Method, apparatus and base station for selecting pc5 carrier

Abstract

Embodiments of the present application provide a PC5 carrier frequency selection method, device, equipment and base station, when a V2X sender needs to send V2X service data using a carrier frequency, a V2X sender device can obtain an initial candidate carrier frequency set of the V2X service data according to a service identifier of the V2X service data and a service identifier-carrier frequency mapping relationship, and further select a carrier frequency that meets the conditions from the initial candidate carrier frequency set as a transmission carrier frequency of the V2X service data to transmit the V2X service data, so that more accurate selection and matching of the carrier frequency can be realized; when the receiving capability of the receiver is limited, the V2X receiver device can select M carrier frequencies that can be simultaneously received within its own capability as receiving carrier frequencies in the order from high to low according to the priority of the target service identifier of each V2X service data, so that the reception of the high-priority V2X of interest to the user can be ensured, and the satisfaction of the user experience can be improved.

Description

Technical Field

[0001] This invention relates to the field of communications, and more particularly to a PC5 carrier frequency selection method, apparatus, device, and base station. Background Technology

[0002] With the development of communication technology and the enrichment of demands, the application scenarios of wireless communication are becoming increasingly widespread, among which vehicle networking (V2X) is a typical example. V2X allows vehicles to participate in wireless communication, utilizing advanced cellular communication technology to achieve real-time information exchange between vehicles and between vehicles and roadside infrastructure. This enables them to share their current status (including vehicle location, speed, acceleration, and driving path) and road environment information, collaboratively perceive road hazards, and provide timely collision warnings to prevent road traffic accidents. Currently, V2X communication modes are specifically divided into three categories: vehicle-to-vehicle communications (V2V), vehicle-to-infrastructure communications (V2I), and vehicle-to-pedestrian communications (V2P). These three categories can also be collectively referred to as V2X (Vehicle-to-Everything) communication.

[0003] In V2X vehicle-to-everything (V2X) communication, V2X messages can be transmitted via broadcast. One implementation of broadcasting is based on UE-to-UE direct discovery / communication (D2D, sidelink, ProSe), which supports broadcast transmission of V2X messages through the PC5 interface (an interface introduced in 3GPP Rel-12 for direct interaction between UEs). With the development of V2X communication, the demand for high reliability and / or high-speed transmission of V2X service data is becoming increasingly urgent, requiring the same V2X service data to be transmitted using multiple carrier frequencies. This places increasingly higher demands on the accuracy of carrier frequency selection for data transmission. Correspondingly, for the receiving UE, due to its limited receiving capabilities, it may not be able to simultaneously receive V2X service data transmitted by the sender using multiple carrier frequencies. Therefore, it is necessary to solve the problem of how the receiving UE with limited receiving capabilities determines the carrier frequency to receive. Summary of the Invention

[0004] The present invention provides a PC5 carrier frequency selection, V2X service data transmission and reception method, apparatus and equipment, which mainly solves the following technical problems: how to improve the accuracy of carrier frequency selection, and how to determine the carrier frequency to be received when the receiving capability of the V2X receiver is limited.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a PC5 carrier frequency selection method, comprising:

[0006] The initial candidate carrier frequency set of the V2X service data is obtained based on the service identifier and the service identifier-carrier frequency mapping relationship of the V2X service data.

[0007] The transmission carrier frequency for the V2X service data is selected from the initial candidate carrier frequency set based on the carrier frequency selection information.

[0008] This invention also provides a PC5 carrier frequency selection method, including:

[0009] Receive carrier frequency selection assistance information sent by V2X transmitting device, wherein the carrier frequency selection assistance information includes an initial candidate carrier frequency set of V2X service data obtained according to the service identifier of V2X service data and the service identifier-carrier frequency mapping relationship;

[0010] Send carrier frequency selection control information to the V2X transmitting device.

[0011] This invention also provides a PC5 carrier frequency selection method, including:

[0012] Obtain the priority corresponding to the service identifier or a list of service identifiers sorted by priority;

[0013] Based on the priority corresponding to the service identifier or the list of service identifiers sorted by reception priority, select the carrier frequencies corresponding to M higher priority services that can be received simultaneously within the range supported by the PC5 multi-carrier reception capability as the reception carrier frequencies, where M is an integer greater than or equal to 1.

[0014] This invention also provides a PC5 carrier frequency selection device, comprising:

[0015] The initial selection module is used to obtain an initial candidate carrier frequency set for the V2X service data based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency.

[0016] The carrier frequency determination module is used to select the transmission carrier frequency of the V2X service data from the initial candidate carrier frequency set according to the carrier frequency selection information.

[0017] This invention also provides a PC5 carrier frequency selection device, comprising:

[0018] The information receiving module is used to receive carrier frequency selection assistance information sent by the V2X transmitting device. The carrier frequency selection assistance information includes an initial candidate carrier frequency set of the V2X service data obtained according to the service identifier of the V2X service data and the service identifier-carrier frequency mapping relationship.

[0019] The configuration processing module is used to send carrier frequency selection control information to the V2X transmitting device.

[0020] This invention also provides a PC5 carrier frequency selection device, comprising:

[0021] The service acquisition module is used to obtain the priority corresponding to the service identifier or a list of service identifiers sorted by priority.

[0022] The carrier frequency acquisition module is used to select, within the range supported by the PC5 multi-carrier frequency reception capability, the carrier frequencies corresponding to M higher priority services that can be received simultaneously as receiving carrier frequencies, based on the priority corresponding to the service identifier or a list of service identifiers sorted by reception priority. M is an integer greater than or equal to 1.

[0023] This invention also provides a V2X transmitter device, which includes a first processor, a first memory, and a first communication bus.

[0024] The first communication bus is used to realize the connection and communication between the first processor and the first memory;

[0025] The first processor is used to execute one or more first programs stored in the first memory to implement the steps of the PC5 carrier frequency selection method as described above.

[0026] This invention also provides a base station, which includes a second processor, a second memory, and a second communication bus;

[0027] The second communication bus is used to realize the connection and communication between the second processor and the second memory;

[0028] The second processor is used to execute one or more third programs stored in the second memory to implement the steps of the PC5 carrier frequency selection method as described above.

[0029] This invention also provides a V2X receiver device, which includes a third processor, a third memory, and a third communication bus.

[0030] The third communication bus is used to realize the connection and communication between the third processor and the third memory;

[0031] The third processor is used to execute one or more third programs stored in the third memory to implement the steps of the PC5 carrier frequency selection method as described above.

[0032] This invention also provides a computer storage medium storing one or more first programs, which are executed by one or more processors to implement the steps of the PC5 carrier frequency selection method described above.

[0033] The beneficial effects of this invention are:

[0034] According to the PC5 carrier frequency selection method, apparatus, device, base station, and storage medium provided in the embodiments of the present invention, when a V2X transmitter needs to use a carrier frequency to transmit V2X service data, the V2X transmitter device can obtain an initial candidate carrier frequency set for the V2X service data based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency. It can then further select carrier frequencies that meet the conditions from the initial candidate carrier frequency set using carrier frequency selection information to transmit the V2X service data, thereby achieving more accurate carrier frequency selection and matching. When the receiver's receiving capability is limited, the V2X receiver device can select M carrier frequencies that can be simultaneously received within the range supported by its own PC5 multi-carrier frequency receiving capability information, according to the priority order corresponding to the target service identifier of each V2X service data from high to low, thereby ensuring the reception of high-priority V2X services of interest to the user and improving user experience satisfaction.

[0035] Other features and corresponding beneficial effects of the present invention will be described in the latter part of the specification, and it should be understood that at least some of the beneficial effects will become obvious from the description in the specification. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the PC5 carrier frequency selection method according to Embodiment 1 of the present invention;

[0037] Figure 2 This is a schematic diagram of the PC5 carrier frequency selection process in accordance with carrier frequency selection control information in Embodiment 1 of the present invention;

[0038] Figure 3 This is a schematic diagram of the PC5 carrier frequency selection method according to Embodiment 2 of the present invention;

[0039] Figure 4 This is a schematic diagram of the PC5 carrier frequency selection device according to Embodiment 3 of the present invention;

[0040] Figure 5 This is a schematic diagram of the V2X transmitting device structure according to Embodiment 3 of the present invention;

[0041] Figure 6 This is a schematic diagram of another PC5 carrier frequency selection device according to Embodiment 3 of the present invention;

[0042] Figure 7This is a schematic diagram of the base station structure according to Embodiment 3 of the present invention;

[0043] Figure 8 This is a schematic diagram of the transmission carrier frequency selection method for a mode 4 UE in the RRC idle state according to Embodiment 3 of the present invention;

[0044] Figure 9 This is a schematic diagram of the transmission carrier frequency selection method for a mode 4 UE in RRC connection state according to Embodiment 4 of the present invention;

[0045] Figure 10 This is a schematic diagram of the transmission carrier frequency selection method for a mode 3 UE in RRC connection state according to Embodiment 5 of the present invention;

[0046] Figure 11 This is a schematic diagram of communication between Vehicle UEs in Embodiment 5 of the present invention. Figure 1 ;

[0047] Figure 12 This is a schematic diagram of communication between Vehicle UEs in Embodiment 5 of the present invention. Figure 2 ;

[0048] Figure 13 This is a schematic diagram of communication between Vehicle UEs in Embodiment 5 of the present invention. Figure 3 ;

[0049] Figure 14 This is a schematic flowchart of the PC5 carrier frequency selection method according to Embodiment Six of the present invention;

[0050] Figure 15 This is a schematic diagram of the PC5 carrier frequency selection device according to Embodiment Six of the present invention;

[0051] Figure 16 This is a schematic diagram of the V2X receiver device structure according to Embodiment Six of the present invention;

[0052] Figure 17 This is a schematic flowchart of the PC5 receiving carrier frequency selection method according to Embodiment Six of the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the embodiments of this invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0054] Example 1:

[0055] In V2X vehicle-to-everything (V2X) communication, V2X messages can be transmitted via multicast or broadcast. One implementation of multicast is based on MBSFN (Multicast Broadcast Single Frequency Network) and SC-PTM (Single-cell point-to-multiple-point) broadcast mechanisms, supporting V2X message broadcast transmission via the Uu interface. Another implementation of broadcast is based on UE-to-UE direct discovery / communication (D2D, sidelink, ProSe), supporting V2X message broadcast transmission via the PC5 interface (an interface introduced in 3GPP Rel-12 for direct interaction between UEs). Traditional base station-centric cellular networks have significant limitations in supporting high data rates and proximity services, failing to meet the demands of these requirements. The application of D2D technology can reduce the burden on cellular networks, decrease battery power consumption of user equipment, increase data rates, and improve the robustness of network infrastructure, effectively meeting the requirements of high data rate services and proximity services. Therefore, V2X communication can also use D2D to meet the requirements of high data rate services and proximity services. Currently, D2D technology is also known as Proximity Services (ProSe) or SideLink (SL).

[0056] Similarly, in V2X communication, high reliability and / or high-speed data transmission is a widespread demand and development trend. To achieve high reliability and / or high-speed transmission of V2X service data, it is necessary to transmit V2X service data using multiple carrier frequencies. This places higher demands on the accuracy of carrier frequency selection and requires solving the problem of how to select the necessary multiple carrier frequencies. This embodiment provides a PC5 carrier frequency selection method to address this problem. In this embodiment, the PC5 carrier frequency refers to the carrier frequency used when transmitting through the PC5 interface. The PC5 carrier frequency selection method is described in [reference needed]. Figure 1 As shown, it includes:

[0057] S101: The V2X transmitting device obtains the initial candidate carrier frequency set of the V2X service data based on the service identifier of the V2X service data and the service identifier-carrier frequency mapping relationship.

[0058] It should be understood that the V2X transmitting device in this embodiment can be either an in-vehicle terminal device or a user terminal device. The specific choice depends on the specific vehicle-to-everything (V2X) communication mode. Furthermore, the V2X transmitting device in this embodiment also serves as the V2X service data receiver.

[0059] In this embodiment, the service identifier and carrier frequency mapping relationship can be represented by a service identifier and a V2X carrier frequency mapping relationship table. The service identifier and carrier frequency mapping relationship in this embodiment can also be configured on the V2X transmitting device through pre-configuration; of course, it can also be set on the V2X transmitting device in other ways.

[0060] In this embodiment, after obtaining the service identifier, the service identifier is queried in the service identifier-V2X carrier frequency mapping table to find the carrier frequency corresponding to the service identifier. All carrier frequencies corresponding to the service identifier then form an initial candidate carrier frequency set. Furthermore, the service identifier can be specifically passed from the higher layers of the V2X transmitting device to the lower layers of the V2X transmitting device.

[0061] S102: The V2X transmitting device selects the transmission carrier frequency for V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information. Further selecting the transmission carrier frequency from the initial candidate carrier frequency set based on the carrier frequency selection information can improve the accuracy of carrier frequency selection.

[0062] In this embodiment, the V2X transmitting device selects the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information. This includes the process by which the V2X transmitting device uses the carrier frequency selection information to delete carrier frequencies that do not meet the conditions in the initial candidate carrier frequency set to obtain a valid candidate carrier frequency set.

[0063] In this embodiment, the specific carrier frequency selection information and selection method used by the V2X transmitting device can be flexibly selected according to the current connection status of the V2X transmitting device and the current resource allocation mode.

[0064] For example, in V2X communication, two resource allocation modes are supported: 1) Scheduled resource allocation (also known as mode 3). In this mode, the UE needs to enter the RRC connected state to request resources for transmission from the base station. The UE requests resources by sending a sidelink UE information message to the base station. Of course, in this embodiment, resources can also be requested by sending other messages to the base station, not limited to the sidelink UE information message. 2) UE autonomous resource selection (also known as mode 4). In this mode, the UE autonomously selects resources from the resource pool based on sensing for SCI (Sidelink Control Information) and data transmission; this method can be used for UEs in the RRC idle state or the RRC connected state.

[0065] Therefore, in this embodiment, when the V2X transmitting device is in RRC idle state, the V2X transmitting device can adopt mode 4 mode. It can select the carrier frequency using its own information and information obtained from the base station or other sources. In this embodiment, the information obtained from the base station for carrier frequency selection can be referred to as carrier frequency selection control information. At this time, the V2X transmitting device can obtain the relevant carrier frequency selection control information from the base station through system messages. Of course, it should be understood that the carrier frequency selection control information is not limited to being obtained from the base station; it may be obtained through pre-configuration or from the physical layer.

[0066] When the V2X transmitter is in RRC connection mode, it can flexibly choose between mode 3 and mode 4. In this mode, the V2X transmitter can send relevant information for carrier frequency selection to the base station, which then selects the carrier frequency. In this embodiment, the information sent by the V2X transmitter to the base station for carrier frequency selection is called carrier frequency selection auxiliary information. Of course, in this scenario, carrier frequency selection can also be achieved by combining the V2X transmitter and the base station. For example, the V2X transmitter (which may or may not use carrier frequency selection control information) completes some steps of carrier frequency selection, while the base station completes other steps (which may or may not use carrier frequency selection auxiliary information). In this scenario, the V2X transmitting device can also select the carrier frequency by obtaining carrier frequency selection control information from the base station, similar to when it is in the RRC idle state. At this time, the V2X transmitting device can obtain the carrier frequency selection control information from the base station through RRC dedicated signaling. Of course, depending on the needs, it can also obtain the carrier frequency selection control information from the base station through other messages (such as system messages).

[0067] In this embodiment, the V2X transmitting device can select at least two carrier frequencies from the obtained set of valid candidate carrier frequencies as the transmission carrier frequencies for the V2X service data. Before selecting at least two carrier frequencies from the obtained set of valid candidate carrier frequencies, the V2X transmitting device can first determine whether the V2X service data needs to be transmitted using multiple carrier frequencies.

[0068] Based on the above analysis, in this embodiment, the number of carrier frequencies used for transmission may be determined by the V2X transmitting device or by the base station, and then the V2X transmitting device selects the appropriate number of carrier frequencies for transmission.

