CN110741708B

CN110741708B - Method for selecting carrier in D2D communication and terminal equipment

Info

Publication number: CN110741708B
Application number: CN201780091672.XA
Authority: CN
Inventors: 唐海
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2017-11-03
Filing date: 2017-11-03
Publication date: 2021-01-12
Anticipated expiration: 2037-11-03
Also published as: CN110741708A; WO2019084925A1

Abstract

The application discloses a method for selecting carriers in D2D communication and terminal equipment, wherein the method comprises the following steps: the method comprises the following steps: the method comprises the steps that terminal equipment obtains channel occupation ratios CBR of a plurality of carriers in a subframe [ n-P, n-P + (T-1) ], wherein T is time delay of a target service to be transmitted, and subframe n is the time when the target service arrives, or the time when carrier selection or resource selection is needed is determined for the terminal equipment; and the terminal equipment selects the carrier in the plurality of carriers according to the CBRs of the plurality of carriers so as to acquire a target carrier for transmitting the target service. Therefore, the terminal equipment can realize effective carrier selection under the condition of meeting the time delay requirement.

Description

Method for selecting carrier in D2D communication and terminal equipment

Technical Field

The embodiment of the present application relates to the field of wireless communication, and more particularly, to a method and a terminal Device for carrier selection in Device-to-Device (D2D) communication.

Background

A Vehicle networking or Vehicle-to-Device (V2X) communication system is a Sidelink (SL) transmission technology based on Device-to-Device (D2D) communication, and is different from a method of receiving or sending data through a base station in a conventional Long Term Evolution (LTE) system, and the Vehicle networking system adopts a terminal-to-terminal direct communication method, so that the Vehicle networking or Vehicle-to-Device (V2X) communication system has higher spectral efficiency and lower transmission delay.

In a vehicle networking system supporting multi-carrier transmission, a terminal device may use one or more carriers of a candidate plurality of carriers for current data transmission. Therefore, how to select the carrier by the terminal device or the base station becomes an urgent problem to be solved.

Disclosure of Invention

The embodiment of the application provides a method for selecting carriers in D2D communication and terminal equipment, wherein the terminal equipment can effectively select the carriers and simultaneously meet the requirement of time delay.

In a first aspect, a method for carrier selection in D2D communication is provided, including: the method comprises the steps that terminal equipment obtains channel occupation ratios CBR of a plurality of carriers in a subframe [ n-P, n-P + (T-1) ], wherein T is time delay of a target service to be transmitted, P is a positive integer, and subframe n is the time when the target service arrives, or the time when carrier selection or resource selection is needed is determined for the terminal equipment; and the terminal equipment selects the carrier in the plurality of carriers according to the CBRs of the plurality of carriers so as to acquire a target carrier for transmitting the target service.

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

Optionally, the P may be a period for carrier selection or resource selection. For example, if the subframe n is a time when the terminal device determines that carrier selection or resource selection is required, then n-P may be considered as a time when the terminal device determines that carrier selection or resource selection is required last time, and P is, for example, 100 ms.

In a possible implementation manner, the selecting, by the terminal device, the carrier in the multiple carriers according to the CBRs of the multiple carriers includes: the terminal equipment respectively carries out filtering processing on the CBRs of the multiple carriers to obtain the filtered CBRs of the multiple carriers; selecting the target carrier from the plurality of carriers according to the filtered CBRs of the plurality of carriers.

In a possible implementation manner, the performing filter processing on the CBRs of the multiple carriers respectively includes: and performing smooth filtering on the CBRs of the multiple carriers respectively.

In one possible implementation manner, the CBR of each carrier of the multiple carriers after the smoothing filtering is: CBR _ new ═ a × CBR _ old + (1-a) × CBR _ current,

the CBR _ new is the CBR of each carrier after filtering, the CBR _ current is the CBR of each carrier before filtering, the CBR _ old is the CBR of each carrier after last filtering, and a is a filter coefficient and is greater than or equal to 0 and less than or equal to 1.

In a possible implementation manner, the selecting, by the terminal device, the carrier in the multiple carriers according to the CBRs of the multiple carriers includes: and the terminal equipment selects the carrier with the minimum CBR from the plurality of carriers as the target carrier according to the CBRs of the plurality of carriers.

