal device is provided, which can perform the operations of the terminal device in the above first aspect or any optional implementation manner of the first aspect. In particular, the terminal device may comprise a modular unit for performing the operations of the terminal device in any of the possible implementations of the first aspect or the first aspect described above.

A fourth aspect provides a terminal device, which can perform the operations of the terminal device in any of the foregoing optional implementations of the second aspect or the second aspect. In particular, the terminal device may comprise a modular unit for performing the operations of the terminal device in any of the possible implementations of the second aspect or the second aspect described above.

In a fifth aspect, a terminal device is provided, the terminal device comprising: a processor, a transceiver, and a memory. The processor, the transceiver, and the memory communicate with each other through an internal connection path. The memory is for storing instructions for executing instructions stored by the memory. When the process When the instruction is executed by the memory, the execution causes the terminal device to perform the method of the first aspect or any possible implementation of the first aspect, or the execution causes the terminal device to implement the terminal device provided by the third aspect.

In a sixth aspect, a terminal device is provided, the terminal device comprising: a processor, a transceiver, and a memory. The processor, the transceiver, and the memory communicate with each other through an internal connection path. The memory is for storing instructions for executing instructions stored by the memory. When the processor executes the instruction stored by the memory, the executing causes the terminal device to perform the method in any of the possible implementations of the second aspect or the second aspect, or the execution causes the terminal device to implement the terminal provided by the fourth aspect device.

In a seventh aspect, a computer readable storage medium is provided, the computer readable storage medium storing a program causing a terminal device to perform the first aspect described above, and any one of the various implementations of the D2D communication Medium carrier selection method.

In an eighth aspect, a computer readable storage medium is provided, the computer readable storage medium storing a program causing the terminal device to perform the second aspect described above, and any one of the various implementations of the D2D communication Medium carrier selection method.

In a ninth aspect, a system chip is provided, the system chip comprising an input interface, an output interface, a processor, and a memory, the processor is configured to execute an instruction stored by the memory, and when the instruction is executed, the processor can implement the foregoing The method of any of the first aspect or any of the possible implementations of the first aspect.

According to a tenth aspect, a system chip is provided, the system chip includes an input interface, an output interface, a processor, and a memory, the processor is configured to execute an instruction stored by the memory, and when the instruction is executed, the processor can implement the foregoing The method of any of the second aspect or any possible implementation of the second aspect.

In an eleventh aspect, a computer program product comprising instructions for causing a computer to execute the method of any of the first aspect or the first aspect of the first aspect, when the computer program product is run on a computer.

According to a twelfth aspect, there is provided a computer program product comprising instructions which, when executed on a computer, cause the computer to perform the method of any of the second aspect or the second aspect of the second aspect.

DRAWINGS

FIG. 1 is a schematic structural diagram of an application scenario of an embodiment of the present application.

FIG. 2 is a schematic structural diagram of another application scenario of the embodiment of the present application.

Figure 3 is a schematic diagram of resource listening and selection.

FIG. 4 is a schematic flowchart of a method for carrier selection according to an embodiment of the present application.

FIG. 5 is a schematic flowchart of a method for carrier selection according to another embodiment of the present application.

FIG. 6 is a schematic block diagram of a terminal device according to an embodiment of the present application.

FIG. 7 is a schematic block diagram of a terminal device according to another embodiment of the present application.

FIG. 8 is a schematic structural diagram of a communication device according to an embodiment of the present application.

FIG. 9 is a schematic structural diagram of a system chip according to an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as a Global System of Mobile Communication (GSM) system, a Code Division Multiple Access (CDMA) system, and a wideband code. Wideband Code Division Multiple Access (WCDMA) system, Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) , Universal Mobile Telecommunication System (UMTS), and future 5G communication systems.

The present application describes various embodiments in connection with a terminal device. The terminal device may also refer to a user equipment (User Equipment, UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, and a user agent. Or user device. The access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), with wireless communication. Functional handheld devices, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, terminal devices in future 5G networks, or future evolved land-based public land mobile network (PLMN) networks Terminal equipment, etc.

The present application describes various embodiments in connection with a network device. The network device may be a device for communicating with the terminal device, for example, may be a GSM system or a base station in CDMA (Base The Transceiver Station (BTS) may also be a base station (NodeB, NB) in the WCDMA system, or may be an evolved base station (Evolutional Node B, eNB or eNodeB) in the LTE system, or the network device may be a relay station or an access station. Point, in-vehicle device, wearable device, and network side device in a future 5G network or network side device in a future evolved PLMN network.

FIG. 1 and FIG. 2 are schematic diagrams of an application scenario of an embodiment of the present application. FIG. 1 exemplarily shows one network device and two terminal devices. Alternatively, the wireless communication system may include a plurality of network devices and may include other numbers of terminal devices within the coverage of each network device, the present invention The embodiment does not limit this. In addition, the wireless communication system may further include other network entities such as a Mobile Management Entity (MME), a Serving Gateway (S-GW), and a Packet Data Network Gateway (P-GW). However, embodiments of the invention are not limited thereto.