[0069] It should be understood that using multiple carrier frequencies to transmit V2X service data can be based on either high data rate requirements or high reliability requirements. When high data rate is required, multi-carrier data splitting can be used; when high reliability is required, multi-carrier data duplication can be used. Of course, both methods can also be combined depending on actual needs. When using multi-carrier data splitting, after determining at least two transmission carrier frequencies for the V2X service data, the proportion of data transmitted on each carrier frequency can also be determined. This proportion can be determined autonomously by the V2X transmitting device, by the base station, or jointly by the V2X transmitting device and the base station.

[0070] For example, in one instance, the carrier frequency selection information used by the V2X transmitter includes at least one of the following: synchronization reference timing information, channel busy ratio (CBR) threshold value of the V2X resource pool on the carrier frequency (which can be obtained from the base station or from other places), V2X transmitter PC5 multi-carrier transmission capability information, and V2X transmission carrier frequency set sent by the base station to the UE (i.e., a list of carrier frequencies that can be used for transmission sent by the base station).

[0071] At this time, the V2X transmitting device may use carrier frequency selection information to delete carrier frequencies that do not meet the conditions in the initial candidate carrier frequency set, including but not limited to at least one of the following:

[0072] The asynchronous timing aligned carrier frequencies in the initial candidate carrier frequency set are deleted using the synchronization reference timing information.

[0073] Delete carriers from the initial candidate carrier set whose Channel Busy Ratio (CBR) measurement value of the V2X resource pool on the carrier is greater than the CBR threshold value of the V2X resource pool on that carrier.

[0074] Based on the PC5 multi-carrier transmission capability information, select the maximum number of carrier frequencies within the capability range of the V2X transmitting device from the initial candidate carrier frequency set, and delete any other redundant carrier frequencies from the initial candidate carrier frequency set.

[0075] Obtain the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE, and delete the carrier frequencies in the initial candidate carrier frequency set that are not in the carrier frequency intersection.

[0076] It should be understood that the above steps can be flexibly combined, and the timing relationship between each step can also be flexibly set. In order to facilitate understanding of the present invention, this embodiment will use V2X transmitting end device combined with carrier frequency selection control information obtained from base station to perform carrier frequency selection examples, and combine the above steps with a combination application example to further explain the present invention.

[0077] When a V2X transmitting device selects a carrier frequency using carrier frequency selection control information obtained from the base station, this information can be extracted from the base station by the V2X transmitting device, or it can be obtained from the base station in real time when needed by the V2X transmitting device. For the PC5 carrier frequency selection method in this case, please refer to [link to relevant documentation]. Figure 2 As shown, it includes:

[0078] S201: The V2X transmitting device obtains the initial candidate carrier frequency set for V2X service data based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency.

[0079] The V2X service data in this step can be data to be transmitted generated by the higher layer of the V2X transmitting device, or data to be transmitted from other sources. This V2X service data can be one or multiple. If multiple, then for each V2X service message, an initial set of candidate carrier frequencies for that V2X service message can be determined based on the corresponding service identifier and the service identifier-carrier frequency mapping relationship.

[0080] S202: The V2X transmitting device takes the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE as the valid candidate carrier frequency set.

[0081] At this point, the carrier frequency selection information includes the V2X transmission carrier frequency set sent by the base station to the UE. This V2X transmission carrier frequency set sent by the base station to the UE can be obtained by the V2X transmitting device from the base station in advance or in real time, or it can be obtained from other places. Through this step, V2X transmission carrier frequencies that are not supported by the base station can be removed from the initial candidate carrier frequency set.

[0082] In this step, the V2X transmitting device may be in a state of base station coverage or in a state of no coverage. When the V2X transmitting device is in a state of no coverage, the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE is empty, and the UE does not detect a suitable cell on the pre-configured V2X carrier frequency. At this time, the carrier frequency selection information also includes a V2X transmission carrier frequency set for the no-coverage situation; and this V2X transmission carrier frequency set for the no-coverage situation can be preset on the V2X transmitting device. At this time, the V2X transmitting device uses the carrier frequency selection information to select carrier frequencies that meet the conditions from the initial candidate carrier frequency set to form a valid candidate carrier frequency set, which includes:

[0083] When a V2X transmitting device is in a state of no coverage, it takes the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set under no coverage as the effective candidate carrier frequency set for subsequent carrier frequency selection.

[0084] In this embodiment, before executing S202, the V2X transmitting device maps V2X service data to the corresponding PC5 logical channel. During the mapping process, if the V2X service data does not have a corresponding logical channel, a new logical channel is created for it. The UE determines whether to use multi-carrier data duplication for transmission based on the reliability level / requirements of the V2X data. If multi-carrier data duplication is required, the UE establishes multiple logical channels for transmitting the data packet. The UE can use the initial candidate carrier frequency set obtained from the service identifier and the service identifier-carrier frequency mapping relationship of the V2X service data as the initial candidate carrier frequency set for the PC5 logical channel. Subsequently, the candidate carrier frequency set can be managed on a logical channel basis. However, it should be understood that this logical channel mapping step is optional. And the specific mapping rules in this embodiment can be flexibly set.

[0085] In this embodiment, after further selecting carrier frequencies by taking the intersection as described above, the carrier frequencies in the effective candidate carrier frequency set can be further filtered and selected by at least one of the following filtering methods. It should be understood that the execution of the following carrier frequency filtering process is optional, and there is no strict time limit for the execution order. The execution order of each step can be interchanged, and in some examples, they can even be executed in parallel.

[0086] S203: The effective candidate carrier frequency set is obtained by filtering the channel busy ratio (CBR) measurement value of the V2X resource pool on each carrier frequency in the effective candidate carrier frequency set and the corresponding CBR measurement value threshold value.

[0087] At this time, the carrier frequency selection control information includes the Channel Busy Ratio (CBR) threshold value of the V2X resource pool on the carrier frequency. In this embodiment, the V2X resource pool on the carrier frequency can be obtained from the base station or pre-configured on the device. The CBR threshold value can also be obtained from the base station or pre-configured on the device. Furthermore, there can be one or multiple CBR threshold values. When there are multiple CBR threshold values, different CBR threshold values ​​can be set according to different service types, Quality of Service (QoS) information, carrier frequencies, or resource pools. During filtering, the corresponding CBR threshold value is first selected based on the service type, QoS information, carrier frequency, or resource pool corresponding to the current V2X service data. Then, the threshold value and the corresponding CBR measurement value are used for further carrier frequency filtering. The QoS information in this embodiment includes, but is not limited to, at least one of Packet Priority (PPP), Data Rate, Data Reliability, and Packet Delay Budget. For example, in one example, the CBR threshold value obtained from the base station includes, but is not limited to, at least one of the following examples:

[0088] 1) CBR threshold value;

[0089] 2) CBR threshold values ​​and corresponding priorities;

[0090] 3) CBR threshold values ​​and corresponding data rates;

[0091] 4) CBR threshold values ​​and corresponding reliability;

[0092] 5) CBR threshold value and corresponding packet delay budget.

[0093] The screening process in this step includes:

[0094] V2X transmitting devices acquire the Channel Busy Ratio (CBR) measurement of the V2X resource pool on each carrier in the set of valid candidate carrier frequencies;

[0095] Carriers in the valid candidate carrier frequency set whose Channel Busy Ratio (CBR) measurement value of the V2X resource pool is greater than the CBR threshold value of the V2X resource pool on that carrier frequency are deleted. In other words, these carrier frequencies are considered unusable for transmission and are removed from the set; the remaining carrier frequencies are considered usable for transmission.

[0096] In this embodiment, after deleting carriers from the effective candidate carrier set whose Channel Busy Ratio (CBR) measurement value for the V2X resource pool is greater than the CBR threshold value for that carrier, the following optional step may be included: arranging the remaining carriers in the effective candidate carrier set in ascending order of their CBR measurement values ​​for the V2X resource pool. Alternatively, an equivalent approach could be to arrange them in descending order, in which case carrier selection could proceed from back to front.

[0097] In this embodiment, before or after executing S203, the V2X transmitting device can further use the synchronization reference timing information to filter out synchronized timing-aligned carrier frequencies from the set of valid candidate carrier frequencies and delete other carrier frequencies in the set of valid candidate carrier frequencies. The carrier frequency selection information at this time also includes synchronization reference timing information. The synchronization timing information includes one or a combination of the following: synchronization reference type, including: UE, GNSS, base station; coverage status of the synchronization source, used to indicate whether the synchronization source is within or outside coverage; and the absolute timing value of the synchronization source. In one example, the synchronization reference type is the synchronization reference type selected by the UE's physical layer.

[0098] S204: The V2X transmitting device selects the maximum number of carrier frequencies within its own capability range from the set of valid candidate carrier frequencies based on its own PC5 multi-carrier transmission capability information, and deletes any other redundant carrier frequencies from the set of valid candidate carrier frequencies.

[0099] At this time, the carrier frequency selection information also includes the V2X transmitter device's PC5 multi-carrier transmission capability information. In this embodiment, the PC5 multi-carrier transmission capability information includes at least one of the following: frequency band combination information supporting simultaneous PC5 transmission (which may include the maximum number of carrier frequencies supporting simultaneous PC5 transmission and which carrier frequencies can be used for simultaneous PC5 transmission), frequency band combination information supporting both PC5 and Uu transmission (which may include the maximum number of carrier frequencies supporting simultaneous PC5 and Uu transmission and which carrier frequencies can be used for simultaneous PC5 and Uu transmission), and transmission link Tx chain information.

[0100] The V2X transmitting device can determine its own capability range based on its current operating status (whether it uses PC5 and Uu transmission simultaneously, or only PC5 transmission) and / or the number of transmission links (Tx chains). For example, it may determine that it currently supports a maximum of 3 carrier frequencies for simultaneous PC5 transmission or PC5 and Uu transmission. Then, it selects the maximum number (e.g., 3) of carrier frequencies within its capability range from the set of valid candidate carrier frequencies and deletes the others. When the PC5 multi-carrier transmission capability information specifies which carrier frequencies to use, these specified carrier frequencies must also be selected when choosing the maximum number of carrier frequencies within its capability range from the set of valid candidate carrier frequencies. It should be understood that in this embodiment, the final number of carrier frequencies selected is less than or equal to the maximum number within the V2X transmitting device's own capability range.

[0101] S205: The V2X transmitting device determines whether V2X service data uses multi-carrier frequency transmission.

[0102] It should be understood that in this embodiment, the determination of whether V2X service data uses multi-carrier frequency transmission can be performed in or before any of the preceding steps, for example, it can be performed in step S202, or in or before other steps.

[0103] In this embodiment, the V2X transmitting device can determine whether V2X service data uses multi-carrier frequency transmission using any of the following methods:

[0104] Method 1: The V2X transmitting device determines whether the V2X service data uses multi-carrier frequency transmission based on the transmission parameters of the V2X service data and the corresponding transmission parameter threshold values.

[0105] Method 2: The V2X transmitting device determines whether the V2X service data uses multi-carrier frequency transmission based on the mapping relationship between the transmission parameters of the V2X service data and the corresponding number of carrier frequencies.

[0106] The transmission parameters include at least one of the following: buffer size and Quality of Service (QoS) information. In this embodiment, the QoS information includes, but is not limited to, at least one of Packet Priority (PPP), data rate, data reliability, and packet delay budget. It should be understood that the transmission parameters in this embodiment can be flexibly selected and combined.

[0107] For example, when using the above method one for judgment, the transmission parameter threshold value used includes, but is not limited to, at least one of the following threshold values:

[0108] 1) Packet priority PPPP threshold value. For example, if the PPPP value of a packet is greater than the priority threshold value, the PC5 multi-carrier (CA) function is not used; if the PPPP value of a packet is less than the priority threshold value, the PC5 CA function can be used, including at least one of data split and data duplication.

[0109] 2) Buffer size threshold;

[0110] 3) Data rate threshold;

[0111] 4) Delay budget threshold;

[0112] 5) Reliability threshold;

[0113] 6) Reliability and delay budget thresholds;

[0114] 7) Buffer size and delay budget threshold.

[0115] Correspondingly, when using method one, any one or more of the threshold values ​​in the above examples can be used, and one or more of the adjacent service packet priority PPPP value, buffer size value, data rate value, packet delay budget value, and reliability value (which can be characterized by reliability level information) can be compared with the corresponding threshold value.

[0116] The threshold values ​​described above in this embodiment can be obtained from the base station, specifically through system messages or RRC-specific commands. Of course, they can also be obtained through other means, such as pre-configuration. It should be understood that the above-described threshold values ​​are merely examples and can be flexibly extended or combined according to actual needs.

[0117] When using method two above, the mapping relationship between transmission parameters and the corresponding number of carrier frequencies includes, but is not limited to, at least one of the following examples:

[0118] 1) Buffer size range and corresponding number of carrier frequencies;

[0119] 2) Data rate range and corresponding number of carrier frequencies;

[0120] 3) Reliability range and corresponding number of carrier frequencies;

[0121] 4) Packet delay budget range and buffer size range and the corresponding number of carrier frequencies;

[0122] 5) Priority and corresponding number of carrier frequencies, specifically the number of carrier frequencies corresponding to the PPPP value or the range of PPPP values.

[0123] Correspondingly, when using method two, any one or more of the mapping relationships in the above examples can be used, along with one or more of the corresponding packet priority PPPP value, buffer size value, data rate value, packet delay budget value, and reliability value. By substituting these values ​​into the corresponding mapping relationship, the corresponding number of carrier frequencies can be matched. Based on the matched number of carrier frequencies, it can be determined whether multi-carrier transmission is required. For example, if the matched number of carrier frequencies is 1, it indicates that multi-carrier transmission is not required. If the matched number of carrier frequencies is an integer value greater than or equal to 2, it indicates that multi-carrier transmission is required.

[0124] The mapping relationships described in this embodiment can also be obtained from the base station, specifically through system messages or RRC-specific commands. Of course, they can also be obtained through other means, such as pre-configuration. It should be understood that the above-described mapping relationships are merely examples and can be flexibly extended or combined according to actual needs.

[0125] S206: When S205 determines that multi-carrier transmission is required, at least two carrier frequencies shall be selected from the above-mentioned set of valid candidate carrier frequencies as transmission carrier frequencies for V2X service data; this selection process includes:

[0126] If S205 uses the above-described method two for judgment, the required number of carrier frequencies can be obtained simultaneously with determining whether multi-carrier frequency transmission should be used. If method two is not used, the required number of carrier frequencies for V2X service data transmission can be determined based on the mapping relationship between the transmission parameters of the V2X transmitting device and the corresponding number of carrier frequencies. The specific determination process is shown in method two of S205 above. Then, based on the determined number of carrier frequencies, a corresponding number of carrier frequencies are selected from the set of valid candidate carrier frequencies as the transmission carrier frequencies for V2X service data. In one example, when selecting carrier frequencies, they can be chosen in ascending order of the CBR measurement values ​​of each carrier frequency in the set of valid candidate carrier frequencies.

[0127] In this embodiment, optionally, after changes in the CBR measurement results of each carrier frequency resource pool lead to a change in the order of carrier frequencies in the effective candidate carrier frequency set, subsequent carrier frequency selection can be performed immediately based on the updated carrier frequency list, or subsequent carrier frequency selection can be performed after a preset time period based on the updated effective candidate carrier frequency set. When the set of available frequency points changes, such as additions and / or deletions, subsequent carrier frequency selection can be performed immediately based on the updated effective candidate carrier frequency set (i.e., the set of available frequency points and the carrier frequency order).

[0128] In this embodiment, selecting at least two carrier frequencies from the above-mentioned set of valid candidate carrier frequencies as transmission carrier frequencies for V2X service data can also be achieved in the following manner:

[0129] First, select a carrier frequency from the set of valid candidate carrier frequencies to transmit the V2X service data. The selection can be made in ascending order of the CBR measurement values ​​of each carrier frequency in the set of valid candidate carrier frequencies.