In a second aspect, a method for carrier selection in D2D communication is provided, including: a physical layer of terminal equipment carries out resource interception on a plurality of carriers within a time interval [ n + T1, n + T2], wherein n is the time when a target service to be transmitted arrives or the time when the terminal equipment determines that carrier selection or resource selection needs to be carried out, and T1 is more than or equal to 0 and is less than T2; the physical layer of the terminal equipment determines an available resource set which can be used for transmitting the target service on the multiple carriers and multiple physical sidelink shared channel reference signal received power PSSCH-RSRP thresholds corresponding to the multiple carriers according to the result of the resource monitoring, wherein 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; and the terminal equipment selects the carrier according to a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers so as to acquire a target carrier for transmitting the target service.

Therefore, in the embodiment of the present application, in the process of determining an available resource set on multiple carriers, the terminal device may obtain multiple psch-RSRP thresholds corresponding to the multiple carriers, and effectively implement carrier selection according to the multiple psch-RSRP thresholds corresponding to the multiple carriers, so that the terminal device in the system supporting multi-carrier transmission may obtain resources in the selected carriers to perform data transmission.

In a possible implementation manner, the determining, by the terminal device, a target carrier for transmitting the target service according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers includes: and the physical layer of the terminal equipment selects a carrier with the minimum PSSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

In one possible implementation, the method further includes: the physical layer of the terminal equipment reports the available resource set on the target carrier to the high layer of the terminal equipment, and/or the physical layer of the terminal equipment reports the index of the target carrier to the high layer of the terminal equipment; and the high layer of the terminal equipment selects resources for transmitting the target service from the available resource set on the target carrier.

In a possible implementation manner, the determining, by the terminal device, a target carrier for transmitting the target service according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers includes: the physical layer of the terminal equipment reports a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers to the high layer of the terminal equipment; and the high layer of the terminal equipment selects a carrier with the minimum PSSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

In one possible implementation, the method further includes: the physical layer of the terminal equipment reports the available resource sets on the multiple carriers to the high layer of the terminal equipment; and the high layer of the terminal equipment selects resources for transmitting the target service from the available resource set on the target carrier.

In one possible implementation, T2 is less than or equal to the latency of the target traffic.

In a third aspect, a terminal device is provided, where the terminal device may perform the operations of the terminal device in the first aspect or any optional implementation manner of the first aspect. In particular, the terminal device may comprise a module unit for performing the operations of the terminal device in the first aspect or any possible implementation manner of the first aspect.

In a fourth aspect, a terminal device is provided, which may perform the operations of the terminal device in the second aspect or any optional implementation manner of the second aspect. In particular, the terminal device may comprise a module unit for performing the operations of the terminal device in the second aspect or any possible implementation manner of the second aspect.

In a fifth aspect, a terminal device is provided, which includes: a processor, a transceiver, and a memory. Wherein the processor, the transceiver and the memory are in communication with each other via an internal connection path. The memory is configured to store instructions and the processor is configured to execute the instructions stored by the memory. When the processor executes the instructions stored in the memory, the execution causes the terminal device to perform the method of the first aspect or any possible implementation manner 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, which includes: a processor, a transceiver, and a memory. Wherein the processor, the transceiver and the memory are in communication with each other via an internal connection path. The memory is configured to store instructions and the processor is configured to execute the instructions stored by the memory. When the processor executes the instructions stored in the memory, the execution causes the terminal device to execute the method of the second aspect or any possible implementation manner of the second aspect, or the execution causes the terminal device to implement the terminal device provided by the fourth aspect.

In a seventh aspect, a computer-readable storage medium is provided, where the computer-readable storage medium stores a program, where the program enables a terminal device to execute the method for carrier selection in D2D communication according to the first aspect and any one of its various implementations.

In an eighth aspect, a computer-readable storage medium is provided, which stores a program that causes a terminal device to execute the method for carrier selection in D2D communication of the second aspect and any of its various implementations.

In a ninth aspect, a system chip is provided, which comprises an input interface, an output interface, a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and when the instructions are executed, the processor may implement the method of the first aspect or any possible implementation manner of the first aspect.

In a tenth aspect, a system chip is provided, which comprises an input interface, an output interface, a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and when the instructions are executed, the processor may implement the method of the second aspect or any possible implementation manner of the second aspect.

In an eleventh aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the first aspect or any possible implementation manner of the first aspect.

In a twelfth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the second aspect described above or any possible implementation of the second aspect.

Drawings

Fig. 1 is a schematic architecture diagram of an application scenario according to an embodiment of the present application.

Fig. 2 is a schematic architecture diagram of another application scenario of an embodiment of the present application.

Fig. 3 is a schematic diagram of resource sensing and selection.