Specifically, the terminal device 20 and the terminal device 30 can communicate in a D2D communication mode. When performing D2D communication, the terminal device 20 and the terminal device 30 directly communicate through a D2D link, ie, a side link (Sidelink, SL). For example, as shown in FIG. 1 or FIG. 2, the terminal device 20 and the terminal device 30 directly communicate via a side line. In FIG. 1, the terminal device 20 and the terminal device 30 communicate by a side line, and the transmission resources thereof are allocated by the network device; in FIG. 2, the terminal device 20 and the terminal device 30 pass the side link. Communication, whose transmission resources are independently selected by the terminal device, does not require the network device to allocate transmission resources.

The D2D communication may refer to a vehicle to vehicle (V2V) communication or a vehicle to Everything (V2X) communication. In V2X communication, X can refer to any device with wireless receiving and transmitting capabilities, such as but not limited to slow moving wireless devices, fast moving in-vehicle devices, or network control nodes with wireless transmit and receive capabilities. It should be understood that the embodiment of the present invention is mainly applied to the scenario of V2X communication, but can also be applied to any other D2D communication scenario, which is not limited in this embodiment of the present invention.

In a car network system, there may be two types of terminal devices, namely, a terminal device having a listening capability such as a Vehicle User Equipment (VUE) or a Pedestrian User Equipment (PUE), and no listening. Capable terminal equipment such as PUE. VUE has higher processing power and is usually powered by the battery in the car, while PUE has lower processing power, and reducing power consumption is also a major factor that PUE needs to consider. Therefore, in the existing car network system, VUE is considered to have Full reception and listening capabilities; while PUE is considered to have partial or no reception and listening capabilities. If the PUE has partial listening capabilities, The resource selection may be performed by using a similar listening method as the VUE, and the available resources are selected on the part of the resources that can be intercepted; if the PUE does not have the listening capability, the PUE randomly selects the transmission resource in the resource pool.

In Release-14 of the 3GPP protocol, two transmission modes are defined, namely, transmission mode 3 (mode 3) and transmission mode 4 (mode 4). The transmission resource of the terminal device using the transmission mode 3 is allocated by the base station, and the terminal device performs data transmission on the side line according to the resource allocated by the base station; the base station may allocate the resource for the single transmission to the terminal device, or may be the terminal. The device allocates resources that are semi-statically transmitted. If the terminal device using the transmission mode 4 has the capability of listening, the data is transmitted by means of sensing and reservation. If the listening capability is not available, the transmission resource is randomly selected in the resource pool. The terminal device with the interception capability acquires the available resource set by means of interception in the resource pool, and the terminal device randomly selects one resource from the set for data transmission. Since the service in the car network system has periodic characteristics, the terminal device usually adopts a semi-static transmission mode, that is, after the terminal device selects one transmission resource, the terminal device continuously uses the resource in multiple transmission cycles, thereby reducing the resource weight. The probability of selection and resource conflicts. The terminal device carries the information for reserving the next transmission resource in the control information of the current transmission, so that the other terminal device can determine whether the resource is reserved and used by the terminal device by detecting the control information of the terminal device. Reduce the purpose of resource conflicts.

The terminal device can perform the method shown in FIG. 3, for example, when performing resource sensing. In each sidelink process (one carrier can include two processes), when a new data packet arrives near the time n, resource selection or resource reselection is required, and the terminal device is based on the front The listening result of the listening window of 1s (ie 1000ms) is selected in the time interval [n+T1, n+T2]ms, and the time period [n+T1, n+T2]ms is called the selection window. Wherein T1 and T2 can satisfy, for example, T1≤4, 20≤T2≤100. The first 1 s described later is the first 1 s of the pointer for the time n. The specific resource selection process is as follows. Here, the terminal device 20 listens to the resources of the terminal device 30 as an example for description:

(0) It is assumed that all resources in the selection window constitute a candidate resource set S_A, assuming that the number of resources in the initial candidate resource set S_A is A:

(1) If there is no listening result on a certain subframe in the listening window, and another reserved subframe that is distributed according to a certain transmission period with the subframe falls within the selection window, then the selected window The resources on another subframe are excluded from the candidate resource set S_A, and the resources on the subframe in which the transmission resource reserved by the terminal device 20 according to a certain transmission period is also excluded from the candidate resource. The source set is outside the S_A. The transmission period may be an element in a set of transmission periods, which may be, for example, {20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000} ms. For example, as shown in FIG. 3, if the terminal 20 has no listening result on the resource A in the listening window, and the resource on the next transmission period corresponding to the resource A is the resource A1 in the selection window, the terminal 20 will use the resource A1. Excluded from the candidate resource set S_A.