[0130] Based on the sensing results, determine whether the selected carrier frequency meets the transmission requirements of V2X service data (the specific judgment method can be flexibly selected). If not, select another carrier frequency from the set of valid candidate carrier frequencies to transmit the V2X service data. Then, based on the sensing results, determine whether the selected carrier frequency meets the transmission requirements of V2X service data. Repeat the above process until the number of selected carrier frequencies meets the transmission requirements of V2X service data.

[0131] In this embodiment, when multiple carrier frequencies are used to transmit V2X service data based on the requirement of high data rate, after determining at least two transmission carrier frequencies for the V2X service data, the proportion of data transmitted on each transmission carrier frequency may also be determined. When the V2X transmitting device is in RRC idle or RRC connected state, the V2X transmitting device can autonomously determine the proportion of data transmitted on each transmission carrier frequency; when the V2X transmitting device is in RRC connected state, it can be determined autonomously by the V2X transmitting device or by the base station. For example, the determination can be based on factors such as the CBR measurement value of the resource pool on each carrier frequency and the size of the data packets to be transmitted; more data can be transmitted on resources on carrier frequencies with smaller CBR measurement values, and relatively less data can be transmitted on resources on carrier frequencies with larger CBR measurement values. When the V2X transmitting device determines the proportion autonomously, it can also combine the above parameters and factors such as the specific type of data to be transmitted.

[0132] As shown in the above analysis, when the V2X transmitting device is in RRC connection state, before selecting a carrier frequency that meets the conditions from the initial candidate carrier frequency set using carrier frequency selection information, the V2X transmitting device can also send corresponding carrier frequency selection assistance information to the base station to facilitate the base station's carrier frequency selection processing. In this embodiment, the carrier frequency selection assistance information sent to the base station includes, but is not limited to:

[0133] Logical channel identifier; logical channel group identifier; target identifier or target index number; QoS information; number of carrier frequencies; multi-carrier frequency indication information; wherein the multi-carrier frequency indication information is used to indicate whether multi-carrier frequency transmission, or multi-carrier frequency data split transmission, or multi-carrier frequency data duplication transmission, or multi-carrier frequency data split and data duplication transmission are used; V2X carrier frequency;

[0134] Synchronize timed information;

[0135] The synchronization timing information includes one or a combination of the following:

[0136] Synchronization reference types include: UE, GNSS, and base station;

[0137] The coverage status of the synchronization source indicates whether the synchronization source is within or outside the coverage area;

[0138] The absolute timing value of the synchronization source.

[0139] Among them, the logical channel ID, logical channel group identifier, target identifier or target index number mentioned above are all corresponding to the V2X service data.

[0140] The above example illustrates how a V2X transmitting device selects carrier frequencies using carrier frequency selection control information obtained from the base station. Using this carrier frequency selection method, when a V2X transmitter needs to use multiple carrier frequencies to transmit V2X service data, the V2X transmitting device can obtain an initial candidate carrier frequency set based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency. Then, using the carrier frequency selection information, it selects carrier frequencies that meet the conditions from the initial candidate carrier frequency set to form a valid candidate carrier frequency set. Finally, it selects at least two carrier frequencies from the obtained valid candidate carrier frequency set as the transmission carrier frequencies for the V2X service data to transmit the V2X service data, thus achieving reliable and effective selection and matching of multiple carrier frequencies.

[0141] Example 2:

[0142] To better understand this invention, the following explanation uses the example of a base station selecting a carrier frequency in conjunction with carrier frequency selection assistance information sent by a V2X transmitting device. In this case, the V2X transmitting device is in RRC connection mode and can use either mode 3 or mode 4. The carrier frequency selection assistance information includes transmission parameters corresponding to the V2X service data, which include at least one of the following: buffer size and Quality of Service (QoS) information. In this embodiment, the QoS information corresponding to the V2X service data can be characterized using a logical channel identifier and its corresponding QoS information, a target identifier and its corresponding QoS information, or a logical channel group identifier and its corresponding QoS information.

[0143] Optionally, if V2X data for the same target ID contains multiple QoS requirements, the PC5 signaling will only contain the highest QoS requirement information among the multiple QoS requirements; if the same logical channel group can be used to transmit data with multiple QoS requirements, the PC5 signaling will only contain the highest QoS requirement information among the multiple QoS requirements.

[0144] At this point, the V2X transmitting device uses the carrier frequency selection information to select carrier frequencies that meet the conditions from the initial candidate carrier frequency set to form a valid candidate carrier frequency set, including:

[0145] Send RRC messages (including but not limited to sidelink UE information messages) to the base station. The RRC messages include carrier frequency selection assistance information, which includes an initial candidate carrier frequency set.

[0146] The set of valid candidate carrier frequencies is obtained based on the RRC connection reconfiguration message received from the base station.

[0147] Correspondingly, see Figure 3 As shown, the base station performs the following steps:

[0148] S301: Receive carrier frequency selection assistance information sent by the V2X transmitting device. The carrier frequency selection assistance information includes an initial candidate carrier frequency set of the V2X service data obtained based on the service identifier of the V2X service data and the service identifier-carrier frequency mapping relationship.

[0149] Specifically, the base station can receive RRC messages sent by the V2X transmitting device. The RRC message includes carrier frequency selection assistance information, which includes an initial candidate carrier frequency set for the V2X service data obtained based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency.

[0150] S302: Send carrier frequency selection control information to the V2X transmitting device.

[0151] Specifically, an RRC connection reconfiguration message can be sent to the V2X transmitting device. The RRC connection reconfiguration message includes a set of valid candidate carrier frequencies obtained after deleting carrier frequencies that do not meet the conditions from the initial candidate carrier frequency set.

[0152] In this embodiment, the carrier frequency selection assistance information received by the base station may include at least one of synchronization reference timing information and PC5 multi-carrier transmission capability information of the V2X transmitter. The RRC connection reconfiguration message sent by the base station to the V2X transmitter includes a set of valid candidate carrier frequencies, which is obtained by the base station after performing at least one of the following processes on the initial candidate carrier frequency set:

[0153] Use synchronization reference timing information to remove carrier frequencies that are not synchronized in the initial candidate carrier frequency set;

[0154] Delete carriers from the initial candidate carrier set whose Channel Busy Ratio (CBR) measurement value of the V2X resource pool on the carrier is greater than the CBR threshold value of the V2X resource pool on that carrier.

[0155] Based on the PC5 multi-carrier transmission capability information, select the maximum number of carrier frequencies within the capability range of the V2X transmitting device from the initial candidate carrier frequency set, and delete any other redundant carrier frequencies from the initial candidate carrier frequency set;

[0156] Obtain the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent to the UE, and delete the carrier frequencies outside the carrier frequency intersection in the initial candidate carrier frequency set.

[0157] Referring to the analysis of Embodiment 1 above, the above steps can also be flexibly combined, and the timing can also be flexibly changed.

[0158] In one example, the carrier frequency selection assistance information sent by the V2X transmitting device to the base station also includes the transmission parameters corresponding to the V2X service data; the transmission parameters include at least one of buffer size and quality of service (QoS) information, and the QoS information includes at least one of proximity service packet priority (PPP), data rate, data reliability, and packet delay budget.

[0159] The base station can also generate at least one of the following carrier frequency selection control information based on the above parameters: multi-carrier frequency transmission indication information, carrier frequency quantity configuration information, etc., and the generation method can refer to the method of judgment based on these parameters by the V2X transmitting end device described above. At this time, the RRC connection reconfiguration message sent by the base station includes carrier frequency configuration information, which includes at least one of the following carrier frequency selection control information: multi-carrier frequency transmission indication information, carrier frequency quantity configuration information, etc. In one example, it may also include carrier frequency data offloading ratio configuration information.

[0160] In this embodiment, the RRC connection reconfiguration message received by the V2X transmitting device from the base station may also include resource allocation mode indication information, which indicates whether the V2X transmitting device adopts mode 3 or mode 4.

[0161] In this embodiment, when the carrier frequency configuration information fed back by the base station includes multi-carrier frequency transmission indication information, the V2X transmitting device may determine whether the V2X service data uses multi-carrier frequency transmission by: when the V2X transmitting device determines that the RRC connection reconfiguration message contains multi-carrier frequency transmission indication information, it may determine whether the V2X service data uses multi-carrier frequency transmission.

[0162] When the carrier frequency configuration information fed back by the base station includes carrier frequency quantity configuration information, at least two carrier frequencies are selected from the set of valid candidate carrier frequencies as the transmission carrier frequencies for V2X service data, including: the V2X transmitting device obtains the carrier frequency quantity configuration information from the RRC connection reconfiguration message;

[0163] The V2X transmitting device selects a corresponding number of carrier frequencies from the set of valid candidate carrier frequencies as the transmission carrier frequencies for V2X service data based on the carrier frequency quantity configuration information. In one example, the V2X transmitting device selects the carrier frequencies in ascending order of their CBR measurement values ​​from the set of valid candidate carrier frequencies.

[0164] When the carrier frequency configuration information fed back by the base station includes carrier frequency data offloading ratio configuration information, after the V2X transmitting device selects at least two carrier frequencies from the set of valid candidate carrier frequencies as the transmission carrier frequencies for the V2X service data, it also includes: determining the amount of data to be transmitted for each selected carrier frequency according to the carrier frequency data offloading ratio configuration information.

[0165] As can be seen, in this embodiment, the carrier frequency selection assistance information sent by the V2X transmitting device to the base station includes at least one of the following:

[0166] Logical channel identifier; logical channel group identifier; target identifier or target index number; QoS information; number of carrier frequencies; multi-carrier frequency indication information; wherein the multi-carrier frequency indication information is used to indicate whether multi-carrier frequency transmission, or multi-carrier frequency data split transmission, or multi-carrier frequency data duplication transmission, or multi-carrier frequency data split and data duplication transmission are used; V2X carrier frequencies (e.g., the initial candidate carrier frequency set mentioned above);

[0167] Synchronize timed information;

[0168] The synchronization timing information includes one or a combination of the following:

[0169] Synchronization reference types include: UE, GNSS, and base station;

[0170] The coverage status of the synchronization source indicates whether the synchronization source is within or outside the coverage area;

[0171] The absolute timing value of the synchronization source.

[0172] The carrier frequency selection control information sent by the base station to the V2X transmitting equipment includes at least one of the following:

[0173] The base station can send carrier frequency selection control information to the UE via system messages or RRC proprietary signaling. The carrier frequency selection control information includes one or a combination of the following:

[0174] 1. Carrier frequency list:

[0175] 1) The set of valid candidate carrier frequencies (also known as the list of available carrier frequencies) after filtering based on the CBR results;

[0176] 2) The set of valid candidate carrier frequencies sorted according to the CBR results;

[0177] 2. Number of carrier frequencies (the number of carrier frequencies required or the maximum number of carrier frequencies that can be used);

[0178] 3. Logical channel identifier; 4. Logical channel group identifier; 5. Target identifier or target index number;

[0179] 6. Multi-carrier frequency indication information, used to indicate whether multi-carrier frequency transmission is used; 7. Data offloading ratio of carrier frequency; 8. Resource pool information;

[0180] 9. Used to determine whether to use PC5 multi-carrier transmission:

[0181] 1) Priority threshold value. For example, if the PPPP value of a data packet is greater than the priority threshold value, the PC5CA function will not be used; if the PPPP value of a data packet is less than the priority threshold value, the PC5CA function can be used, including data split and data duplication.

[0182] 2) Buffer size threshold; 3) Data rate threshold; 4) Delay budget threshold; 5) Reliability threshold; 6) Reliability and delay budget thresholds; 7) Buffer size and delay budget thresholds;

[0183] 10. Information used to determine whether to use PC5 multi-carrier and / or the number of carriers:

[0184] 1) Buffer size range and corresponding number of carrier frequencies;

[0185] 2) Data rate range and corresponding number of carrier frequencies;

[0186] 3) Reliability range and corresponding number of carrier frequencies;

[0187] 4) Packet delay budget range and buffer size range and the corresponding number of carrier frequencies;

[0188] 5) Priority and corresponding number of carrier frequencies can be the number of carrier frequencies corresponding to the PPPP value / range;

[0189] 11. Information used to determine whether a carrier frequency is selectable for transmission:

[0190] 1) CBR threshold; 2) CBR threshold and corresponding priority; 3) CBR threshold and corresponding data rate; 4) CBR threshold and corresponding reliability; 5) CBR threshold and corresponding packet delay budget.

[0191] This embodiment also provides a method for sending V2X service data, see [link to documentation]. Figure 3 As shown, it includes:

[0192] With the solution provided in this embodiment, when the V2X sender needs to use multiple carrier frequencies to transmit V2X service data, the V2X sender device can obtain an initial candidate carrier frequency set for the V2X service data based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency. Then, it can use carrier frequency selection information to select carrier frequencies that meet the conditions from the initial candidate carrier frequency set to form an effective candidate carrier frequency set. Finally, it can select at least two carrier frequencies from the obtained effective candidate carrier frequency set as the transmission carrier frequencies for the V2X service data to transmit the V2X service data, thereby achieving reliable and effective selection and matching of multiple carrier frequencies.

[0193] Example 3:

[0194] This embodiment provides a PC5 carrier frequency selection device, which can be installed in a V2X transmitter device, and the functions of its various modules can be implemented by the processor of the V2X transmitter device. See also Figure 4 As shown, the PC5 carrier frequency selection device includes:

[0195] The initial selection module 401 is used to obtain an initial candidate carrier frequency set for the V2X service data based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency.

[0196] The carrier frequency determination module 402 is used to select the transmission carrier frequency of the V2X service data from the initial candidate carrier frequency set according to the carrier frequency selection information; the specific selection method is the same as the selection method shown in the above embodiment, and will not be repeated here.

[0197] This embodiment also provides a V2X transmitting device, which may be an in-vehicle terminal or a user terminal, and this V2X transmitting device also functions as a receiving device. See [link to documentation]. Figure 5 As shown, the V2X transmitting device in this embodiment includes a first processor 501, a first memory 502, and a first communication bus 503;

[0198] The first communication bus 503 is used to realize the connection and communication between the first processor 501 and the first memory 502;

[0199] The first processor 501 is used to execute one or more first programs stored in the first memory 502 to implement the steps of the PC5 carrier frequency selection method as described in Embodiment 1.

[0200] This embodiment also provides a computer storage medium that stores one or more first programs, which are executed by one or more processors to implement the steps of the PC5 carrier frequency selection method as described in Embodiment 1.

[0201] The embodiment also provides a PC5 carrier frequency selection device that can be installed on a base station, see [link to documentation]. Figure 6 As shown, it includes:

[0202] The information receiving module 601 is used to receive carrier frequency selection assistance information sent by the V2X transmitting device. The carrier frequency selection assistance information includes an initial candidate carrier frequency set of the V2X service data obtained according to the service identifier of the V2X service data and the service identifier-carrier frequency mapping relationship.

[0203] The configuration processing module 602 is used to send carrier frequency selection control information to the V2X transmitting device. Specifically, it can send an RRC connection reconfiguration message to the V2X transmitting device. This RRC connection reconfiguration message includes a set of valid candidate carrier frequencies obtained after deleting carrier frequencies that do not meet the conditions from the initial candidate carrier frequency set. The method by which the configuration processing module 602 selects carrier frequencies that meet the conditions from the initial candidate carrier frequency set using the carrier frequency selection information is the same as the selection method shown in the above embodiment, and will not be repeated here.

[0204] This embodiment also provides a base station. See [link to documentation]. Figure 7 As shown, the base station in this embodiment includes a second processor 701, a second memory 702, and a second communication bus 703;

[0205] The second communication bus 703 is used to realize the connection and communication between the second processor 701 and the second memory 702;

[0206] The second processor 701 is used to execute one or more second programs stored in the second memory 702 to implement the steps of the PC7 carrier frequency selection method as described in Embodiment 2.