Fig. 4 is a schematic flow chart of a method for carrier selection according to an embodiment of the present application.

Fig. 5 is a schematic flow chart of a method of 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 configuration diagram of a communication apparatus 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 Description

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 may be applied to various communication systems, for example: a Global System for Mobile communications (GSM) System, a Code Division Multiple Access (CDMA) System, a Wideband Code Division Multiple Access (WCDMA) System, a Long Term Evolution (Long Term Evolution) System, an LTE (Frequency Division Duplex) System, an LTE Time Division Duplex (FDD) System, a Time Division Duplex (TDD), a Universal Mobile Telecommunications System (UMTS), and a future 5G Communication System.

Various embodiments are described herein in connection with a terminal device. A terminal device may also refer to a User Equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a User terminal, a wireless communication device, a User agent, or a User Equipment. An 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), a handheld device with Wireless communication capability, a computing device or other processing device connected to a Wireless modem, a vehicle mounted device, a wearable device, a terminal device in a future 5G Network or a terminal device in a future evolved Public Land Mobile Network (PLMN) Network, etc.

Various embodiments are described herein in connection with a network device. The network device may be a device for communicating with the terminal device, and for example, may be a Base Transceiver Station (BTS) in a GSM system or a CDMA system, a Base Station (NodeB, NB) in a WCDMA system, an evolved Node B (eNB, or eNodeB) in an LTE system, or may be a relay Station, an access point, a vehicle-mounted device, a wearable device, and a network-side device in a future 5G network or a network-side device in a future evolved PLMN network.

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

Specifically, the terminal device 20 and the terminal device 30 can communicate in the D2D communication mode, and when the D2D communication is performed, the terminal device 20 and the terminal device 30 directly communicate via a D2D link, i.e., a Sidelink (SL). For example, as shown in fig. 1 or fig. 2, terminal device 20 and terminal device 30 communicate directly via a sidelink. In fig. 1, terminal device 20 and terminal device 30 communicate via a sidelink, the transmission resources of which are allocated by the network device; in fig. 2, terminal device 20 and terminal device 30 communicate via a sidelink, and their transmission resources are selected by the terminal device autonomously without the need for the network device to allocate transmission resources.

D2D communication may refer to Vehicle-to-Vehicle (V2V) communication or Vehicle-to-other device (V2X) communication. In V2X communication, X may refer to any device with wireless receiving and transmitting capability, such as but not limited to a slow moving wireless device, a fast moving vehicle-mounted device, or a network control node with wireless transmitting and receiving capability. It should be understood that the embodiment of the present invention is mainly applied to the scenario of V2X communication, but may also be applied to any other D2D communication scenario, and the embodiment of the present invention is not limited in this respect.

In the car networking system, there may be two types of terminal devices, namely, a terminal device with a listening capability such as a Vehicle User Equipment (VUE) or a Pedestrian hand-held terminal (PUE), and a terminal device without a listening capability such as a PUE. VUEs have higher processing capability and are generally powered by a storage battery in a vehicle, while PUE processing capability is lower, and reduction of power consumption is also a main factor to be considered by PUEs, so in the existing vehicle networking system, VUEs are considered to have complete receiving capability and listening capability; while PUEs are considered to have partial or no receiving and listening capabilities. If the PUE has partial interception capability, the resources can be selected by adopting an interception method similar to that of the VUE, and available resources can be selected on the intercepted resources; and if the PUE does not have the interception capability, the PUE randomly selects transmission resources in the resource pool.

In Release-14 of the 3GPP protocol, two transmission modes, i.e., transmission mode 3(mode 3) and transmission mode 4(mode 4), are defined. The transmission resource of the terminal equipment using the transmission mode 3 is allocated by the base station, and the terminal equipment transmits data on a sidelink according to the resource allocated by the base station; the base station may allocate resources for single transmission to the terminal device, or may allocate resources for semi-static transmission to the terminal device. If the terminal equipment using the transmission mode 4 has the interception capability, adopting an interception (sending) and reservation (reservation) mode to transmit data, and if the terminal equipment does not have the interception capability, randomly selecting transmission resources in the resource pool. The terminal equipment with the interception capability acquires an available resource set in a resource pool in an interception mode, and the terminal equipment randomly selects one resource from the set for data transmission. Because the service in the car networking system has a periodic characteristic, the terminal device usually adopts a semi-static transmission mode, that is, after the terminal device selects one transmission resource, the resource is continuously used in a plurality of transmission cycles, so that the probability of resource reselection and resource conflict is reduced. The terminal device can carry the information of the reserved secondary transmission resource in the control information transmitted this time, so that other terminal devices can judge whether the resource is reserved and used by the terminal device by detecting the control information of the terminal device, and the purpose of reducing resource conflict is achieved.