(2) If the terminal device 20 detects the physical sidelink control channel (PSCCH) sent by the terminal device 30 in the listening window of the first 1 s, and the physical side row shared channel corresponding to the PSCCH The measured value of the Reference Signal Received Power (RSRP) of the (Physical Sidelink Shared Channel, PSSCH) is higher than the PSSCH-RSRP threshold, and the detected PSCCH indicates that the terminal device 30 that sends the PSCCH reserves the subsequent The time-frequency resource required for transmission (for example, in FIG. 3, the time-frequency resource reserved by the terminal device 30 is a time-domain location corresponding to the resource B in the listening window, which is located after the resource B, 100 ms, 200 ms, 300 ms, ..., etc. The time-frequency resource B1), the terminal device 20 determines the time-frequency resource reserved by the terminal device 30 in the selection window, and the time-frequency resource selected by the user in the selection window for transmitting data (for example, in FIG. 3, The time-frequency resource reserved by the terminal device 20 is whether the time-frequency resource A1) located after the resource A corresponding to the resource A in the listening window overlaps (including all overlapping or partial overlapping). If there is an overlap, that is, a resource conflict occurs, the terminal device 20 excludes the time-frequency resource within the selection window from the candidate resource set S_A. At this time, it is assumed that the number of remaining resources in the candidate resource set S_A is equal to B.

It should be understood that if the terminal device 20 selects the time-frequency resource for transmitting data for itself within the selection window, and needs to transmit data on a plurality of the time-frequency resources distributed according to the time period T ₂₀ , then If the terminal device 30 reserves a plurality of the time-frequency resources distributed according to the time period T ₃₀ , and the time period T ₂₀ satisfies T ₂₀ ×M=T ₃₀ ×N, and M and N are positive integers, the terminal device 20 A plurality of the time-frequency resources distributed according to the time period T ₂₀ are excluded from the candidate resource set.

(3) If the number of remaining resources B in the candidate resource set S_A is less than A × 20%, the terminal device 20 may increase the PSSCH-RSRP threshold by 3 dB, and repeat steps (0) through (2) until B ≥ A × 20 %.

In the embodiment of the present application, the PSSCH-RSRP threshold that is finally obtained is the PSSCH-RSRP threshold corresponding to the carrier where the side-line process is located.

(4) The terminal device 20 receives the received information for the remaining B resources in the candidate resource set S_A. The measurement of the Received Signal Strength Indicator (RSSI), and sorting according to the measurement result from high to low, shifts the A×20% resources with the lowest signal strength into the candidate resource set S_B.

(5) The terminal device 20 selects a time-frequency resource for data transmission in the candidate resource set S_B with equal probability.

It should be understood that the time-frequency resource occupied by the data channel corresponding to a certain control channel is referred to as a time-frequency resource (or a resource block) for transmitting the data channel, and the candidate resource set in each selection window is included. There may be multiple time-frequency resources for transmitting the data channel. For example, resources A1 and B1 in FIG. 3 can be referred to as one time-frequency resource.

After the terminal device 20 selects the time-frequency resource for data transmission, the time-frequency resource is continuously used in each transmission cycle of the subsequent transmission process, and the time-frequency resource C_resel is used in total, wherein C_resel is a resource reselection counter ( Resource Reselection Counter), the value of C_resel is decremented by 1 every time data is transmitted. When the value of C_resel is reduced to 0, the terminal device 20 generates a random number between [0, 1] and maintains the probability of resources (Probability). The resource Keep, ProbResourceKeep parameter is compared. The parameter indicates the probability that the terminal device continues to use the resource. If the value of the random number is greater than the parameter, the terminal device 20 performs resource reselection. If the value of the random number is smaller than the parameter, the terminal Device 20 may continue to use the time-frequency resource for data transmission and simultaneously reset the value of C_resel.

In a car network system supporting multi-carrier transmission, whether the terminal device uses the transmission mode 3 or the transmission mode 4, the current data transmission may be performed using one or more of the candidate multiple carriers. A terminal device using transmission mode 4 may select one or more carriers among a plurality of candidate carriers for current data transmission, and a terminal device using transmission mode 3 may perform current according to one or more carriers selected by the base station. data transmission.

The terminal device can measure the congestion degree of the system, for example, the Channel Busy Ratio (CBR), and the base station can instruct the terminal device to report the measurement result to the base station, so that the base station configures the transmission parameter according to the CBR configured by the terminal device, for example, the terminal device allows. Modulation Coding Mode (MCS), the number of physical resource blocks (PBR), the number of retransmissions, and other transmission parameters. The CBR can be used for the terminal device to perform carrier selection in multiple carriers. For example, the terminal device can select the lowest carrier of the CBR for data transmission according to the CBR measurement result of multiple carriers.