[0207] This embodiment also provides a computer storage medium that stores one or more programs, which are executed by one or more processors to implement the steps of the PC7 carrier frequency selection method as described in Embodiment 1 or Embodiment 2.

[0208] To facilitate understanding of the present invention, this embodiment uses the V2X transmitting device as a UE as an example, and describes the UE in RRC idle state and using mode 4.

[0209] For the carrier frequency selection method of the RRC idle mode 4 UE, please refer to [link / reference]. Figure 8 As shown, it includes:

[0210] S801: After the UE's higher layer generates a V2X message (i.e., V2X service data, or V2X data packet), for each V2X message, the UE's higher layer obtains candidate carrier frequency set 1 (i.e., initial candidate carrier frequency set) based on the service identifier of the V2X message and the mapping relationship between the service identifier and the carrier frequency, and sends it to the AS layer.

[0211] Optionally, each V2X message may carry at least one of the following when it is passed from the UE's higher layer to the UE's AS (Access Stratum) layer: its corresponding service identifier, target identifier, priority (PPPP), and carrier frequency set 1 (containing one or more V2X carrier frequency point information).

[0212] S802: Optional, when each V2X message arrives at the AS layer, the UE's AS layer maps it to the corresponding PC5 logical channel based on the service-related information of the V2X message.

[0213] If the V2X message does not have a corresponding logical channel, a new logical channel is established. Service-related information includes one or a combination of the following: V2X service identifier, target identifier, PPP priority, reliability requirement, data rate requirement, and packet delay budget. For example, a V2X message with service identifier 1 and priority 1 is mapped to logical channel 1, and a V2X message with service identifier 1 and priority 2 is mapped to logical channel 2.

[0214] In this step, if the UE receives the mapping relationship between PPPP and reliability requirements from the base station, or obtains the mapping relationship through pre-configuration, or obtains the mapping relationship from the V2X control function or V2X application server, the UE can calculate the reliability requirements of the data packet based on the PPPP of the data packet and the mapping relationship between PPPP and reliability requirements. Alternatively, the UE can obtain the V2X message and its corresponding reliability requirements from a higher layer. Optionally, the UE can determine whether to use multi-carrier data duplication for transmission based on the reliability requirements of the data packet. The UE can compare the obtained reliability requirements with a pre-configured reliability threshold value, obtained from the V2X control function or V2X application server, or obtained from the base station; or obtain the mapping relationship between the reliability requirement range and the number of carrier frequencies from the base station, and match the obtained reliability requirements with the mapping relationship between the reliability requirement range and the number of carrier frequencies; thereby determining whether to use multi-carrier data duplication for transmission. Optionally, if multi-carrier data duplication is required for transmission, the UE establishes multiple logical channels for transmitting the data packet. If multi-carrier transmission is required at this stage, subsequent checks on whether multi-carrier transmission is needed can be skipped. If this check is not performed here, multi-carrier transmission checks can be performed later.

[0215] S803: The UE determines the set of candidate carrier frequencies for each PC5 logical channel (or each V2X data packet).

[0216] For example, candidate carrier set 1 is determined based on the carrier frequency set corresponding to the V2X message obtained from the higher layers. Optionally, the AS layer obtains the intersection of the V2X carrier frequency set supported by the base station and candidate carrier frequency set 1, and uses this intersection as candidate carrier frequency set 2. Optionally, if the V2X carrier frequency set supported by the base station has no intersection with candidate carrier frequency set 1, and no suitable cell is detected on the V2X carrier frequency pre-configured in the UE, the UE considers itself to be in a state of no coverage, and obtains candidate carrier frequency set 2 based on the intersection between candidate carrier frequency set 1 and the pre-configured V2X carrier frequency for no coverage for subsequent carrier frequency selection.

[0217] S804: Optionally, the UE selects multiple carrier frequencies with synchronized timing from candidate carrier frequency set 2 based on the synchronization reference timing information on the carrier frequency where the resource pool is located, and deletes the other carrier frequencies in candidate carrier frequency set 2, forming candidate carrier frequency set 3. The synchronization reference timing information includes one or a combination of the following: synchronization reference type, coverage status of the synchronization source (in-coverage or out-of-coverage); absolute timing value of the synchronization source. The synchronization reference type is the synchronization reference type selected by the UE's physical layer. This step can also be omitted.

[0218] S805: The UE performs CBR measurement on the resource pool of V2X carriers in candidate carrier set 2 or candidate carrier set 3 (when step S804 is not performed), or the UE performs CBR measurement on the V2X resource pools of multiple carriers in candidate carrier set 2 that are synchronized and timed.

[0219] Specifically, the UE can obtain V2X resource pool information on candidate carrier frequencies from the base station via system messages, or obtain such information through pre-configuration. The UE can obtain one or more CBR threshold values ​​from the base station via system messages to determine whether the carrier frequency containing the V2X resource pool is available for PC5 transmission, or obtain one or more CBR threshold values ​​through pre-configuration. Furthermore, the configuration information obtained by the UE can also be multiple CBR threshold values ​​corresponding to different QoS parameters, V2X service types, carrier frequencies, or resource pools. Specifically, QoS parameters can be one or a combination of the following: priority, data rate, reliability, and packet delay budget. For example, the UE determines the CBR threshold value corresponding to the logical channel based on the service type or QoS parameters corresponding to the logical channel to determine whether the V2X carrier frequency is available for data transmission on that logical channel. Specifically, the UE determines whether the carrier frequency containing the measured resource pool is usable for transmission based on the CBR measurement results of the V2X resource pool on each carrier frequency. For example, if the CBR measurement result of the resource pool is higher than the corresponding CBR threshold, the UE considers the carrier frequency unusable for transmission; if the CBR measurement result of the resource pool is lower than the corresponding CBR threshold, the UE considers the carrier frequency usable for transmission. The UE then filters out candidate carrier frequency set 4 based on the CBR measurement process of the resource pools of V2X carrier frequencies in candidate carrier frequency set 2 or candidate carrier frequency set 3, thus excluding carrier frequencies unusable for transmission. Optionally, the UE sorts the frequency points in candidate carrier frequency set 4 according to their CBR measurement values. For example, if the carrier frequencies are sorted from smallest to largest CBR measurement value, the frequency point with the smallest CBR measurement value is ranked first, and so on.

[0220] S806: The UE selects carrier frequencies that can be transmitted simultaneously within its capability range from the candidate carrier frequency set 4 based on its own PC5CA capability information to form the candidate carrier frequency set 5.

[0221] Specifically, the UE selects the maximum number of carrier frequencies that can simultaneously perform PC5 transmission within its capability range from the candidate carrier frequency set 4, forming the candidate carrier frequency set 5, based on its own PC5CA transmission capability information. Specifically, the UE's PC5CA transmission capability information includes one or a combination of the following: 1) band combination information for simultaneous PC5 transmission; 2) band combination information for simultaneous PC5 / Uu transmission; 3) number of transmission links (Txchain).

[0222] S807: The UE's AS layer determines whether multi-carrier transmission is required, and if necessary, determines the number of carriers to be used for transmission and selects a set of carriers for transmission from the candidate carrier set 5.

[0223] In this example, the UE's AS layer can determine whether multiple carrier frequencies are needed for PC5 data transmission via data splitting and / or data duplication based on one or a combination of the following information. If needed, the number of carrier frequencies required for transmission is further determined, and a set of carrier frequencies for transmission is selected from the candidate carrier frequency set 5:

[0224] 1) Data packet reliability requirements: Higher layers can carry data packet reliability requirement information when transmitting data packets to the AS layer. Alternatively, the UE can obtain the mapping relationship between PPP and reliability requirements from the base station, or obtain the mapping relationship between PPP and reliability requirements through pre-configuration, and map the reliability requirements based on the data packet's PPP value. Alternatively, a new PC5QoS parameter can be defined, and the higher layers can carry the data packet's QoS parameter when transmitting data packets to the AS layer. The UE can then deduce the data packet's reliability requirements based on this newly defined QoS parameter.

[0225] 2) Reliability threshold value,

[0226] 3) Reliability range and corresponding number of carrier frequencies;

[0227] 4) Packet delay budget; when a higher layer transmits a packet to the AS layer, it can also carry the packet delay budget requirement information. Alternatively, the UE can obtain the mapping relationship between PPPP and packet delay budget requirements, and map the packet delay budget requirement based on the PPPP value of the packet. The UE can obtain the mapping relationship between PPPP and packet delay budget requirements from the base station, or obtain it through pre-configuration.

[0228] 5) Packet delay budget threshold;

[0229] 6) Packet delay budget range and corresponding number of carrier frequencies;

[0230] 7) Data packet priority; when a higher layer transmits a data packet to the AS layer, it can also carry the priority information of the data packet. The priority can be represented by the PPP value.

[0231] 8) Priority threshold;

[0232] 9) Priority and corresponding number of carrier frequencies;

[0233] 10) Data rate requirement of data packets; when higher layers transmit data packets to the AS layer, they can also carry the data rate requirement information of the data packets. Alternatively, the UE can obtain the mapping relationship between PPPP and data rate requirement from the base station, or obtain the mapping relationship between PPPP and data rate requirement through pre-configuration, and map the data rate requirement according to the PPPP value of the data packet. Alternatively, a new PC5QoS parameter can be defined, and the QoS parameter of the data packet can be carried by the higher layers when transmitting data packets to the AS layer. The UE can deduce the data rate requirement of the data packet according to the newly defined QoS parameter.

[0234] 11) Data rate threshold;

[0235] 12) Data rate range and corresponding number of carrier frequencies;

[0236] 13) Current buffer size;

[0237] 14) Buffer size threshold;

[0238] 15) Buffer size range and corresponding number of carrier frequencies;

[0239] 16) Packet delay budget range and buffer size range and the corresponding number of carrier frequencies;

[0240] Optionally, the UE can determine whether to use multiple carriers for PC5 data transmission via data split and / or data duplication using the following methods:

[0241] For example, if the UE receives priority threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the priority of the data to be transmitted and the priority threshold information. For example, if the priority value of the data to be transmitted (e.g., PPPP) is less than the configured priority threshold value, then multiple carriers can be used for PC5 data transmission.

[0242] If the UE receives Data rate threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the Data rate requirement for the data to be transmitted and the Data rate threshold information. For example, if the Data rate requirement for the data to be transmitted is greater than the configured Data rate threshold, then multiple carriers can be used for PC5 data transmission.

[0243] If the UE receives the buffer size threshold information from the base station, the UE determines whether multiple carrier frequencies can be used for PC5 data transmission based on the current logical channel's buffer size and the buffer size threshold information. For example, if the current logical channel's buffer size is greater than the configured buffer size threshold, then multiple carrier frequencies can be used for PC5 data transmission.

[0244] If the UE receives reliability threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the reliability requirements of the data to be transmitted and the reliability threshold information. For example, if the reliability requirements of the data to be transmitted are higher than the configured reliability threshold, then multiple carriers can be used for PC5 data transmission.

[0245] If the UE receives packet delay budget threshold information from the base station, the UE determines whether to use multiple carrier frequencies for PC5 data transmission based on the packet delay budget of the data to be transmitted and the packet delay budget threshold information. For example, if the packet delay budget of the data to be transmitted is less than the configured packet delay budget threshold, then multiple carrier frequencies can be used for PC5 data transmission.

[0246] In this embodiment, the determination of the number of carrier frequencies used for transmission and the selection of the carrier frequency set for transmission from the candidate carrier frequency set 5 can be seen in the following examples.

[0247] Example 1: Determine based on packet delay budget and buffer size

[0248] The UE can first select carrier frequency 1, which is ranked first in the candidate carrier frequency set 5, based on the carrier frequency list sorted according to the CBR measurement results in S806. If the available resources in the resource pool of this carrier frequency can meet the data transmission requirements in the buffer within the delay budget, then only carrier frequency 1 is used for data transmission. If it cannot meet the requirements, then carrier frequency 2, which is ranked second, is added for transmission. If the available resources in the resource pools of carrier frequency 1 and 2 can meet the data transmission requirements in the buffer within the delay budget, then carrier frequency 1 and carrier frequency 2 are used for data transmission. If it cannot meet the requirements, then carrier frequency selection continues, and carrier frequency 3, which is ranked third, is added. Subsequent operations are similar to the above.

[0249] Example 2: Determine based on the configured buffer size range, packet delay budget, and corresponding number of carrier frequencies.

[0250] The UE obtains the mapping relationship between the buffer size range and packet delay budget to the number of carrier frequencies from the base station. Based on the current buffer size and packet delay budget, the UE determines the number of carrier frequencies to be used and selects a carrier frequency for transmission from the candidate carrier frequency set 5. For example, the base station can configure the UE with a buffer size of 200-400 bytes and a packet delay budget of 50ms, corresponding to 2 carrier frequencies; and a buffer size of 200-400 bytes and a packet delay budget of 100ms, corresponding to 1 carrier frequency. In this example scenario, the UE needs to re-determine the number of carrier frequencies to be used each time the buffer size range changes and select a carrier frequency for transmission from the candidate carrier frequency set 5. Then, the UE performs a resource selection process within the V2X resource pool of the selected carrier frequency for transmission to select the specific time-frequency domain resources for transmission.

[0251] Example 3: Determine based on the configured buffer size range and the corresponding number of carrier frequencies.

[0252] The base station can configure the number of available carrier frequencies corresponding to the buffer size range for the UE, or the UE can obtain this information through pre-configuration. The UE determines the number of carrier frequencies required for the logical channel based on the current logical channel's buffer size and this mapping. For example, if the configuration is that a buffer size of 0-200 bytes corresponds to 1 carrier frequency, and a buffer size of 200-400 bytes corresponds to 2 carrier frequencies, then if the current logical channel's buffer size is 350 bytes, the UE determines that 2 carrier frequencies are required for transmission. In this example scenario, once the range of the logical channel's buffer size changes, the number of carrier frequencies required is re-determined, and carrier frequencies for transmission are selected from the candidate carrier frequency set 5. Then, the UE performs a resource selection process within the V2X resource pool of the selected carrier frequencies to choose specific time-frequency domain resources for transmission.

[0253] Example 4: Determine based on the configured data rate range and the corresponding number of carrier frequencies.

[0254] The base station can configure a mapping relationship between the data rate range and the number of carrier frequencies for the UE. The UE determines the number of carrier frequencies to be used based on the data rate requirement of the V2X data to be transmitted and this mapping relationship. The UE selects a carrier frequency for transmission from the candidate carrier frequency set 5. When the higher layers transmit data packets to the AS layer, they can also carry the data rate requirement information of the data packets. Alternatively, the UE can obtain the mapping relationship between PPPP and data rate requirement from the base station, or obtain the mapping relationship between PPPP and data rate requirement through pre-configuration, and map the data rate requirement based on the PPPP value of the data packet. Alternatively, a new PC5QoS parameter can be defined, and the higher layers can carry the QoS parameter of the data packet when transmitting data packets to the AS layer. The UE can deduce the data rate requirement of the data packet based on the newly defined QoS parameter. In this example case, once the range of the data rate requirement of the logical channel changes, the number of carrier frequencies to be used is re-determined, and a carrier frequency for transmission is selected from the candidate carrier frequency set 5. Then, the UE performs a resource selection process in the V2X resource pool within the selected carrier frequency for transmission to select the specific time-frequency domain resource for transmission.

[0255] Example 5: Determine based on the configured reliability range and the corresponding number of carrier frequencies.