The terminal device may perform the method shown in fig. 3, for example, when performing resource sensing. Wherein, in each sidelink process (sidelink process) (one carrier may include two processes), when a new data packet arrives near time n, resource selection or resource reselection is required, the terminal device performs resource selection in time interval [ n + T1, n + T2] ms according to the listening result of the previous 1s (i.e. 1000ms) listening window, the time period of [ n + T1, n + T2] ms is called as the selection window, where T1 and T2 may satisfy T1 ≦ 4, and T2 ≦ 100, for example. The first 1s mentioned later all refer to the first 1s for the time n. The specific resource selection process is as follows, and here, the resource of the terminal device 30 intercepted by the terminal device 20 is described as an example:

(0) assuming 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 subframe within the listening window, and another reserved subframe distributed with the subframe according to a certain transmission period falls within the selection window, the resource on the other subframe within the selection window is excluded from the candidate resource set S _ a, and the resource on the subframe where the transmission resource reserved by the terminal device 20 according to a certain transmission period is also excluded from the candidate resource set S _ a. The transmission period may be an element of 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 resource a within the listening window and the resource on the next transmission cycle corresponding to this resource a is resource a1 within the selection window, the terminal 20 excludes resource a1 from the candidate resource set S _ a.

(2) If terminal device 20 detects, within the listening window of the first 1s, that a Physical Sidelink Control Channel (PSCCH) transmitted by terminal device 30 is detected, and a measured value of Reference Signal Received Power (RSRP) of a Physical Sidelink Shared Channel (PSCCH) corresponding to the PSCCH is higher than a PSCCH-RSRP threshold, and the detected PSCCH indicates that terminal device 30 transmitting the PSCCH reserves resources required for subsequent transmission (e.g., in fig. 3, terminal device 30 reserves time-frequency resources B1 located at a position 100ms, 200ms, 300ms, etc. after resource B corresponding to resource B within the listening window), terminal device 20 determines that the reserved resources within the selection window by terminal device 30 are within a time-frequency resource range selected for transmitting data within the selection window (e.g., in fig. 3, the time-frequency resource reserved by the terminal device 20 is whether the time-frequency resource a1 corresponding to the resource a in the listening window, which is located after the resource a, overlaps (including all overlaps or partial overlaps). If there is an overlap, i.e. a resource collision 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 resources remaining 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 according to the time period T₂₀If a plurality of the distributed time-frequency resources all need to transmit data, then at this time, if the terminal device 30 reserves the time period T₃₀A plurality of the time-frequency resources are distributed,and a time period T₂₀Satisfy T₂₀×M＝T₃₀Xn, M and N being positive integers, the terminal device 20 will follow the time period T₂₀The distributed plurality of time frequency resources are excluded from the candidate resource set.

(3) If the remaining resource quantity B in the candidate resource set S _ a is less than ax20%, the terminal device 20 may raise the psch-RSRP threshold by 3dB and repeat steps (0) to (2) until B ≧ ax20%.

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

(4) The terminal device 20 measures Received Signal Strength Indicators (RSSI) of the remaining B resources in the candidate resource set S _ a, sorts the B resources according to the measurement results from high to low, and moves a × 20% resources with the lowest Signal Strength to the candidate resource set S _ B.

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

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 multiple time-frequency resources may exist in the candidate resource set in each selection window for transmitting the data channel. For example, the resources a1 and B1 in fig. 3 may both be referred to as a time-frequency resource.

When the terminal device 20 selects the time-frequency Resource for data transmission, it will continuously use the time-frequency Resource in each transmission period of the subsequent transmission process, and use the time-frequency Resource C _ delay times in total, where C _ delay is a Resource Reselection Counter (Resource Reselection Counter), and when data is transmitted once, the value of C _ delay is decreased by 1, and when the value of C _ delay is decreased to 0, the terminal device 20 will generate a random number between [0 and 1], and compare the random number with a Resource retention Probability (ProbResourceKeep) parameter, where the parameter represents a Probability that the terminal device continues to use the Resource, and if the value of the random number is greater than the parameter, the terminal device 20 performs Resource Reselection, and if the value of the random number is less 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 _ delay.