The CBR reflects the channel occupancy in the past 100 ms. The lower the CBR, the table The lower the system resource occupancy rate, the more resources are available. The higher the CBR, the higher the system resource occupancy rate is, the more congested it is, and the more likely it is to cause transmission conflicts and interference. However, for some services with low latency requirements, for example, services with a delay of less than or equal to 10 ms, at this time, the terminal device may not satisfy the terminal device according to the carrier selected by the CBR of the multiple carriers in the past 100 ms. The delay requirement of the transmitted service, that is, within the delay requirement of the service (for example, 10 ms), the most suitable transmission resource may not be selected for transmission of the service.

Therefore, the embodiment of the present application proposes that, according to the delay T of the target service to be transmitted, the terminal device selects according to the channel occupancy ratio CBR of the multiple carriers in the subframe [nP, n-P+(T-1)]. The target carrier of the target service is transmitted, so that effective carrier selection can be realized under the condition that the delay requirement is met.

FIG. 4 is a schematic flowchart of a method for selecting a carrier in D2D communication according to an embodiment of the present application. The method shown in FIG. 4 can be performed by a terminal device, which can be, for example, the terminal device 20 or the terminal device 30 shown in FIG. 2. As shown in FIG. 4, the method for selecting a carrier in the D2D communication includes:

In 410, the terminal device acquires CBRs of a plurality of carriers within a subframe [n-P, n-P+(T-1)].

The T is the time delay of the target service to be transmitted, the subframe n is the time when the target service arrives, or the time at which the terminal device needs to perform carrier selection or resource selection, and P is a positive integer, for example, P=100 ms.

In 420, the terminal device performs the carrier selection on the multiple carriers according to the CBR of the multiple carriers to obtain a target carrier for transmitting the target service.

Therefore, the terminal device selects a target carrier for transmitting the target service according to a channel occupancy ratio CBR of the plurality of carriers in the subframe [nP, n-P+(T-1)], wherein the target service to be transmitted is considered. The delay T is such that effective carrier selection can be achieved under the condition that the delay requirement is met.

For example, the terminal device may acquire a channel occupancy ratio CBR of multiple carriers in a subframe [nP, n-P+(T-1)], and select CBR among the multiple carriers according to CBR of the multiple carriers. The smallest carrier acts as the target carrier for transmitting the target service.

Optionally, in 420, the terminal device performs the carrier selection in the multiple carriers according to the CBR of the multiple carriers, where: the terminal device separately performs CBR according to the multiple carriers. Filtering the CBRs of the multiple carriers to obtain CBRs of the filtered multiple carriers; and selecting the target carriers among the multiple carriers according to the filtered CBRs of the multiple carriers.

Specifically, the terminal device acquires CBRs of the multiple carriers in the subframe [nP, n-P+(T-1)], and performs filtering processing on the CBRs of the multiple carriers to obtain the filtered processing. CBR of the carrier. Then, the target carrier is selected among the plurality of carriers according to the filtered CBR of the multiple carriers.

Since the CBR of each carrier may change rapidly with the change of the location of the terminal device, or change with time, the CBR of each carrier is filtered by filtering the measured values of the CBR of each carrier. It tends to be stable, which reduces the frequency of carrier selection and ensures the stability of the system.

Optionally, performing filtering processing on the CBRs of the multiple carriers includes: performing smoothing filtering on CBRs of the multiple carriers.

The manner of smoothing filtering is not limited in the embodiment of the present application.

For example, the smoothing filtering method may be CBR_new=a×CBR_old+(1-a)×CBR_current.

CBR_new is the CBR of each carrier after filtering, CBR_current is the CBR of each carrier before filtering, CBR_old is the CBR of each carrier after the last filtering, a is the filter coefficient and 0≤a≤1.

It can be seen that since the measured CBR is filtered by using an appropriate filtering method, frequent carrier selection caused by CBR variation is avoided.

FIG. 5 is a schematic flowchart of a method for selecting a carrier in D2D communication according to an embodiment of the present application. The method shown in FIG. 5 can be performed by a terminal device, which can be, for example, the terminal device 20 or the terminal device 30 shown in FIG. 2. As shown in FIG. 5, the method for selecting a carrier in the D2D communication includes:

In 510, the physical layer of the terminal device performs resource sensing on multiple carriers in a time interval [n+T1, n+T2], where n is the time at which the target service to be transmitted arrives, or determines that the terminal device needs to perform When the carrier is selected or the resource is selected, 0 ≤ T1 < T2.

Optionally, the T2 is less than or equal to the delay of the target service.

In this way, since the terminal device considers the delay of the target service, it is possible to implement effective carrier selection under the condition that the delay requirement is satisfied.

In 520, the physical layer of the terminal device determines, according to the result of the resource interception, a set of available resources on the multiple carriers that can be used to transmit the target service, and multiple physical side links corresponding to the multiple carriers. The shared channel reference signal receives the power PSSCH-RSRP threshold.