[0256] The base station can configure a mapping relationship between reliability range and the number of carrier frequencies for the UE. The UE determines the number of carrier frequencies to be used based on the reliability requirements of the V2X service and this mapping relationship. Then, the UE selects a carrier frequency for transmission from the candidate carrier frequency set 5. When the higher layers transmit data packets to the AS layer, they can also carry the reliability requirement information of the data packets. Alternatively, the UE can obtain the mapping relationship between PPPP and reliability requirements from the base station, or obtain the mapping relationship between PPPP and reliability requirements through pre-configuration, and map the reliability requirements based on the PPPP value of the data packet. Alternatively, a new PC5QoS parameter can be defined, and the higher layers can carry the QoS parameter of the data packet when transmitting data packets to the AS layer. The UE can deduce the reliability requirements of the data packet based on the newly defined QoS parameter. In this example scenario, once the range of the reliability requirements of the logical channel changes, the number of carrier frequencies to be used is re-determined, and a carrier frequency for transmission is selected from the candidate carrier frequency set 5. Then, the UE performs a resource selection process within the V2X resource pool of the selected carrier frequency for transmission to select the specific time-frequency domain resources for transmission.

[0257] Example 6: Carrier frequency selection under SPS data splitting method

[0258] For V2X service SPS data streams, the UE can determine the number of resource blocks (RBs), retransmission counts, and MCS (Modulation and Coding Scheme) selectable on a given frequency based on the CBR measurement results of the resource pool at that frequency and the PPPP corresponding to the highest priority logical channel. This determines the amount of resources that can be transmitted on a single carrier frequency. Then, based on the data packet size, it determines whether data splitting is necessary for multi-carrier data transmission. If so, it further determines how many carrier frequencies the data packets need to be split onto. After determining the number of carrier frequencies to split, the UE determines the reservation interval and HARQ (Hybrid Automatic Repeat reQuest) retransmission count for each carrier frequency, and then performs resource selection and initiates SPS transmission on each carrier frequency.

[0259] Alternatively, the UE can determine whether data splitting is necessary for multi-carrier data transmission based on the CBR measurement results of the resource pool on the frequency point and the period of the data packets. If necessary, it can further determine how many carrier frequencies the data packets need to be split onto. After determining the number of carrier frequencies to be split, the UE determines the reservation interval and HARQ retransmission count for each carrier frequency, and then performs resource selection and starts SPS transmission on each carrier frequency.

[0260] Optionally, each carrier frequency uses an independent SL process, and each SL process corresponds to an independent SL_RESOURCE_RESELECTION_COUNTER.

[0261] It should be understood that the above Figure 8 The steps shown can be freely combined and their timing can be adjusted.

[0262] Example 4:

[0263] To facilitate understanding of the present invention, this embodiment uses the V2X transmitting device as a UE as an example, and describes the UE as being in RRC connection state and using mode 4.

[0264] For the carrier frequency selection method of mode 4 UE in RRC connected state, please refer to [link / reference]. Figure 9 As shown, it includes:

[0265] S901: The UE sends an RRC message to the base station when the conditions are met (e.g., there is V2X service data to be sent).

[0266] The RRC message sent by the UE can be a sidelink UE information message or a UE assistance information message, which includes the frequency points requesting V2X sidelink transmission resources and the corresponding target ID list (v2x-DestinationInfoList, through which the base station can deduce the corresponding V2X service identifier). The V2X carrier frequencies included in the RRC message sent by the UE are either candidate carrier frequency set 1 (i.e., the initial candidate carrier frequency set) obtained by the UE based on the service identifier of the data to be transmitted and the mapping relationship between the service identifier and the carrier frequency, or the intersection of candidate carrier frequency set 1 obtained by the UE based on the service identifier of the data to be transmitted and the V2X carrier frequency set supported by the base station (e.g., including the serving carrier frequency and the V2X inter-frequency points sent by the base station to the UE), i.e., candidate carrier frequency set 2. Optionally, the RRC message includes the logical channel identifier and corresponding QoS information of the requested resources, or the target identifier and corresponding QoS information, or the logical channel group identifier and corresponding QoS information, that is, it includes the QoS information corresponding to the data to be transmitted. Optionally, if V2X data with the same target ID contains multiple QoS requirements, the PC5 signaling only includes the highest QoS requirement information among these requirements; similarly, if the same logical channel group can be used to transmit data with multiple QoS requirements, the PC5 signaling only includes the highest QoS requirement information among these requirements. Specifically, the QoS information includes one or a combination of the following: data rate requirement, reliability requirement, priority, and packet delay budget. The reliability requirement can be reliability level information. Optionally, the RRC message includes synchronization timing information for each carrier frequency.

[0267] As shown in the analysis of Embodiment 1 above, the carrier frequency selection assistance information sent by the UE to the base station includes at least one of the following:

[0268] Logical channel identifier;

[0269] Logical channel group identifier;

[0270] Target identifier;

[0271] QoS information;

[0272] Number of carrier frequencies;

[0273] Multi-carrier frequency indication information; wherein the multi-carrier frequency indication information is used to indicate whether multi-carrier frequency transmission is used, or whether multi-carrier frequency data split transmission is used, or whether multi-carrier frequency data duplication transmission is used, or whether multi-carrier frequency data split and data duplication transmission is used.

[0274] V2X carrier frequency;

[0275] Synchronization timing information for each carrier; including one or a combination of the following: synchronization reference type (UE, GNSS, base station); coverage status of the synchronization source (indicating whether the synchronization source is within or outside coverage); absolute timing value of the synchronization source;

[0276] S902: The eNB sends RRC Connection Reconfiguration information to the UE, which includes resource allocation mode indication information (mode 4) and corresponding configuration information.

[0277] The base station can determine the UE's resource allocation mode based on the information in the RRC message received from the UE, generate corresponding resource allocation mode indication information, and send corresponding configuration information to the UE. Optionally, the base station can filter out timing-aligned carrier frequencies as a V2X carrier frequency set based on the synchronization timing information of each carrier frequency reported by the UE. Optionally, if the base station configures the UE to use mode4 resource allocation, the base station can filter out V2X carrier frequencies that can be used for UE transmission based on the CBR measurement results of each carrier frequency V2X resource pool in candidate carrier frequency set 1 or candidate carrier frequency set 2 reported by the UE (including the UE requesting resources or other UEs) to obtain candidate carrier frequency set 3. The V2X carrier frequency set sent by the base station to the UE can be sorted according to the CBR value of the resource pool on each carrier frequency, for example, the carrier frequency / resource pool with the lowest CBR value is ranked first.

[0278] Optionally, referring to Embodiment 1 above, the base station can also determine whether to use multi-carrier transmission, or determine the number of carriers, or determine the carrier data offloading ratio configuration information based on the QoS information reported by the UE. Of course, these processes can also be performed by the UE itself.

[0279] For example, in this step, the base station can determine whether to use multi-carrier data duplication and / or data split methods for data packets corresponding to the logical channel, logical channel group, or target identifier based on the QoS information reported by the UE. For example, the base station can calculate the reliability requirement based on the PPP value reported by the UE and the mapping relationship between PPP and reliability requirements, and then determine whether to use multi-carrier data duplication for transmission based on the reliability requirement. Alternatively, the base station can also determine whether to use multi-carrier data duplication for transmission based on the reliability requirement information reported by the UE. Alternatively, the base station can calculate the data rate requirement based on the data rate reported by the UE and the mapping relationship between PPP and data rate, and then determine whether to use multi-carrier data split for transmission based on the data rate requirement. Alternatively, the base station can also determine whether to use multi-carrier data split for transmission based on the data rate requirement information reported by the UE.

[0280] Optionally, if the base station determines that the UE needs to use multi-carrier data duplication and / or data split for transmission, it sends multi-carrier frequency indication information to the UE.

[0281] Therefore, in this embodiment, the carrier frequency selection control information sent by the base station to the UE via system messages or RRC proprietary signaling may include at least one of the following:

[0282] 1. Carrier frequency list:

[0283] 1) The carrier frequency used for transmission; or,

[0284] 2) The set of valid candidate carrier frequencies filtered based on the CBR results; or,

[0285] 3) The set of valid candidate carrier frequencies sorted according to the CBR results (e.g., the sorted set of candidate carrier frequencies 3);

[0286] 2. Number of carrier frequencies: Indicates the number of carrier frequencies required or the maximum number of carrier frequencies that can be used;

[0287] 3. Logical channel identifier;

[0288] 4. Logical channel group identifier;

[0289] 5. Target identifier or target index number;

[0290] 6. Multi-carrier frequency indication information, used to indicate whether multi-carrier frequency transmission is used;

[0291] 7. Data offloading ratio of the carrier frequency;

[0292] 8. Resource pool information;

[0293] 9. Information used to determine whether to use PC5 multi-carrier transmission:

[0294] 1) Priority threshold value. For example, if the PPPP value of a data packet is greater than the priority threshold value, the PC5CA function will not be used; if the PPPP value of a data packet is less than the priority threshold value, the PC5CA function can be used, including data split and data duplication.

[0295] 2) Buffer size threshold; 3) Data rate threshold; 4) Delay budget threshold; 5) Reliability threshold; 6) Reliability and delay budget thresholds; 7) Buffer size and delay budget thresholds;

[0296] 10. Information used to determine whether to use PC5 multi-carrier and / or the number of carriers:

[0297] 1) Buffer size range and corresponding number of carrier frequencies;

[0298] 2) Data rate range and corresponding number of carrier frequencies;

[0299] 3) Reliability range and corresponding number of carrier frequencies;

[0300] 4) Packet delay budget range and buffer size range and the corresponding number of carrier frequencies;

[0301] 5) Priority and corresponding number of carrier frequencies can be the number of carrier frequencies corresponding to the PPPP value / range;

[0302] 11. Information used to determine whether a carrier frequency is selectable for transmission:

[0303] 1) CBR threshold; 2) CBR threshold and corresponding priority; 3) CBR threshold and corresponding data rate; 4) CBR threshold and corresponding reliability; 5) CBR threshold and corresponding packet delay budget; 6) CBR threshold and corresponding frequency; 7) CBR threshold and corresponding resource pool.

[0304] S903: The UE uses the carrier frequencies in the candidate carrier frequency set 3 obtained from the base station to perform PC5 data transmission. At this time, the base station performs the above-mentioned carrier frequency selection process; or, the UE performs carrier frequency selection in the candidate carrier frequency set 3 received from the base station. At this time, the UE performs carrier frequency selection.

[0305] If the resource configuration information received by the UE from the base station includes a logical channel identifier and a corresponding carrier frequency list, then the UE will perform subsequent carrier frequency selection (including the number of carrier frequencies and the specific carrier frequencies) and resource selection for the data in the logical channel in the corresponding carrier frequency list.

[0306] If the resource configuration information received by the UE from the base station includes a logical channel group identifier and a corresponding carrier frequency list, then the UE will perform subsequent carrier frequency selection and resource selection for the data in the logical channel group in the corresponding carrier frequency list.

[0307] If the resource configuration information received by the UE from the base station includes a target identifier and a corresponding carrier frequency list, the UE will perform subsequent carrier frequency selection and resource selection based on the target identifier in the corresponding carrier frequency list.

[0308] Optionally, for each logical channel, the UE performs CBR measurement on the resource pool of V2X carriers in the V2X carrier list (i.e., candidate carrier set 3) configured by the base station. Specifically, the resource pool information of the V2X carriers is obtained by the UE from the base station.

[0309] Optionally, the UE can select the timing-aligned carrier frequencies as the V2X carrier frequency set based on the synchronization timing information on each carrier frequency.

[0310] Optionally, if the UE obtains a CBR threshold value from the base station, the CBR threshold value is used to determine whether the carrier frequency where the V2X resource pool is located can be used for PC5 transmission. If the UE obtains a CBR threshold value and the corresponding carrier frequency from the base station, the UE uses the corresponding CBR threshold value on that carrier frequency; if the UE obtains a CBR threshold value and the corresponding resource pool from the base station, the UE uses the corresponding CBR threshold value on that resource pool; if the UE obtains a CBR threshold value and the corresponding priority from the base station, the UE determines its corresponding CBR threshold value based on the priority of the data to be transmitted or the priority of the data transmitted on that logical channel. If the UE obtains a CBR threshold value and the corresponding data rate requirement from the base station, the UE determines its corresponding CBR threshold value based on the data rate requirement of the data to be transmitted or the data rate requirement of the data transmitted on that logical channel. If the UE obtains a CBR threshold value and the corresponding reliability from the base station, the UE determines its corresponding CBR threshold value based on the reliability requirement of the data to be transmitted or the reliability requirement of the data transmitted on that logical channel. If the UE obtains the CBR threshold value and the corresponding packet delay budget requirement from the base station, the UE determines its corresponding CBR threshold value based on the packet delay budget requirement of the data to be transmitted or the packet delay budget requirement of the data transmitted on the logical channel.

[0311] The UE determines whether a carrier frequency containing a measured resource pool is usable for transmission based on the CBR measurement results of the V2X resource pools on each carrier frequency. For example, if the CBR measurement result of the resource pool is higher than the corresponding CBR threshold, the UE considers the carrier frequency unusable for transmission; if the CBR measurement result of the resource pool is lower than the corresponding CBR threshold, the UE considers the carrier frequency usable for transmission. The UE filters candidate carrier frequency set 4 based on the CBR measurement process of the resource pools in the V2X list configured for the base station, thus excluding carrier frequencies unusable for transmission. Optionally, the UE sorts the frequency points in candidate carrier frequency set 4 according to their CBR measurement values. For example, if the carrier frequencies are sorted from smallest to largest CBR measurement value, the frequency point with the smallest CBR measurement value is ranked first, and so on.

[0312] S904: Determine whether to use multiple carrier frequencies for PC5 data transmission.

[0313] Optionally, if the base station generates the aforementioned multi-carrier transmission configuration information, the UE can determine whether to use multiple carriers for PC5 data transmission based on the configuration information received from the base station, including data splitting and / or data duplication.

[0314] 1) If the configuration information received by the UE from the base station includes a logical channel identifier and the corresponding multi-carrier frequency indication information, the UE determines whether the corresponding logical channel uses a multi-carrier frequency for PC5 data transmission based on the multi-carrier frequency indication information.

[0315] 2) If the configuration information received by the UE from the base station includes a logical channel group identifier and the corresponding multi-carrier frequency indication information, then determine whether the corresponding logical channel group uses multi-carrier frequency for PC5 data transmission based on the multi-carrier frequency indication information;

[0316] 3) If the configuration information received by the UE from the base station includes the target identifier and the corresponding multi-carrier frequency indication information, the UE determines whether the corresponding target identifier data should use the multi-carrier frequency for PC5 data transmission based on the multi-carrier frequency indication information.

[0317] The UE can also determine whether multi-carrier transmission is required based on the corresponding threshold information obtained from the base station, including but not limited to:

[0318] 4) If the UE receives priority threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the priority of the data to be transmitted and the priority threshold information. For example, if the priority value of the data to be transmitted (e.g., PPPP) is less than the configured priority threshold value, then multiple carriers can be used for PC5 data transmission.

[0319] 5) If the UE receives data rate threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the data rate requirement for the data to be transmitted and the data rate threshold information. For example, if the data rate requirement for the data to be transmitted is greater than the configured data rate threshold, then multiple carriers can be used for PC5 data transmission;

[0320] 6) If the UE receives buffer size threshold information from the base station, the UE determines whether multiple carrier frequencies can be used for PC5 data transmission based on the current logical channel's buffer size and the buffer size threshold information. For example, if the current logical channel's buffer size is greater than the configured buffer size threshold, multiple carrier frequencies can be used for PC5 data transmission.

[0321] 7) If the UE receives reliability threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the reliability requirements of the data to be transmitted and the reliability threshold information. For example, if the reliability requirements of the data to be transmitted are higher than the configured reliability threshold, then multiple carriers can be used for PC5 data transmission.

[0322] 8) If the UE receives packet delay budget threshold information from the base station, the UE determines whether multiple carrier frequencies can be used for PC5 data transmission based on the packet delay budget of the data to be transmitted and the packet delay budget threshold information. For example, if the packet delay budget of the data to be transmitted is less than the configured packet delay budget threshold, multiple carrier frequencies can be used for PC5 data transmission.

[0323] S905: Determine the number of carrier frequencies.