In the vehicle networking system supporting multi-carrier transmission, whether the terminal device uses the transmission mode 3 or the transmission mode 4, the terminal device can use one or more carriers in the candidate multiple carriers for current data transmission. A terminal device using transmission mode 4 may select one or more carriers among a plurality of candidate carriers for current data transmission, while a terminal device using transmission mode 3 may perform current data transmission according to the one or more carriers selected by the base station.

The terminal device may measure a congestion degree of the system, for example, measure a Channel Busy Ratio (CBR), and the base station may instruct the terminal device to report a measurement result to the base station, so that the base station configures transmission parameters, such as a Modulation Coding Mode (MCS) allowed by the terminal device, a number range of usable Physical resource blocks (PBRs), and transmission times of retransmission according to the CBR reported by the terminal device. The CBR may be used for the terminal device to perform carrier selection in multiple carriers, for example, the terminal device may select a carrier with the lowest CBR for data transmission according to CBR measurement results of multiple carriers.

Wherein the CBR reflects the channel occupancy within the past 100 ms. The lower the CBR, the lower the system resource occupancy rate, the more available resources; the higher the CBR, the higher the system resource occupancy, the more congested and the more susceptible to transmission collisions and interference. However, for some services with low latency requirements, for example, services with a latency less than or equal to 10ms, at this time, the carrier selected by the terminal device according to the CBR of the multiple carriers in the past 100ms may not necessarily meet the latency requirement of the service to be transmitted by the terminal device, that is, the most appropriate transmission resource may not be selected within the latency requirement (for example, 10ms) of the service to transmit the service.

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

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

in 410, the terminal device obtains CBRs of multiple carriers within a subframe [ n-P, n-P + (T-1) ].

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

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

Therefore, the terminal device selects the target carrier used for transmitting the target service according to the channel occupation ratio CBR of the plurality of carriers in the subframe [ n-P, n-P + (T-1) ], wherein the time delay T of the target service to be transmitted is considered, so that effective carrier selection can be realized under the condition of meeting the time delay requirement.

For example, the terminal device may obtain the channel occupancy ratios CBR of the multiple carriers in the subframe [ n-P, n-P + (T-1) ], and select the carrier with the minimum CBR among the multiple carriers as the target carrier for transmitting the target service according to the CBR of the multiple carriers.

Optionally, in 420, the selecting, by the terminal device, the carrier in the multiple carriers according to the CBRs of the multiple carriers includes: the terminal equipment respectively carries out filtering processing on the CBRs of the multiple carriers according to the CBRs of the multiple carriers so as to obtain the filtered CBRs of the multiple carriers; selecting the target carrier from the plurality of carriers according to the filtered CBRs of the plurality of carriers.

Specifically, the terminal device obtains CBRs of the multiple carriers in the subframe [ n-P, n-P + (T-1) ], and performs filtering processing on the CBRs of the multiple carriers respectively to obtain filtered CBRs of the multiple carriers. And then selecting the target carrier from the plurality of carriers according to the filtered CBRs of the plurality of carriers.

Because the CBR of each carrier may change rapidly with the change of the location of the terminal device or change with the change of time, the CBR of each carrier changes smoothly by filtering the measured value of the CBR of each carrier, so that the frequency selected by the carrier is reduced, and the stability of the system is ensured.

Optionally, the filtering the CBRs of the multiple carriers includes: and performing smooth filtering on the CBRs of the multiple carriers.

The embodiment of the present application does not limit the smoothing filtering method.

For example, the smoothing filtering may be performed in a manner of CBR _ new ═ a × CBR _ old + (1-a) × CBR _ current.

The CBR _ new is the CBR of each carrier after filtering, the CBR _ current is the CBR of each carrier before filtering, the CBR _ old is the CBR of each carrier after last filtering, and a is a filter coefficient and is more than or equal to 0 and less than or equal to 1.

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

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

in 510, the physical layer of the terminal device performs resource sensing on multiple carriers within a time interval [ n + T1, n + T2], where n is a time when a target service to be transmitted arrives, or a time when carrier selection or resource selection is determined to be required for the terminal device, and T1 is greater than or equal to 0 and is less than T2.

Wherein, optionally, T2 is less than or equal to the delay of the target traffic.

Therefore, the terminal equipment considers the time delay of the target service, so that the effective carrier selection can be realized under the condition of meeting the time delay requirement.

In 520, the physical layer of the terminal device determines, according to the result of the resource sensing, an available resource set available for transmitting the target service on the multiple carriers and multiple physical sidelink shared channel reference signal received power psch-RSRP thresholds corresponding to the multiple carriers.