The PSSCH-RSRP of the resource in the available resource set on each carrier is less than or equal to the PSSCH-RSRP threshold corresponding to each carrier.

In 530, the terminal device performs the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain a target carrier for transmitting the target service.

Specifically, the physical layer of the terminal device performs resource sensing on the candidate multiple carriers in the time interval [n+T1, n+T2], and determines, according to the interception result, that the multiple carriers are available for transmitting the target. A collection of available resources for a business. Where n is the time when the target service arrives, or n is the time at which the first terminal device determines that carrier selection or resource selection is required. For example, if the target service arrives before time n, then the physicality of the first terminal device The layer may receive the request sent by its upper layer at time n, so that the physical layer of the first terminal device decides at time n that carrier selection or resource selection needs to be performed within the time interval [n+T1, n+T2], so as to The target service looks for transmission resources.

The terminal device determines a process of a set of available resources on each carrier, for example, reference may be made to steps (0) through (4) in the description in FIG. For example, assuming that the first carrier is included in the multiple carriers, the terminal device performs resource sensing on the first carrier within a time interval [n+T1, n+T2], and excludes the PSSCH according to the interception result. - the resource whose RSRP measurement value is higher than the PSSCH-RSRP threshold and occupied and reserved by other terminal devices, and further selects the resource with the lowest RSSI measurement value which accounts for 20% of the total number of resources in the selection window among the remaining resources, wherein is selected The 20% of the resources constitute the set of available resources on the first carrier. The set of available resources can be understood as the candidate resource set S_B obtained after completing step (4). Moreover, the PSSCH-RSRP threshold corresponding to the first carrier is the PSSCH-RSRP threshold used when the step (2) or (3) finally satisfies B ≥ A × 20%.

It should be understood that the method for acquiring the available resource set on the carrier other than the first carrier, and the method for obtaining the PSSCH-RSRP threshold corresponding to the other carrier may refer to the description of the first carrier. For the sake of brevity, it will not be repeated here.

Finally, the terminal device may perform carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, thereby acquiring a target carrier for transmitting the target service. The terminal device may select an appropriate time-frequency resource for transmitting the target service in the available resource set on the target carrier. In the embodiment of the present application, the terminal device determines, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, the target carrier used for transmitting the target service, which may be implemented in the following two manners.

Mode 1

Optionally, the terminal device determines, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a target carrier for transmitting the target service, where the physical layer of the terminal device is configured according to multiple PSSCHs corresponding to the multiple carriers. An RSRP threshold, in which the carrier with the smallest PSSCH-RSRP threshold is selected as the target carrier.

Further, optionally, the method further includes: the physical layer of the terminal device reports the set of available resources on the target carrier to a higher layer of the terminal device, and/or the physical layer of the terminal device uses the target carrier The index is reported to the upper layer of the terminal device; the upper layer of the terminal device selects a resource for transmitting the target service in the available resource set on the target carrier.

Mode 2

Optionally, the terminal device determines, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a target carrier for transmitting the target service, where the physical layer of the terminal device reports the multiple to the high layer of the terminal device. A plurality of PSSCH-RSRP thresholds corresponding to the carrier; the higher layer of the terminal device selects, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a carrier with the smallest PSSCH-RSRP threshold as the target carrier.

Further, the method further includes: the physical layer of the terminal device reports the available resource set on the multiple carriers to the upper layer of the terminal device; the upper layer of the terminal device is in the available resource set on the target carrier , select the resource used to transfer the target service.

It can be seen that, in the mode 1, the physical layer of the terminal device selects a carrier with the smallest PSSCH-RSRP threshold as the target carrier among the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, and uses the target carrier. The resource set and/or the index of the target carrier is reported to its upper layer. The upper layer of the terminal device selects a resource for transmitting the target service in a set of available resources on the target carrier.

In the mode 2, after the physical layer of the terminal device determines the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, the multiple PSSCH-RSRP thresholds may be directly reported to the upper layer of the terminal device, and the PSSCH is selected by the upper layer. - The carrier with the smallest RSRP threshold is used as the target carrier. And the physical layer of the terminal device may also report the set of available resources on the determined plurality of carriers at the same time, so that the upper layer of the terminal device selects, in the set of available resources on the target carrier, the target service. H.

Therefore, in the embodiment of the present application, the terminal device may obtain multiple PSSCH-RSRP thresholds corresponding to the multiple carriers in the process of determining the available resource set on the multiple carriers, and according to the multiple corresponding to the multiple carriers, The PSSCH-RSRP threshold effectively implements carrier selection, thereby enabling the branch A terminal device in a system with multi-carrier transmission can acquire resources in the selected carrier for data transmission.

It should be understood that, in the various embodiments of the present application, the size of the sequence numbers of the foregoing processes does not mean the order of execution sequence, and the order of execution of each process should be determined by its function and internal logic, and should not be applied to the embodiment of the present application. The implementation process constitutes any limitation.