[0324] Optionally, the UE can determine the number of carrier frequencies to be used based on the service identifier information or QoS information of the data to be transmitted, and select a certain number of carrier frequencies from candidate carrier frequency set 3 or candidate carrier frequency set 4 received from the base station. If the base station performs the determination of the number of carrier frequencies, i.e., the generation of corresponding configuration information, the UE can obtain the carrier frequency configuration information from the base station, and then select a certain number of carrier frequencies from candidate carrier frequency set 3 or candidate carrier frequency set 4 received from the base station according to the received carrier frequency configuration information. Specifically, this can be divided into the following cases:

[0325] 1) If the resource configuration information received by the UE from the base station includes a logical channel identifier and the corresponding number of carrier frequencies, then the UE selects the corresponding number of carrier frequencies for transmission of data in the logical channel;

[0326] 2) If the resource configuration information received by the UE from the base station includes the logical channel group identifier and the corresponding number of carrier frequencies, then the UE selects the corresponding number of carrier frequencies for transmission of data in the logical channel group.

[0327] 3) If the resource configuration information received by the UE from the base station includes the target identifier and the corresponding number of carrier frequencies, then the UE selects the corresponding number of carrier frequencies for transmission of the data to be sent for the same target identifier;

[0328] 4) If the resource configuration information received by the UE from the base station includes a buffer size range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies that the logical channel needs to use or the maximum number of carrier frequencies that can be used based on the current buffer size range of the logical channel and the configured mapping relationship between the buffer size range and the number of carrier frequencies.

[0329] 5) If the resource configuration information received by the UE from the base station includes a data rate range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the range of the data rate requirement of the data to be transmitted and the mapping relationship between the configured data rate requirement range and the number of carrier frequencies.

[0330] 6) If the resource configuration information received by the UE from the base station includes the reliability range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the range of the reliability requirement of the data to be transmitted and the mapping relationship between the configured reliability requirement range and the number of carrier frequencies.

[0331] 7) If the resource configuration information received by the UE from the base station includes the packet delay budget range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the range of the packet delay budget of the data to be transmitted and the mapping relationship between the configured packet delay budget range and the number of carrier frequencies.

[0332] 8) If the resource configuration information received by the UE from the base station includes the packet delay budget range and buffer size range and the corresponding number of carrier frequencies, then the UE determines the number of carrier frequencies that the logical channel needs to use or the maximum number of carrier frequencies that can be used based on the range of the packet delay budget of the data to be transmitted, the range of the current buffer size of the logical channel, and the mapping relationship between the configured packet delay budget range and buffer size range and the number of carrier frequencies.

[0333] For example, the base station can configure the number of carrier frequencies for the UE to be 200-400 bytes with a packet delay budget of 50ms, and 100ms with a packet delay budget of 100ms.

[0334] 8) If the resource configuration information received by the UE from the base station includes priority and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies that the logical channel needs to use or the maximum number of carrier frequencies that can be used based on the priority of the data transmitted by the logical channel and the configured mapping relationship between priority and number of carrier frequencies.

[0335] S906: Determine the amount of data to be transmitted on each carrier frequency.

[0336] If the UE determines that multiple carrier frequencies are needed for PC5 data transmission and has determined the carrier frequencies to be used for transmission, and the UE does not receive the data offloading ratio of the carrier frequencies from the base station, then it will determine the amount of data to be transmitted on each of the selected carrier frequencies and perform subsequent resource selection on each carrier frequency according to the sensing results.

[0337] Alternatively, if the UE determines that multiple carrier frequencies are needed for PC5 data transmission and determines the carrier frequencies to be used for transmission, and the configuration information received by the UE from the base station includes carrier frequency data offloading ratio information, then the UE calculates the amount of data to be transmitted on each carrier frequency based on the carrier frequency data offloading ratio information, and performs subsequent resource selection on each carrier frequency respectively.

[0338] Optionally, if the configuration information received by the UE from the base station includes a logical channel identifier, a carrier frequency list, and the corresponding carrier frequency data offloading ratio, then the UE uses the corresponding carrier frequency in the carrier frequency list to transmit data in the logical channel. The UE calculates the amount of data to be transmitted on each carrier frequency based on the configured data offloading ratio, and performs subsequent resource selection on each carrier frequency. For example, if the amount of data to be transmitted in logical channel 1 is 200 bytes, and it is determined that carrier frequency 1 and carrier frequency 2 will be used for transmission, and if the data offloading ratio for carrier frequency 1 is 60% and the data offloading ratio for carrier frequency 2 is 40% in the configuration information received by the UE from the base station, then the UE calculates that the amount of data that can be transmitted using carrier frequency 1 is 120 bytes, and the amount of data that can be transmitted using carrier frequency 2 is 80 bytes.

[0339] If the configuration information received by the UE from the base station includes a logical channel group identifier, a carrier frequency list, and the corresponding carrier frequency data offloading ratio, then the UE will use the corresponding carrier frequency in the carrier frequency list to transmit the data in the logical channel group, and calculate the amount of data to be transmitted on each carrier frequency according to the configured data offloading ratio of each carrier frequency, and perform subsequent resource selection on each carrier frequency respectively.

[0340] If the configuration information received by the UE from the base station includes a target identifier, a carrier frequency list, and the corresponding carrier frequency data offloading ratio, then the UE will use the corresponding carrier frequency in the carrier frequency list to transmit data for the same target identifier. The UE will also calculate the amount of data to be transmitted on each carrier frequency based on the configured data offloading ratio for each carrier frequency, and perform subsequent resource selection on each carrier frequency respectively.

[0341] It should be understood that the above Figure 9 The steps shown can be freely combined, and the order of time can be adjusted.

[0342] Example 5:

[0343] To facilitate understanding of the present invention, this embodiment uses the V2X transmitting device as a UE as an example, and describes the UE as being in RRC connection state and using mode 3.

[0344] For the transmit carrier frequency selection method of a mode 3 UE in RRC connected state, see [link to relevant documentation]. Figure 10 As shown, it includes:

[0345] S1001: The UE sends an RRC message to the base station when the conditions are met (e.g., there is V2X service data to be sent).

[0346] The RRC message sent by the UE can be a sidelink UE information message or a UE assistance information message, which includes the frequency points requesting V2X sidelink transmission resources and the corresponding target ID list (v2x-DestinationInfoList, through which the base station can deduce the corresponding V2X service identifier). The V2X carrier frequencies included in the RRC message sent by the UE are either candidate carrier frequency set 1 (i.e., the initial candidate carrier frequency set) obtained by the UE based on the service identifier of the data to be transmitted and the mapping relationship between the service identifier and the carrier frequency, or the intersection of candidate carrier frequency set 1 obtained by the UE based on the service identifier of the data to be transmitted and the V2X carrier frequency set supported by the base station (e.g., including the serving carrier frequency and the V2X inter-frequency points sent by the base station to the UE), i.e., candidate carrier frequency set 2. Optionally, the RRC message includes the logical channel identifier and corresponding QoS information of the requested resources, or the target identifier and corresponding QoS information, or the logical channel group identifier and corresponding QoS information, that is, it includes the QoS information corresponding to the data to be transmitted. Optionally, if V2X data with the same target ID contains multiple QoS requirements, the PC5 signaling only includes the highest QoS requirement information among these requirements; similarly, if the same logical channel group can be used to transmit data with multiple QoS requirements, the PC5 signaling only includes the highest QoS requirement information among these requirements. Specifically, the QoS information includes one or a combination of the following: data rate requirement, reliability requirement, priority, and packet delay budget. The reliability requirement can be reliability level information. Optionally, the RRC message includes synchronization timing information for each carrier frequency.

[0347] As shown in the analysis of Embodiment 1 above, the carrier frequency selection assistance information sent by the UE to the base station includes at least one of the following:

[0348] Logical channel identifier;

[0349] Logical channel group identifier;

[0350] Target identifier;

[0351] QoS information;

[0352] Number of carrier frequencies;

[0353] Multi-carrier frequency indication information; wherein the multi-carrier frequency indication information is used to indicate whether multi-carrier frequency transmission is used, or whether multi-carrier frequency data split transmission is used, or whether multi-carrier frequency data duplication transmission is used, or whether multi-carrier frequency data split and data duplication transmission is used.

[0354] V2X carrier frequency;

[0355] Synchronization timing information for each carrier; including one or a combination of the following: synchronization reference type (UE, GNSS, base station); coverage status of the synchronization source (indicating whether the synchronization source is within or outside coverage); absolute timing value of the synchronization source;

[0356] S1002: The eNB sends RRC Connection Reconfiguration to the UE, which includes resource allocation mode indication information (mode 3) and corresponding configuration information.

[0357] The base station can determine the UE's resource allocation mode based on the information in the RRC message received from the UE, generate corresponding resource allocation mode indication information, and send corresponding configuration information to the UE. Optionally, the base station can filter out timing-aligned carrier frequencies as a V2X carrier frequency set based on the synchronization timing information of each carrier frequency reported by the UE. Optionally, if the base station configures the UE to use the mode3 resource allocation method, the base station can filter out V2X carrier frequencies that can be used for UE transmission based on the CBR measurement results of each carrier frequency V2X resource pool in candidate carrier frequency set 1 or candidate carrier frequency set 2 reported by the UE (including the UE requesting resources or other UEs) to obtain candidate carrier frequency set 3. The V2X carrier frequency set sent by the base station to the UE can be sorted according to the CBR value of the resource pool on each carrier frequency, for example, the carrier frequency / resource pool with the lowest CBR value is ranked first.

[0358] Optionally, referring to Embodiment 1 above, the base station can also determine whether to use multi-carrier transmission, or determine the number of carriers, or determine the carrier data offloading ratio configuration information based on the QoS information reported by the UE. Of course, these processes can also be performed by the UE itself.

[0359] For example, in this step, the base station can determine whether to use multi-carrier data duplication and / or data split methods for data packets corresponding to the logical channel, logical channel group, or target identifier based on the QoS information reported by the UE. For example, the base station can calculate the reliability requirement based on the PPP value reported by the UE and the mapping relationship between PPP and reliability requirements, and then determine whether to use multi-carrier data duplication for transmission based on the reliability requirement. Alternatively, the base station can also determine whether to use multi-carrier data duplication for transmission based on the reliability requirement information reported by the UE. Alternatively, the base station can calculate the data rate requirement based on the data rate reported by the UE and the mapping relationship between PPP and data rate, and then determine whether to use multi-carrier data split for transmission based on the data rate requirement. Alternatively, the base station can also determine whether to use multi-carrier data split for transmission based on the data rate requirement information reported by the UE.

[0360] Optionally, if the base station determines that the UE needs to use multi-carrier data duplication and / or data split for transmission, it sends multi-carrier frequency indication information to the UE.

[0361] Therefore, in this embodiment, the carrier frequency selection control information sent by the base station to the UE via system messages or RRC proprietary signaling may include at least one of the following:

[0362] 2. Carrier frequency list:

[0363] 1) The carrier frequency used for transmission; or,

[0364] 2) The set of valid candidate carrier frequencies filtered based on the CBR results; or,

[0365] 3) The set of valid candidate carrier frequencies sorted according to the CBR results (e.g., the sorted set of candidate carrier frequencies 3);

[0366] 2. Number of carrier frequencies: Indicates the number of carrier frequencies required or the maximum number of carrier frequencies that can be used;

[0367] 3. Logical channel identifier;

[0368] 4. Logical channel group identifier;

[0369] 5. Target identifier or target index number;

[0370] 9. Multi-carrier frequency indication information, used to indicate whether multi-carrier frequency transmission is used;

[0371] 10. Data offloading ratio of the carrier frequency;

[0372] 11. Resource pool information;

[0373] 9. Information used to determine whether to use PC5 multi-carrier transmission:

[0374] 1) Priority threshold value. For example, if the PPPP value of a data packet is greater than the priority threshold value, the PC5CA function will not be used; if the PPPP value of a data packet is less than the priority threshold value, the PC5CA function can be used, including data split and data duplication.

[0375] 2) Buffer size threshold; 3) Data rate threshold; 4) Delay budget threshold; 5) Reliability threshold; 6) Reliability and delay budget thresholds; 7) Buffer size and delay budget thresholds;

[0376] 10. Information used to determine whether to use PC5 multi-carrier and / or the number of carriers:

[0377] 1) Buffer size range and corresponding number of carrier frequencies;

[0378] 2) Data rate range and corresponding number of carrier frequencies;

[0379] 3) Reliability range and corresponding number of carrier frequencies;

[0380] 4) Packet delay budget range and buffer size range and the corresponding number of carrier frequencies;

[0381] 5) Priority and corresponding number of carrier frequencies can be the number of carrier frequencies corresponding to the PPPP value / range;

[0382] 11. Information used to determine whether a carrier frequency is selectable for transmission:

[0383] 1) CBR threshold; 2) CBR threshold and corresponding priority; 3) CBR threshold and corresponding data rate; 4) CBR threshold and corresponding reliability; 5) CBR threshold and corresponding packet delay budget; 6) CBR threshold and corresponding frequency; 7) CBR threshold and corresponding resource pool.

[0384] S1003: The UE uses the carrier frequencies in the candidate carrier frequency set 3 obtained from the base station to perform PC5 data transmission. At this time, the base station performs the above-mentioned carrier frequency selection process; or, the UE performs carrier frequency selection in the candidate carrier frequency set 3 received from the base station. At this time, the UE performs carrier frequency selection.

[0385] If the resource configuration information received by the UE from the base station includes a logical channel identifier and a corresponding carrier frequency list, then the UE will perform subsequent carrier frequency selection (including the number of carrier frequencies and the specific carrier frequencies) and resource selection for the data in the logical channel in the corresponding carrier frequency list.

[0386] If the resource configuration information received by the UE from the base station includes a logical channel group identifier and a corresponding carrier frequency list, then the UE will perform subsequent carrier frequency selection and resource selection for the data in the logical channel group in the corresponding carrier frequency list.

[0387] If the resource configuration information received by the UE from the base station includes a target identifier and a corresponding carrier frequency list, the UE will perform subsequent carrier frequency selection and resource selection based on the target identifier in the corresponding carrier frequency list.

[0388] Optionally, for each logical channel, the UE performs CBR measurement on the resource pool of V2X carriers in the V2X carrier list (i.e., candidate carrier set 3) configured by the base station. Specifically, the resource pool information of the V2X carriers is obtained by the UE from the base station.

[0389] Optionally, the UE can select the timing-aligned carrier frequencies as the V2X carrier frequency set based on the synchronization timing information on each carrier frequency.

[0390] Optionally, if the UE obtains a CBR threshold value from the base station, the CBR threshold value is used to determine whether the carrier frequency where the V2X resource pool is located can be used for PC5 transmission. If the UE obtains a CBR threshold value and the corresponding carrier frequency from the base station, the UE uses the corresponding CBR threshold value on that carrier frequency; if the UE obtains a CBR threshold value and the corresponding resource pool from the base station, the UE uses the corresponding CBR threshold value on that resource pool; if the UE obtains a CBR threshold value and the corresponding priority from the base station, the UE determines its corresponding CBR threshold value based on the priority of the data to be transmitted or the priority of the data transmitted on that logical channel. If the UE obtains a CBR threshold value and the corresponding data rate requirement from the base station, the UE determines its corresponding CBR threshold value based on the data rate requirement of the data to be transmitted or the data rate requirement of the data transmitted on that logical channel. If the UE obtains a CBR threshold value and the corresponding reliability from the base station, the UE determines its corresponding CBR threshold value based on the reliability requirement of the data to be transmitted or the reliability requirement of the data transmitted on that logical channel. If the UE obtains the CBR threshold value and the corresponding packet delay budget requirement from the base station, the UE determines its corresponding CBR threshold value based on the packet delay budget requirement of the data to be transmitted or the packet delay budget requirement of the data transmitted on the logical channel.