And the PSSCH-RSRP of the resources 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 selects the carrier according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers to obtain a target carrier for transmitting the target service.

Specifically, the physical layer of the terminal device performs resource sensing on multiple candidate carriers within a time interval [ n + T1, n + T2], and determines an available resource set on the multiple carriers for transmitting the target service according to a sensing result. Where n is the time when the target service arrives, or n is the time when the first terminal device determines that carrier selection or resource selection is required, for example, if the target service arrives before n time, the physical layer of the first terminal device may receive a request sent by its higher layer at n time, so that the physical layer of the first terminal device determines that carrier selection or resource selection is required within a time interval [ n + T1, n + T2] at n time to find transmission resources for the target service.

The process of the terminal device determining the available resource set on each carrier may refer to, for example, steps (0) to (4) in the description of fig. 3. For example, assuming that the plurality of carriers includes a first carrier, the terminal device performs resource sensing on the first carrier in a time interval [ n + T1, n + T2], excludes resources, which have PSSCH-RSRP measurement values higher than a PSSCH-RSRP threshold and are occupied and reserved by other terminal devices, according to the sensing result, and further selects, from the remaining resources, which have the lowest RSSI measurement value and account for 20% of the total number of resources in the selection window, wherein the selected 20% of resources constitute the available resource set on the first carrier. The available resource set can be understood as a candidate resource set S _ B obtained after the step (4) is completed. And the PSSCH-RSRP threshold corresponding to the first carrier is the PSSCH-RSRP threshold used when B is more than or equal to Ax 20% in the step (2) or (3) finally.

It should be understood that, for the methods for acquiring the available resource sets on other carriers besides the first carrier among the multiple carriers and the methods for acquiring the PSSCH-RSRP thresholds corresponding to other carriers, reference may be made to the description of the first carrier, and details are not described herein for brevity.

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

Mode 1

Optionally, the determining, by the terminal device, a target carrier for transmitting the target service according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers includes: and the physical layer of the terminal equipment selects a carrier with the minimum PSSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

Further, optionally, the method further comprises: the physical layer of the terminal equipment reports the available resource set on the target carrier to the high layer of the terminal equipment, and/or the physical layer of the terminal equipment reports the index of the target carrier to the high layer of the terminal equipment; and the higher layer of the terminal equipment selects resources for transmitting the target service from the available resource set on the target carrier.

Mode 2

Optionally, the determining, by the terminal device, a target carrier for transmitting the target service according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers includes: the physical layer of the terminal equipment reports a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers to the high layer of the terminal equipment; and the high layer of the terminal equipment selects the carrier with the minimum PSSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

Further, optionally, the method further comprises: the physical layer of the terminal equipment reports the available resource sets on the multiple carriers to the high layer of the terminal equipment; and the higher layer of the terminal equipment selects resources for transmitting the target service from the available resource set on the target carrier.

It can be seen that, in mode 1, a physical layer of the terminal device selects a carrier with the smallest psch-RSRP threshold from a plurality of psch-RSRP thresholds corresponding to the plurality of carriers as the target carrier, and reports an available resource set on the target carrier and/or an index of the target carrier to its higher layer. And the higher layer of the terminal equipment selects resources for transmitting the target service from the available resource set on the target carrier.

In the method 2, after the physical layer of the terminal device determines the multiple psch-RSRP thresholds corresponding to the multiple carriers, the physical layer may directly report the multiple psch-RSRP thresholds to the higher layer of the terminal device, and the higher layer selects the carrier with the minimum psch-RSRP threshold as the target carrier. And the physical layer of the terminal device may also report the determined available resource sets on the multiple carriers at the same time, so that the higher layer of the terminal device selects the resource for transmitting the target service from the available resource sets on the target carrier.

It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Having described the method for carrier selection in D2D communication according to the embodiment of the present application in detail, an apparatus according to the embodiment of the present application will be described below with reference to fig. 6 to 9, and the technical features described in the method embodiment are applicable to the following apparatus embodiments.

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. Wherein:

an obtaining module 610, configured to obtain channel occupancy ratios CBR of multiple carriers in a subframe [ n-P, n-P + (T-1) ], where T is a time delay of a target service to be transmitted, and subframe n is a time when the target service arrives, or a time when carrier selection or resource selection needs to be performed is determined for the terminal device;

a carrier selecting module 620, configured to select a carrier among the multiple carriers according to the CBRs of the multiple carriers acquired by the acquiring module 610, so as to acquire a target carrier for transmitting the target service.