The method for carrier selection in D2D communication according to the embodiment of the present application is described in detail above. The device according to the embodiment of the present application will be described below with reference to FIG. 6 to FIG. 9. The technical features described in the method embodiment are applicable to the following device implementation. example.

FIG. 6 is a schematic block diagram of a terminal device 600 according to an embodiment of the present application. As shown in FIG. 6, the terminal device 600 includes an obtaining module 610 and a carrier selecting module 620620. among them:

The obtaining module 610 is configured to obtain a channel occupancy ratio CBR of the multiple carriers in the subframe [nP, n-P+(T-1)], where T is a delay of the target service to be transmitted, and the subframe n is Determining when the target service arrives, or determining, for the terminal device, a time at which carrier selection or resource selection is required;

The carrier selection module 620 is configured to perform the carrier selection in the multiple carriers according to the CBR of the multiple carriers acquired by the acquiring module 610 to obtain a target carrier for transmitting the target service.

Therefore, the terminal device selects a target for transmitting the target service according to the delay T of the target service to be transmitted according to the channel occupancy ratio CBR of the plurality of carriers in the subframe [nP, n-P+(T-1)]. Carrier, so that effective carrier selection can be achieved while satisfying the delay requirements.

Optionally, the carrier selection module 620 is specifically configured to: perform filtering processing on the CBRs of the multiple carriers, respectively, to obtain CBRs of the filtered multiple carriers; according to the filtered multiple carriers CBR, selecting the target carrier among the plurality of carriers.

Optionally, the carrier selection module 620 is specifically configured to perform smoothing filtering on the CBRs of the multiple carriers.

Optionally, the CBR of each of the plurality of carriers after the smoothing is performed is: CBR_new=a×CBR_old+(1-a)×CBR_current, where CBR_new is the CBR of each carrier after filtering. CBR_current is the CBR of each carrier before filtering, CBR_old is the CBR of each carrier after the last filtering, a is a filter coefficient and 0≤a≤1.

Optionally, the carrier selection module 620 is specifically configured to: select, according to the CBR of the multiple carriers, a carrier with a minimum CBR as the target carrier among the multiple carriers.

It should be understood that the terminal device 600 can perform the corresponding operations of the method 400 performed by the terminal device in the foregoing method embodiment, and details are not described herein for brevity.

FIG. 7 is a schematic block diagram of a terminal device 700 according to an embodiment of the present application. As shown in FIG. 7, the terminal device 700 includes a physical layer module 710 and a high layer module 720. among them:

The physical layer module 710 is configured to perform resource sensing on multiple carriers in a time interval [n+T1, n+T2], where n is the time when the target service to be transmitted arrives, or the terminal device determines the need When the carrier selection or resource selection is performed, 0≤T1<T2;

The physical layer module 710 is further configured to: determine, according to a result of the resource interception, an available resource set that is available to transmit the target service on the multiple carriers, and multiple physical entities corresponding to the multiple carriers a side channel shared channel reference signal receiving power PSSCH-RSRP threshold, wherein a PSSCH-RSRP of a resource in a set of available resources on each carrier is less than or equal to a PSSCH-RSRP threshold corresponding to each carrier;

The physical layer module 710 is further configured to perform the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain a target carrier for transmitting the target service; or

The high-level module 720 is further configured to perform the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain a target carrier for transmitting the target service.

Therefore, in determining a set of available resources on the multiple carriers, the terminal device may obtain multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, and effectively use multiple PSSCH-RSRP thresholds corresponding to the multiple carriers. Carrier selection is implemented such that a terminal device in a system supporting multi-carrier transmission can acquire resources in the selected carrier for data transmission.

Optionally, the physical layer module 710 is specifically configured to: select, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a carrier with a minimum PSSCH-RSRP threshold as the target carrier.

Optionally, the physical layer module 710 is further configured to report the available resource set on the target carrier to the high-level module 720, and/or the physical layer module 710 reports the index of the target carrier. The high-level module 720 is further configured to: select, in the set of available resources on the target carrier, a resource used to transmit the target service.

Optionally, the physical layer module 710 is further configured to report, by the high-level module 720, a plurality of PSSCH-RSRP thresholds corresponding to the multiple carriers, where the high-level module 720 is specifically configured to: according to the multiple carriers Corresponding multiple PSSCH-RSRP thresholds, selecting among the multiple carriers The carrier with the smallest PSSCH-RSRP threshold is used as the target carrier.

Optionally, the physical layer module 710 is further configured to: report the available resource set on the multiple carriers to the high-level module 720; the high-level module 720 is further configured to: use resources on the target carrier In the collection, a resource for transmitting the target service is selected.

Optionally, T2 is less than or equal to a delay of the target service.

It should be understood that the terminal device 700 can perform the corresponding operations of the method 500 performed by the terminal device in the foregoing method embodiment. For brevity, no further details are provided herein.