[0391] The UE determines whether a carrier frequency containing a measured resource pool is usable for transmission based on the CBR measurement results of the V2X resource pools on each carrier frequency. For example, if the CBR measurement result of the resource pool is higher than the corresponding CBR threshold, the UE considers the carrier frequency unusable for transmission; if the CBR measurement result of the resource pool is lower than the corresponding CBR threshold, the UE considers the carrier frequency usable for transmission. The UE filters candidate carrier frequency set 4 based on the CBR measurement process of the resource pools in the V2X list configured for the base station, thus excluding carrier frequencies unusable for transmission. Optionally, the UE sorts the frequency points in candidate carrier frequency set 4 according to their CBR measurement values. For example, if the carrier frequencies are sorted from smallest to largest CBR measurement value, the frequency point with the smallest CBR measurement value is ranked first, and so on.

[0392] S1004: Determine whether to use multiple carrier frequencies for PC5 data transmission.

[0393] Optionally, if the base station generates the aforementioned multi-carrier transmission configuration information, the UE can determine whether to use multiple carriers for PC5 data transmission based on the configuration information received from the base station, including data splitting and / or data duplication.

[0394] 1) If the configuration information received by the UE from the base station includes a logical channel identifier and the corresponding multi-carrier frequency indication information, the UE determines whether the corresponding logical channel uses a multi-carrier frequency for PC5 data transmission based on the multi-carrier frequency indication information.

[0395] 2) If the configuration information received by the UE from the base station includes a logical channel group identifier and the corresponding multi-carrier frequency indication information, then determine whether the corresponding logical channel group uses multi-carrier frequency for PC5 data transmission based on the multi-carrier frequency indication information;

[0396] 3) If the configuration information received by the UE from the base station includes the target identifier and the corresponding multi-carrier frequency indication information, the UE determines whether the corresponding target identifier data should use the multi-carrier frequency for PC5 data transmission based on the multi-carrier frequency indication information.

[0397] The UE can also determine whether multi-carrier transmission is required based on the corresponding threshold information obtained from the base station, including but not limited to:

[0398] 4) If the UE receives priority threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the priority of the data to be transmitted and the priority threshold information. For example, if the priority value of the data to be transmitted (e.g., PPPP) is less than the configured priority threshold value, then multiple carriers can be used for PC5 data transmission.

[0399] 5) If the UE receives data rate threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the data rate requirement for the data to be transmitted and the data rate threshold information. For example, if the data rate requirement for the data to be transmitted is greater than the configured data rate threshold, then multiple carriers can be used for PC5 data transmission;

[0400] 6) If the UE receives buffer size threshold information from the base station, the UE determines whether multiple carrier frequencies can be used for PC5 data transmission based on the current logical channel's buffer size and the buffer size threshold information. For example, if the current logical channel's buffer size is greater than the configured buffer size threshold, multiple carrier frequencies can be used for PC5 data transmission.

[0401] 7) If the UE receives reliability threshold information from the base station, the UE determines whether to use multiple carriers for PC5 data transmission based on the reliability requirements of the data to be transmitted and the reliability threshold information. For example, if the reliability requirements of the data to be transmitted are higher than the configured reliability threshold, then multiple carriers can be used for PC5 data transmission.

[0402] 8) If the UE receives packet delay budget threshold information from the base station, the UE determines whether multiple carrier frequencies can be used for PC5 data transmission based on the packet delay budget of the data to be transmitted and the packet delay budget threshold information. For example, if the packet delay budget of the data to be transmitted is less than the configured packet delay budget threshold, multiple carrier frequencies can be used for PC5 data transmission.

[0403] S1005: Determine the number of carrier frequencies.

[0404] Optionally, the UE can determine the number of carrier frequencies to be used based on the service identifier information or QoS information of the data to be transmitted, and select a certain number of carrier frequencies from candidate carrier frequency set 3 or candidate carrier frequency set 4 received from the base station. If the base station performs the determination of the number of carrier frequencies, i.e., the generation of corresponding configuration information, the UE can obtain the carrier frequency configuration information from the base station, and then select a certain number of carrier frequencies from candidate carrier frequency set 3 or candidate carrier frequency set 4 received from the base station according to the received carrier frequency configuration information. Specifically, this can be divided into the following cases:

[0405] 1) If the resource configuration information received by the UE from the base station includes a logical channel identifier and the corresponding number of carrier frequencies, then the UE selects the corresponding number of carrier frequencies for transmission of data in the logical channel.

[0406] 2) If the resource configuration information received by the UE from the base station includes the logical channel group identifier and the corresponding number of carrier frequencies, then the UE selects the corresponding number of carrier frequencies for transmission of data in the logical channel group;

[0407] 3) If the resource configuration information received by the UE from the base station includes the target identifier and the corresponding number of carrier frequencies, then the UE selects the corresponding number of carrier frequencies for transmission of the data to be sent for the same target identifier;

[0408] 4) If the resource configuration information received by the UE from the base station includes a buffer size range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies that the logical channel needs to use or the maximum number of carrier frequencies that can be used based on the current buffer size range of the logical channel and the configured mapping relationship between the buffer size range and the number of carrier frequencies.

[0409] 5) If the resource configuration information received by the UE from the base station includes a data rate range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the range of the data rate requirement of the data to be transmitted and the mapping relationship between the configured data rate requirement range and the number of carrier frequencies.

[0410] 6) If the resource configuration information received by the UE from the base station includes the reliability range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the range of the reliability requirement of the data to be transmitted and the mapping relationship between the configured reliability requirement range and the number of carrier frequencies.

[0411] 7) If the resource configuration information received by the UE from the base station includes the packet delay budget range and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the range of the packet delay budget of the data to be transmitted and the mapping relationship between the configured packet delay budget range and the number of carrier frequencies.

[0412] 8) If the resource configuration information received by the UE from the base station includes the packet delay budget range and buffer size range and the corresponding number of carrier frequencies, then the UE determines the number of carrier frequencies that the logical channel needs to use or the maximum number of carrier frequencies that can be used based on the range of the packet delay budget of the data to be transmitted, the range of the current buffer size of the logical channel, and the mapping relationship between the configured packet delay budget range and buffer size range and the number of carrier frequencies.

[0413] For example, the base station can configure the number of carrier frequencies for the UE to be 200-400 bytes with a packet delay budget of 50ms, and 100ms with a packet delay budget of 100ms.

[0414] 9) If the resource configuration information received by the UE from the base station includes priority and the corresponding number of carrier frequencies, the UE determines the number of carrier frequencies required for the logical channel or the maximum number of carrier frequencies that can be used based on the priority of the data transmitted by the logical channel and the configured mapping relationship between priority and number of carrier frequencies.

[0415] S1006: Determine the amount of data to be transmitted on each carrier frequency.

[0416] If the UE determines that multiple carrier frequencies are needed for PC5 data transmission and has determined the carrier frequencies to be used for transmission, and the UE has not received the data offloading ratio of the carrier frequencies from the base station, then the UE will determine the amount of data to be transmitted on each of the selected carrier frequencies and send a BSR (Buffer Status Report) to the base station to request PC5 transmission resources on the corresponding carrier frequencies.

[0417] Alternatively, if the UE determines that multiple carrier frequencies are needed for PC5 data transmission and determines the carrier frequencies to be used for transmission, and the configuration information received by the UE from the base station includes carrier frequency data offloading ratio information, then the UE calculates the amount of data to be transmitted on each carrier frequency based on the carrier frequency data offloading ratio information, and sends a BSR to the base station to request PC5 transmission resources on the corresponding carrier frequencies.

[0418] Optionally, if the configuration information received by the UE from the base station includes a logical channel identifier, a carrier frequency list, and the corresponding carrier frequency data offloading ratio, then the UE uses the corresponding carrier frequency in the carrier frequency list to transmit data in the logical channel. Based on the configured data offloading ratio for each carrier frequency, the UE calculates the amount of data to be transmitted on each carrier frequency and sends a BSR to the base station to request PC5 transmission resources on the corresponding carrier frequency. For example, if the amount of data to be transmitted in logical channel 1 is 200 bytes, and it is determined that carrier frequency 1 and carrier frequency 2 will be used for transmission, and if the configuration information received by the UE from the base station indicates that the data offloading ratio for carrier frequency 1 is 80% and the data offloading ratio for carrier frequency 2 is 20%, then the UE calculates that the amount of data that can be transmitted using carrier frequency 1 is 160 bytes, and the amount of data that can be transmitted using carrier frequency 2 is 40 bytes.

[0419] If the configuration information received by the UE from the base station includes a logical channel group identifier, a carrier frequency list, and the corresponding carrier frequency data offloading ratio, then the UE will use the corresponding carrier frequency in the carrier frequency list to transmit the data in the logical channel group. The UE will also calculate the amount of data to be transmitted on each carrier frequency according to the configured data offloading ratio of each carrier frequency, and send a BSR to the base station to request PC5 transmission resources on the corresponding carrier frequency.

[0420] If the configuration information received by the UE from the base station includes a target identifier, a carrier frequency list, and the corresponding carrier frequency data offloading ratio, then the UE will use the corresponding carrier frequency in the carrier frequency list to transmit data for the same target identifier. The UE will also calculate the amount of data to be transmitted on each carrier frequency according to the configured data offloading ratio of each carrier frequency, and send a BSR to the base station to request PC5 transmission resources on the corresponding carrier frequency.

[0421] It should be understood that the above Figure 10 The steps shown can be freely combined, and the order of time can be adjusted.

[0422] The carrier frequency selection method provided in this embodiment can realize multi-carrier frequency communication between vehicle users within the base station coverage area (see [link]). Figure 11 and Figure 12 (as shown) and multi-carrier communication between vehicles in areas without coverage (see...) Figure 13 As shown in the diagram, when a vehicle user is within the base station coverage area, the carrier frequency used between vehicle users and the carrier frequency used for communication with the base station can be the same or different. Specifically, Figure 11 Vehicle UE1 and Vehicle UE2 communicate using carrier frequencies f2 and f3, while Vehicle UE2 communicates with the base station eNB using carrier frequency f1. Figure 12 Vehicle UE1 and Vehicle UE2 communicate with each other using carrier frequencies f1 and f2, while Vehicle UE2 communicates with the base station eNB using carrier frequency f1. Figure 13 Vehicle UE1 and Vehicle UE2, located in an area without coverage, communicate using carrier frequencies f2 and f3. It should be understood that the number of carrier frequencies used by Vehicle UE1 and Vehicle UE2 is not limited to the two shown in the diagram; the specific number may vary depending on the specific application scenario.

[0423] Example 6:

[0424] When V2X communication transmitting devices use multi-carrier frequency transmission, V2X communication receiving devices (which may also be vehicle terminals or user terminals) may not be able to receive V2X service data transmitted by the sender on multiple carrier frequencies simultaneously due to their limited receiving capabilities. In this case, it is necessary to solve the problem of how the receiving UE with limited receiving capabilities determines the carrier frequency to be received.

[0425] To address the above issues, this embodiment also provides a PC5 carrier frequency selection method to select the receiving carrier frequency, see [link to relevant documentation]. Figure 14 As shown, it includes:

[0426] S141: Obtain the priority corresponding to the service identifier or a list of service identifiers sorted by priority.

[0427] V2X receiver equipment can receive service identifiers and their corresponding priority values, or a list of service identifiers, from the base station. Optionally, the list of service identifiers is a list sorted according to the reception priority of the services; for example, the highest priority service is listed first, and so on. The base station can send the service identifiers and their corresponding priorities, or the list of service identifiers, to the UE via system messages or RRC dedicated signaling. Alternatively, the V2X receiver equipment can obtain the service identifiers and their corresponding priorities, or the list of service identifiers, based on pre-configuration or from the V2X control function or V2X application server.

[0428] S142: Based on the priority corresponding to the service identifier or a list of service identifiers sorted by priority, select the carrier frequencies corresponding to M higher priority services that can be received simultaneously within the range supported by the PC5 multi-carrier frequency receiving capability as receiving carrier frequencies, where M is an integer greater than or equal to 1.

[0429] The receiving UE can determine the V2X service identifiers it is interested in and obtain the set of V2X carrier frequencies it is interested in receiving based on the mapping relationship between service identifiers and V2X carrier frequencies. That is, the V2X receiving device obtains the carrier frequencies corresponding to each target service identifier based on the acquired target service identifiers and the preset service identifier-carrier frequency mapping relationship. When the V2X receiving device determines, based on its own PC5 multi-carrier reception capability information, that it cannot simultaneously receive V2X service data on all the carrier frequencies it is interested in receiving, it selects M services that can be received simultaneously, according to the priority of each service identifier from high to low, within the range supported by the PC5 multi-carrier reception capability information. Then, the V2X receiving device obtains the set of carrier frequencies to be received based on the V2X services that can be received simultaneously and the mapping relationship between V2X service identifiers and V2X carrier frequencies; or, within the range supported by the PC5 multi-carrier reception capability information, it sequentially selects the carrier frequencies corresponding to the M services that can be received simultaneously as the receiving carrier frequencies according to the order in the service identifier list. M is an integer greater than or equal to 1. The PC5 multi-carrier reception capability information includes at least one of the following: band combination information that supports simultaneous PC5 reception, band combination information that supports simultaneous PC5 and Uu reception, and Rx chain information.

[0430] This embodiment also provides a PC5 carrier frequency selection device, which can be installed in the V2X receiver equipment. See [link to documentation]. Figure 15 As shown, it includes:

[0431] The service acquisition module 151 is used to obtain the priority corresponding to the service identifier or a list of service identifiers sorted by priority.

[0432] The service acquisition module 151 can receive a service identifier and its corresponding priority value, or a list of service identifiers, from the base station. Optionally, the list of service identifiers is a list sorted by the base station according to the priority of the services; for example, the highest priority service is listed first, and so on. The base station can send the service identifier and its corresponding priority, or the list of service identifiers, to the UE via system messages or RRC dedicated signaling. Alternatively, the V2X receiving device can obtain the service identifier and its corresponding priority, or the list of service identifiers, based on pre-configuration or from the V2X control function or V2X application server. Then, the V2X receiving device can obtain the target service identifier from the obtained service identifiers (the target service identifier can be selected based on user selection or other factors).

[0433] The carrier frequency acquisition module 152 is used to select, within the range supported by the PC5 multi-carrier frequency reception capability, the carrier frequencies corresponding to M higher priority services that can be received simultaneously as receiving carrier frequencies, based on the priority corresponding to the service identifier or a list of service identifiers sorted by receiving priority. M is an integer greater than or equal to 1.

[0434] Specifically, the carrier frequency acquisition module 152 can be used to select M carrier frequencies that can be received simultaneously within the range supported by the PC5 multi-carrier frequency reception capability information when the V2X receiver device cannot simultaneously receive V2X service data on the carrier frequencies corresponding to each target service identifier, according to the priority of each target service identifier from high to low. M is an integer greater than or equal to 1. The PC5 multi-carrier frequency reception capability information includes at least one of the following: band combination information that supports simultaneous PC5 reception, band combination information that supports simultaneous PC5 and Uu reception, and Rx chain information.

[0435] It should be understood that the functions of the above modules can be implemented through the processor of the V2X receiver device.

[0436] This embodiment also provides a V2X receiver device, see [link]. Figure 16 As shown, the V2X receiver device includes a third processor 161, a third memory 162, and a third communication bus 163;

[0437] The third communication bus 163 is used to realize the connection and communication between the third processor 161 and the third memory 162;

[0438] The third processor 161 is used to execute one or more third programs stored in the third memory 162 to implement the steps of the PC5 carrier frequency selection method as described above;

[0439] or,

[0440] The third processor 161 is used to execute one or more fourth programs stored in the third memory 162 to implement the steps of the V2X service data receiving method as described above.

[0441] This embodiment also provides a computer storage medium that stores one or more programs, which are executed by one or more processors to implement the steps of the PC5 carrier frequency selection method as described above.

[0442] To facilitate understanding of the present invention, this embodiment uses a complete receiver UE's carrier frequency selection method as an example for illustration. See [link to documentation]. Figure 17 As shown, it includes:

[0443] S171: The receiving UE obtains the service identifier and the corresponding priority value or a list of service identifiers.