Therefore, the terminal equipment selects the target carrier used for transmitting the target service according to the channel occupation ratio CBR of the plurality of carriers in the subframe [ n-P, n-P + (T-1) ] based on the time delay T of the target service to be transmitted, so that the effective carrier selection can be realized under the condition of meeting the time delay requirement.

Optionally, the carrier selecting module 620 is specifically configured to: respectively carrying out filtering processing on the CBRs of the multiple carriers to obtain filtered CBRs of the multiple carriers; selecting the target carrier from the plurality of carriers according to the filtered CBRs of the plurality of carriers.

Optionally, the carrier selecting module 620 is specifically configured to: and performing smooth filtering on the CBRs of the multiple carriers respectively.

Optionally, the CBR of each of the plurality of carriers after the smoothing filtering 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 last filtering, a is a filter coefficient, and a is greater than or equal to 0 and less than or equal to 1.

Optionally, the carrier selecting module 620 is specifically configured to: and selecting the carrier with the minimum CBR from the plurality of carriers as the target carrier according to the CBRs of the plurality of carriers.

It should be understood that the terminal device 600 may perform corresponding operations of the method 400 performed by the terminal device in the foregoing method embodiments, 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 higher layer module 720. Wherein:

the physical layer module 710 is configured to perform resource sensing on multiple carriers within a time interval [ n + T1, n + T2], where n is a time when a target service to be transmitted arrives, or a time when carrier selection or resource selection is determined to be required for the terminal device, and T1 is greater than or equal to 0 and is less than T2;

the physical layer module 710 is further configured to determine, according to a result of the resource sensing, available resource sets on the multiple carriers that can be used for transmitting the target service, and multiple physical sidelink shared channel reference signal received power PSSCH-RSRP thresholds corresponding to the multiple carriers, where a PSSCH-RSRP of a resource in the available resource sets on each carrier is less than or equal to the PSSCH-RSRP threshold corresponding to each carrier;

the physical layer module 710 is further configured to select the carrier according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers, so as to obtain a target carrier for transmitting the target service; or

The high-layer module 720 is further configured to select the carrier according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers, so as to obtain a target carrier for transmitting the target service.

Therefore, in the process of determining the available resource set on the multiple carriers, the terminal device can obtain multiple psch-RSRP thresholds corresponding to the multiple carriers, and effectively select the carriers according to the multiple psch-RSRP thresholds corresponding to the multiple carriers, so that the terminal device in the system supporting multi-carrier transmission can obtain resources in the selected carriers to perform data transmission.

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

Optionally, the physical layer module 710 is further configured to: reporting the set of available resources on the target carrier to the higher-layer module 720, and/or reporting the index of the target carrier to the higher-layer module 720 by the physical layer module 710; the higher layer module 720 is further configured to select a resource for transmitting the target service from the set of available resources on the target carrier.

Optionally, the physical layer module 710 is further configured to: reporting a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers to the high-level module 720; the higher layer module 720 is specifically configured to select, according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers, a carrier with a minimum psch-RSRP threshold from the plurality of carriers as the target carrier.

Optionally, the physical layer module 710 is further configured to: reporting the set of available resources on the plurality of carriers to the higher layer module 720; the higher layer module 720 is further configured to select a resource for transmitting the target service from the set of available resources on the target carrier.

Optionally, T2 is less than or equal to the latency of the target traffic.

It should be understood that the terminal device 700 may perform corresponding operations of the method 500 performed by the terminal device in the foregoing method embodiments, and details are not described herein for brevity.

Fig. 8 is a schematic configuration 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 used for storing instructions, and the processor 810 is used for executing the instructions stored in the memory 830 to control the transceiver 820 to receive signals or transmit signals.

Optionally, the processor 810 may 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, which are not described herein again for brevity.

Optionally, the processor 810 may call the program code stored in the memory 830 to perform the corresponding operations of the method 500 executed by the terminal device in the method embodiment, which are not described herein again for brevity.

It should be understood that the processor of the embodiments of the present application may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The Processor may be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of example, but not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic random access memory (DDR SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchronous link SDRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory of the systems and methods described herein is 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, where the input interface 901, the output interface 902, the processor 903, and the memory 904 are connected to each other through an internal connection path. The processor 903 is used to execute the code in the memory 904.