FIG. 8 is a schematic structural diagram of a terminal device 800 according to an embodiment of the present application. As shown in FIG. 8, the terminal device includes a processor 810, a transceiver 820, and a memory 830, wherein the processor 810, the transceiver 820, and the memory 830 communicate with each other through an internal connection path. The memory 830 is for storing instructions, and the processor 810 is configured to execute instructions stored by the memory 830 to control the transceiver 820 to receive signals or send signals.

Optionally, the processor 810 can call the program code stored in the memory 830 to perform the corresponding operations of the method 400 performed by the terminal device in the method embodiment. For brevity, no further details are provided herein.

Optionally, the processor 810 can call the program code stored in the memory 830 to perform the corresponding operations of the method 500 performed by the terminal device in the method embodiment. For brevity, no further details are provided herein.

It should be understood that the processor of the embodiment of the present application may be an integrated circuit chip with signal processing capability. In the implementation process, each step of the foregoing method embodiment may be completed by an integrated logic circuit of hardware in a processor or an instruction in a form of software. The processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like. Programming logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the above The steps of the law.

It is to be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (Erasable PROM, EPROM), or an electric Erase programmable read only memory (EEPROM) or flash memory. The volatile memory can be a Random Access Memory (RAM) that acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (Synchronous DRAM). SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synchronous Connection Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (DR RAM). It should be noted that the memories of the systems and methods described herein are intended to comprise, without being limited to, these and any other suitable types of memory.

FIG. 9 is a schematic structural diagram of a system chip according to an embodiment of the present application. The system chip 900 of FIG. 9 includes an input interface 901, an output interface 902, at least one processor 903, and a memory 904. The input interface 901, the output interface 902, the processor 903, and the memory 904 are interconnected by an internal connection path. . The processor 903 is configured to execute code in the memory 904.

Alternatively, when the code is executed, the processor 903 can implement the method 400 performed by the terminal device in the method embodiment. For the sake of brevity, it will not be repeated here.

Alternatively, when the code is executed, the processor 903 can implement the method 500 performed by the terminal device in the method embodiment. For the sake of brevity, it will not be repeated here.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

It will be apparent to those skilled in the art that the above description is convenient and concise for the description. For the specific working process of the system, the device and the unit, reference may be made to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or may be Integrate into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one monitoring unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present application, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The foregoing is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application. It should be covered by the scope of protection of this application. Therefore, the scope of protection of the present application should be determined by the scope of the claims.

Claims

A method for device selection in device D2D communication, characterized in that the method comprises:

The terminal device acquires a channel occupancy ratio CBR of the plurality of carriers in the subframe [nP, n-P+(T-1)], where T is a delay of the target service to be transmitted, P is a positive integer, and subframe n is a time when the target service arrives, or a time at which the terminal device needs to perform carrier selection or resource selection;

The terminal device performs the carrier selection in the multiple carriers according to the CBR of the multiple carriers to obtain a target carrier for transmitting the target service.
The method according to claim 1, wherein the terminal device performs the carrier selection in the multiple carriers according to the CBR of the multiple carriers, including:

The terminal device performs filtering processing on the CBRs of the multiple carriers to obtain a filtered CBR of the multiple carriers;

Selecting the target carrier among the plurality of carriers according to the filtered CBR of the plurality of carriers.
The method according to claim 2, wherein the filtering processing the CBRs of the plurality of carriers separately comprises:

Smoothing the CBR of the plurality of carriers separately.
The method according to claim 3, wherein the CBR of each of the plurality of carriers after the smoothing is performed is:

CBR_new=a×CBR_old+(1-a)×CBR_current,

The CBR_new is the CBR of each carrier after the filtering, and the CBR_current is the CBR of each carrier before the filtering, and the CBR_old is the CBR of each carrier after the last filtering, a is a filter coefficient and 0≤a≤ 1.
The method according to any one of claims 1 to 4, wherein the terminal device performs the carrier selection in the multiple carriers according to the CBR of the multiple carriers, including:

The terminal device selects, as the target carrier, a carrier with a minimum CBR among the multiple carriers according to the CBR of the multiple carriers.
A method for device selection in device D2D communication, characterized in that the method comprises:

The physical layer of the terminal device performs resource detection on multiple carriers within the time interval [n+T1, n+T2] Listening, n is the time when the target service to be transmitted arrives, or the time at which the terminal device needs to perform carrier selection or resource selection, 0 ≤ T1 < T2;

Determining, by the physical layer of the terminal device, a set of available resources on the multiple carriers that are used to transmit the target service, and multiple physical side line chains corresponding to the multiple carriers, according to the result of the resource interception The channel shared channel reference signal receives the power PSSCH-RSRP threshold, where the PSSCH-RSRP of the resource in the available resource set on each carrier is less than or equal to the PSSCH-RSRP threshold corresponding to each carrier;