[0444] The UE can receive a service identifier and its corresponding priority value, or a list of service identifiers, from the base station. Optionally, the list of service identifiers is a list sorted by the base station according to the priority of the services; for example, the highest priority service is listed first, and so on. The base station can send the service identifier and its corresponding priority, or the list of service identifiers, to the UE via system messages or RRC dedicated signaling. Alternatively, the UE can obtain the service identifier and its corresponding priority, or the list of service identifiers, based on pre-configuration or from the V2X control function or V2X application server.

[0445] S172: The receiving UE determines the V2X service identifier it is interested in, and obtains the set of V2X carrier frequencies it is interested in receiving based on the mapping relationship between the V2X service identifier and the V2X carrier frequency.

[0446] S173: The receiving UE determines the set of carrier frequencies that it can simultaneously monitor based on its own PC5CA receiving capability, and selects the carrier frequencies.

[0447] In this step, if the UE cannot simultaneously listen to all V2X carrier frequencies it is interested in, it selects V2X services that it can simultaneously listen to, based on the service identifier and its corresponding priority, or a list of service identifiers, in descending order of service priority. Finally, the receiving UE obtains the set of carrier frequencies that it needs to simultaneously listen to based on the V2X services that can be simultaneously listened to and the mapping relationship between V2X service identifiers and V2X carrier frequencies. Specifically, the UE's PC5CA reception capability information includes one or a combination of the following: 1) band combination information for simultaneous PC5 reception; 2) band combination information for simultaneous PC5 / Uu reception; 3) number of Rx chains;

[0448] For example, V2X service 1 can be transmitted on frequencies 1 and 2, V2X service 2 can be transmitted on frequencies 3, 4, and 5, and V2X service 3 can be transmitted on frequencies 6 and 7. The priorities from high to low are: V2X service 1, V2X service 2, and V2X service 3. Suppose that the UE is interested in V2X services 1, 2, and 4, but according to the UE's PC5CA capability, it can only listen on two PC5 frequencies at the same time. Therefore, the UE will determine to listen only on f1 and f2 corresponding to V2X service 1, thereby ensuring that the high-priority service data of interest is received and improving the user experience satisfaction.

[0449] Obviously, those skilled in the art will understand that the modules or steps of the above-described embodiments of the present invention can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a computer storage medium (ROM / RAM, magnetic disk, optical disk) for execution by the computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Therefore, the present invention is not limited to any particular hardware and software combination.

[0450] The above description, in conjunction with specific implementation methods, provides a further detailed explanation of the embodiments of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A PC5 carrier frequency selection method, comprising: The initial candidate carrier frequency set of the V2X service data is obtained based on the service identifier and the service identifier-carrier frequency mapping relationship of the V2X service data. The transmission carrier frequency for the V2X service data is selected from the initial candidate carrier frequency set according to the carrier frequency selection information; wherein, the carrier frequency selection information includes the V2X transmitter PC5 multi-carrier transmission capability information, the V2X transmission carrier frequency set sent by the base station to the UE, and the V2X transmission carrier frequency set for no coverage. The process of selecting the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on carrier frequency selection information includes: When under base station coverage, the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE is obtained as the effective candidate carrier frequency set. When the base station is in a state of no coverage, the intersection of the initial candidate carrier frequency set and the carrier frequency set used for V2X transmission in the absence of coverage is obtained as the effective candidate carrier frequency set. The effective candidate carrier frequency set is obtained by filtering the channel busy ratio (CBR) measurement value of the V2X resource pool on each carrier frequency in the effective candidate carrier frequency set and the corresponding CBR measurement value threshold value. Based on the PC5 multi-carrier transmission capability information, select the maximum number of carrier frequencies within its own capability range from the filtered set of valid candidate carrier frequencies; Determine whether the V2X service data uses multi-carrier frequency transmission; When it is determined that multi-carrier transmission is required, a carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data; and the selected carrier frequency is determined based on the monitoring results to determine whether it meets the transmission requirements of the V2X service data. If not, another carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data, until the number of selected carrier frequencies meets the transmission requirements of the V2X service data.

2. The PC5 carrier frequency selection method as described in claim 1, characterized in that, The carrier frequency selection information includes at least one of synchronization reference timing information, quality of service (QoS) information, and carrier frequency selection control information. The carrier frequency selection control information includes at least one of the following: logical channel identifier, logical channel group identifier, target identifier, resource pool information, carrier frequency list, number of carrier frequencies, CBR threshold value, multi-carrier frequency indication information, information for determining whether to use multiple carrier frequencies, information for determining the number of carrier frequencies, and carrier frequency data offloading ratio. The information used to determine whether to use a multi-carrier frequency includes at least one of the following: Proximity Service Packet Priority (PPP) threshold; Data Rate threshold; Buffer Size threshold; Reliability threshold; Delay Budget threshold; The information used to determine the number of carrier frequencies includes at least one of the following: The range of buffer size and the corresponding number of carrier frequencies; the range of data rate and the corresponding number of carrier frequencies; the range of data reliability and the corresponding number of carrier frequencies; the range of packet delay budget and buffer size and the corresponding number of carrier frequencies; and the priority and the corresponding number of carrier frequencies.

3. The PC5 carrier frequency selection method as described in claim 2, characterized in that, The carrier frequency selection control information is obtained from the base station through system messages or RRC proprietary signaling, or through pre-configuration, or from the V2X control function, or from the V2X application server.

4. The PC5 carrier frequency selection method as described in claim 2, characterized in that, The step of selecting the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on carrier frequency selection information includes: When the carrier frequency selection control information includes the CBR threshold value, carrier frequencies in the initial candidate carrier frequency set whose measured channel busy ratio (CBR) value of the V2X resource pool on the carrier frequency is greater than the CBR threshold value of the V2X resource pool on that carrier frequency will be excluded. Alternatively, carriers in the initial candidate carrier set whose Channel Busy Ratio (CBR) measurement value of the V2X resource pool on the carrier is greater than the CBR threshold value of the V2X resource pool on that carrier are excluded, and the carriers in the initial candidate carrier set are arranged in ascending order according to the CBR measurement value of the V2X resource pool on each carrier.

5. The PC5 carrier frequency selection method as described in any one of claims 1-4, characterized in that, The determination of whether the V2X service data uses multi-carrier frequency transmission includes: Determine whether the V2X service data uses multi-carrier transmission based on the multi-carrier frequency indication information; Alternatively, determine whether the V2X service data uses multi-carrier frequency transmission based on the transmission parameters of the V2X service data and the corresponding transmission parameter threshold values; Alternatively, determine whether the V2X service data uses multi-carrier transmission based on the transmission parameters of the V2X service data and the corresponding number of carrier frequencies; The transmission parameters include at least one of the following: buffer size and quality of service (QoS) information. The QoS information includes at least one of the following: proximity packet priority (PPPP), data rate, data reliability, and packet delay budget.

6. The PC5 carrier frequency selection method as described in any one of claims 1-4, characterized in that, Selecting the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information includes: The number of carrier frequencies required for V2X service data transmission is determined based on the transmission parameters of the V2X service data and the corresponding number of carrier frequencies, or the number of carrier frequencies required for V2X service data transmission is determined based on the number of received carrier frequencies. Based on the determined number of carrier frequencies, a corresponding number of carrier frequencies are selected from the set of valid candidate carrier frequencies as the transmission carrier frequencies for the V2X service data; The transmission parameters include at least one of the following: buffer size and quality of service (QoS) information. The QoS information includes at least one of the following: proximity packet priority (PPPP), data rate, data reliability, and packet delay budget.

7. The PC5 carrier frequency selection method as described in claim 1, characterized in that, Before selecting the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information, the method further includes: An RRC message is sent to the base station. The RRC message includes carrier frequency selection assistance information, which includes V2X carrier frequency information.

8. The PC5 carrier frequency selection method as described in claim 7, characterized in that, The carrier frequency selection auxiliary information includes synchronization timing information, at least one of the following: PC5 multi-carrier transmission capability information of the V2X transmitting device, logical channel identifier, logical channel group identifier, target identifier, QoS information, number of carrier frequencies, and multi-carrier indication information; the synchronization timing information includes one or a combination of the following: synchronization reference type; coverage status of the synchronization source; absolute timing value of the synchronization source; the QoS information includes at least one of the following: proximity service packet priority (PPP), data rate, data reliability, and packet delay budget.

9. The PC5 carrier frequency selection method as described in claim 2, characterized in that, After selecting the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information, the method further includes: The amount of data to be transmitted on each selected carrier frequency is determined based on the carrier frequency data splitting ratio.

10. A PC5 carrier frequency selection method, comprising: Receive carrier frequency selection assistance information sent by V2X transmitting device, wherein the carrier frequency selection assistance information includes an initial candidate carrier frequency set of V2X service data obtained according to the service identifier of V2X service data and the service identifier-carrier frequency mapping relationship; The V2X transmitting device is sent carrier frequency selection control information so that the V2X transmitting device selects the transmission carrier frequency of the V2X service data from the initial candidate carrier frequency set according to the carrier frequency selection information; wherein, the carrier frequency selection information includes the V2X transmitting device PC5 multi-carrier frequency transmission capability information, the V2X transmission carrier frequency set sent by the base station to the UE, and the V2X transmission carrier frequency set for no coverage. The selection of the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information includes: When under base station coverage, the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE is obtained as the effective candidate carrier frequency set. When the base station is in a state of no coverage, the intersection of the initial candidate carrier frequency set and the carrier frequency set used for V2X transmission in the absence of coverage is obtained as the effective candidate carrier frequency set. The effective candidate carrier frequency set is obtained by filtering the channel busy ratio (CBR) measurement value of the V2X resource pool on each carrier frequency in the effective candidate carrier frequency set and the corresponding CBR measurement value threshold value. Based on the PC5 multi-carrier transmission capability information, select the maximum number of carrier frequencies within its own capability range from the filtered set of valid candidate carrier frequencies; Determine whether the V2X service data uses multi-carrier frequency transmission; When it is determined that multi-carrier transmission is required, a carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data; and the selected carrier frequency is determined based on the monitoring results to determine whether it meets the transmission requirements of the V2X service data. If not, another carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data, until the number of selected carrier frequencies meets the transmission requirements of the V2X service data.

11. The PC5 carrier frequency selection method as described in claim 10, characterized in that, The carrier frequency selection control information includes at least one of the following: logical channel identifier, logical channel group identifier, target identifier, resource pool information, carrier frequency list, number of carrier frequencies, CBR threshold value, multi-carrier frequency indication information, information for determining whether to use multiple carrier frequencies, information for determining the number of carrier frequencies, and carrier frequency data offloading ratio. The information used to determine whether to use a multi-carrier frequency includes at least one of the following: Proximity Packet Priority (PPP) threshold; Data Rate threshold; Buffer Size threshold; Reliability threshold; Delay Budget threshold; The information used to determine the number of carrier frequencies includes at least one of the following: The range of buffer size and the corresponding number of carrier frequencies; the range of data rate and the corresponding number of carrier frequencies; the range of data reliability and the corresponding number of carrier frequencies; the range of packet delay budget and buffer size and the corresponding number of carrier frequencies; and the priority and the corresponding number of carrier frequencies.

12. The PC5 carrier frequency selection method as described in claim 10 or 11, characterized in that, include: The carrier frequency selection auxiliary information includes at least one of the following: synchronization timing information and the PC5 multi-carrier frequency transmission capability information of the V2X transmitter device.

13. The PC5 carrier frequency selection method as described in claim 12, characterized in that, The carrier frequency selection auxiliary information also includes at least one of the following: logical channel identifier, logical channel group identifier, target identifier, QoS information, number of carrier frequencies, multi-carrier frequency indication information, and V2X carrier frequency; the synchronization timing information includes one or a combination of the following: synchronization reference type, coverage status of the synchronization source, and absolute timing value of the synchronization source.

14. A PC5 carrier frequency selection device, comprising: The initial selection module is used to obtain an initial candidate carrier frequency set for the V2X service data based on the service identifier of the V2X service data and the mapping relationship between the service identifier and the carrier frequency. The carrier frequency determination module is used to select the transmission carrier frequency of the V2X service data from the initial candidate carrier frequency set according to the carrier frequency selection information; wherein, the carrier frequency selection information includes V2X transmitter PC5 multi-carrier transmission capability information, V2X transmission carrier frequency set sent by the base station to the UE, and V2X transmission carrier frequency set for no coverage. The process of selecting the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on carrier frequency selection information includes: When under base station coverage, the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE is obtained as the effective candidate carrier frequency set. When the base station is in a state of no coverage, the intersection of the initial candidate carrier frequency set and the carrier frequency set used for V2X transmission in the absence of coverage is obtained as the effective candidate carrier frequency set. The effective candidate carrier frequency set is obtained by filtering the channel busy ratio (CBR) measurement value of the V2X resource pool on each carrier frequency in the effective candidate carrier frequency set and the corresponding CBR measurement value threshold value. Based on the PC5 multi-carrier transmission capability information, select the maximum number of carrier frequencies within its own capability range from the filtered set of valid candidate carrier frequencies; Determine whether the V2X service data uses multi-carrier frequency transmission; When it is determined that multi-carrier transmission is required, a carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data; and the selected carrier frequency is determined based on the monitoring results to determine whether it meets the transmission requirements of the V2X service data. If not, another carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data, until the number of selected carrier frequencies meets the transmission requirements of the V2X service data.

15. A PC5 carrier frequency selection device, comprising: The information receiving module is used to receive carrier frequency selection assistance information sent by the V2X transmitting device. The carrier frequency selection assistance information includes an initial candidate carrier frequency set of the V2X service data obtained according to the service identifier of the V2X service data and the service identifier-carrier frequency mapping relationship. A configuration processing module is used to send carrier frequency selection control information to the V2X transmitting end device, so that the V2X transmitting end device selects the transmission carrier frequency of the V2X service data from the initial candidate carrier frequency set according to the carrier frequency selection information; wherein, the carrier frequency selection information includes the V2X transmitting end device PC5 multi-carrier transmission capability information, the V2X transmission carrier frequency set sent by the base station to the UE, and the V2X transmission carrier frequency set for no coverage; The selection of the transmission carrier frequency for the V2X service data from the initial candidate carrier frequency set based on the carrier frequency selection information includes: When under base station coverage, the intersection of the initial candidate carrier frequency set and the V2X transmission carrier frequency set sent by the base station to the UE is obtained as the effective candidate carrier frequency set. When the base station is in a state of no coverage, the intersection of the initial candidate carrier frequency set and the carrier frequency set used for V2X transmission in the absence of coverage is obtained as the effective candidate carrier frequency set. The effective candidate carrier frequency set is obtained by filtering the channel busy ratio (CBR) measurement value of the V2X resource pool on each carrier frequency in the effective candidate carrier frequency set and the corresponding CBR measurement value threshold value. Based on the PC5 multi-carrier transmission capability information, select the maximum number of carrier frequencies within its own capability range from the filtered set of valid candidate carrier frequencies; Determine whether the V2X service data uses multi-carrier frequency transmission; When it is determined that multi-carrier transmission is required, a carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data; and the selected carrier frequency is determined based on the monitoring results to determine whether it meets the transmission requirements of the V2X service data. If not, another carrier frequency is selected from the filtered set of valid candidate carrier frequencies to transmit the V2X service data, until the number of selected carrier frequencies meets the transmission requirements of the V2X service data.

16. A V2X transmitter device, the V2X transmitter device comprising a first processor, a first memory, and a first communication bus; The first communication bus is used to realize the connection and communication between the first processor and the first memory; The first processor is configured to execute one or more first programs stored in the first memory to implement the steps of the PC5 carrier frequency selection method as described in any one of claims 1 to 9.

17. A base station, the base station comprising a second processor, a second memory, and a second communication bus; The second communication bus is used to realize the connection and communication between the second processor and the second memory; The second processor is used to execute one or more second programs stored in the second memory to implement the steps of the PC5 carrier frequency selection method as described in any one of claims 10 to 13.

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