Optionally, when the code is executed, the processor 903 may implement the method 400 executed by the terminal device in the method embodiment. For brevity, no further description is provided herein.

Optionally, when the code is executed, the processor 903 may implement the method 500 executed by the terminal device in the method embodiment. For brevity, no further description is provided herein.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the unit is only one logical functional division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

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

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for carrier selection in device-to-device D2D communication, the method comprising:

a physical layer of terminal equipment carries out resource interception on a plurality of carriers within a time interval [ n + T1, n + T2], wherein n is the time when a target service to be transmitted arrives or the time when the terminal equipment determines that carrier selection or resource selection needs to be carried out, and T1 is more than or equal to 0 and less than T2;

the physical layer of the terminal device determines an available resource set which can be used for transmitting the target service on the multiple carriers and multiple physical sidelink shared channel reference signal received power PSSCH-RSRP thresholds corresponding to the multiple carriers according to the result of the resource monitoring, wherein the resources in the available resource set are the resources with the lowest RSSI measurement value and account for 20% of the total number of resources in [ n + T1, n + T2 ]; the PSSCH-RSRP of the resources in the available resource set on each carrier is less than or equal to the PSSCH-RSRP threshold corresponding to each carrier;

and the terminal equipment selects the carrier according to a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers so as to acquire a target carrier for transmitting the target service.

2. The method of claim 1, wherein the terminal device determines a target carrier for transmitting the target service according to a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers, and comprises:

and the physical layer of the terminal equipment selects a carrier with the minimum PSSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

3. The method of claim 2, further comprising:

the physical layer of the terminal equipment reports the available resource set on the target carrier to the high layer of the terminal equipment, and/or the physical layer of the terminal equipment reports the index of the target carrier to the high layer of the terminal equipment;

and the high layer of the terminal equipment selects resources for transmitting the target service from the available resource set on the target carrier.

4. The method of claim 1, wherein the terminal device determines a target carrier for transmitting the target service according to a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers, and comprises:

the physical layer of the terminal equipment reports a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers to the high layer of the terminal equipment;

and the high layer of the terminal equipment selects a carrier with the minimum PSSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

5. The method of claim 4, further comprising:

the physical layer of the terminal equipment reports the available resource sets on the multiple carriers to the high layer of the terminal equipment;

6. The method of any of claims 1-5, wherein T2 is less than or equal to a latency of the target traffic.

7. A terminal device, characterized in that the terminal device comprises a physical layer module and a higher layer module, wherein:

the physical layer module is configured to perform resource sensing on multiple carriers within a time interval [ n + T1, n + T2], where n is a time when a target service to be transmitted arrives, or a time when carrier selection or resource selection is required to be performed is determined for the terminal device;

the physical layer module is further configured to determine, according to a result of the resource sensing, an available resource set available for transmitting the target service on the multiple carriers and multiple physical sidelink shared channel reference signal received power psch-RSRP thresholds corresponding to the multiple carriers, where a resource in the available resource set is a resource that occupies 20% of a total number of resources in [ n + T1, n + T2] with a lowest RSSI measurement value; the PSSCH-RSRP of the resources in the available resource set on each carrier is less than or equal to the PSSCH-RSRP threshold corresponding to each carrier;

the physical layer module is further configured to select the carrier according to a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers, so as to obtain a target carrier for transmitting the target service; or

And the high-level module is further configured to select the carrier according to a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers, so as to obtain a target carrier for transmitting the target service.

8. The terminal device of claim 7, wherein the physical layer module is specifically configured to:

and selecting the carrier with the minimum SSCH-RSRP threshold from the multiple carriers as the target carrier according to the multiple PSSCH-RSRP thresholds corresponding to the multiple carriers.

9. The terminal device of claim 8, wherein the physical layer module is further configured to:

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

the higher layer module is further configured to select a resource for transmitting the target service from the available resource set on the target carrier.

10. The terminal device of claim 7, wherein the physical layer module is further configured to:

reporting a plurality of PSSCH-RSRP thresholds corresponding to the plurality of carriers to the high-level module;

the higher-layer module is specifically configured to select, according to a plurality of psch-RSRP thresholds corresponding to the plurality of carriers, a carrier with a minimum psch-RSRP threshold among the plurality of carriers as the target carrier.

11. The terminal device of claim 10, wherein the physical layer module is further configured to:

reporting the available resource sets on the multiple carriers to the high-level module;

12. The terminal device according to any of claims 7 to 11, wherein T2 is less than or equal to the latency of the target traffic.