The terminal device performs the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain a target carrier for transmitting the target service.
The method according to claim 6, wherein the terminal device determines, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a target carrier for transmitting the target service, including:

The physical layer of the terminal device selects, as the target carrier, a carrier with the smallest PSSCH-RSRP threshold among the multiple carriers according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.
The method of claim 7, wherein the method further comprises:

The physical layer of the terminal device reports the set of available resources on the target carrier to the upper layer of the terminal device, and/or the physical layer of the terminal device reports the index of the target carrier to the terminal device. High level

The higher layer of the terminal device selects a resource for transmitting the target service in a set of available resources on the target carrier.
The method according to claim 6, wherein the terminal device determines, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a target carrier for transmitting the target service, including:

The physical layer of the terminal device reports multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to the upper layer of the terminal device;

The higher layer of the terminal device selects, as the target carrier, a carrier with the smallest PSSCH-RSRP threshold among the multiple carriers according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.
The method of claim 9 wherein the method further comprises:

The physical layer of the terminal device reports the available resource set on the multiple carriers to the upper layer of the terminal device;

The higher layer of the terminal device selects a resource for transmitting the target service in a set of available resources on the target carrier.
The method according to any one of claims 6 to 10, characterized in that T2 is less than or equal to the delay of the target service.
A terminal device, the terminal device includes:

An acquiring module, configured to acquire a channel occupancy ratio CBR of the multiple carriers in the subframe [nP, n-P+(T-1)], where T is a delay of the target service to be transmitted, and subframe n is the The moment when the target service arrives, or the time at which the terminal device needs to perform carrier selection or resource selection;

And a carrier selection module, configured to perform the carrier selection in the multiple carriers according to the CBR of the multiple carriers acquired by the acquiring module, to obtain a target carrier used for transmitting the target service.
The terminal device according to claim 12, wherein the carrier selection module is specifically configured to:

Performing filtering processing on the CBRs of the multiple carriers to obtain CBRs of the filtered multiple carriers;

Selecting the target carrier among the plurality of carriers according to the filtered CBR of the plurality of carriers.
The terminal device according to claim 13, wherein the carrier selection module is specifically configured to:

Smoothing the CBR of the plurality of carriers.
The terminal device according to claim 14, wherein the CBR of each of the plurality of carriers after the smoothing is performed is:

CBR_new=a×CBR_old+(1-a)×CBR_current,

The CBR_new is the CBR of each carrier after the filtering, and the CBR_current is the CBR of each carrier before the filtering, and the CBR_old is the CBR of each carrier after the last filtering, a is a filter coefficient and 0≤a≤ 1.
The terminal device according to any one of claims 12 to 15, wherein the carrier selection module is specifically configured to:

And selecting, according to the CBR of the multiple carriers, a carrier with a smallest CBR among the multiple carriers as the target carrier.
A terminal device, wherein the terminal device includes a physical layer module and a high layer Module, where:

The physical layer module is configured to perform resource sensing on multiple carriers in a time interval [n+T1, n+T2], where n is the time when the target service to be transmitted arrives, or it is determined that the terminal device needs to perform The time of carrier selection or resource selection;

The physical layer module is further configured to: determine, according to a result of the resource interception, a set of available resources on the multiple carriers that are used to transmit the target service, and multiple physical sides corresponding to the multiple carriers a line-sharing channel reference signal receiving power PSSCH-RSRP threshold, wherein a PSSCH-RSRP of a resource in a set of available resources on each carrier is less than or equal to a PSSCH-RSRP threshold corresponding to each carrier;

The physical layer module is further configured to perform the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain a target carrier for transmitting the target service; or

The high-level module is further configured to perform the carrier selection according to multiple PSSCH-RSRP thresholds corresponding to the multiple carriers to obtain a target carrier for transmitting the target service.
The terminal device according to claim 17, wherein the physical layer module is specifically configured to:

And selecting, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a carrier with the smallest PSSCH-RSRP threshold as the target carrier among the multiple carriers.
The terminal device according to claim 18, wherein the physical layer module is further configured to:

Evaluating the set of available resources on the target carrier to the high-level module, and/or the physical layer module reporting the index of the target carrier to the high-level module;

The high-level module is further configured to select, in the set of available resources on the target carrier, a resource for transmitting the target service.
The terminal device according to claim 17, wherein the physical layer module is further configured to:

And reporting, to the high-level module, multiple PSSCH-RSRP thresholds corresponding to the multiple carriers;

The high-level module is specifically configured to select, according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers, a carrier with a minimum PSSCH-RSRP threshold as the target carrier.
The terminal device according to claim 20, wherein the physical layer module is further configured to:

Reporting, to the high-level module, a set of available resources on the multiple carriers;

The high-level module is further configured to select, in the set of available resources on the target carrier, a resource for transmitting the target service.
The terminal device according to any one of claims 17 to 21, wherein T2 is less than or equal to a delay of the target service.