Device-to-device communication method and system, apparatus, base station, and medium

Abstract

This disclosure provides a device-to-device (D2D) communication method, system, apparatus, base station, and medium. The method, applied to a central base station, includes: receiving a D2D communication request broadcast by each requesting terminal within a communication cycle; receiving an acknowledgment signal sent by an auxiliary terminal after confirming the storage of the file identified by the file identifier based on the received D2D communication request; constructing a bipartite graph based on the signal-to-noise ratio in the acknowledgment signal sent by the auxiliary terminal associated with each requesting terminal; and sending communication control signals to each requesting terminal and each auxiliary terminal according to the bipartite graph. This disclosure considers the influence of the channel environment and reduces the occurrence of communication failures.

Description

Technical Field

[0001] This disclosure relates to, but is not limited to, the field of communications, and particularly to a device-to-device communication method and system, apparatus, base station and medium. Background Technology

[0002] Advances in wireless communication technology have made high-speed and intelligent mobile living possible, but the exponential growth of mobile data traffic has also brought bottlenecks and challenges to traditional cellular networks. Against this backdrop, the concept of Device-to-Device (D2D) caching networks has been proposed to enhance distributed traffic offloading and improve network throughput. However, among related technologies, the wireless link discovery methods in D2D caching networks have weak anti-interference capabilities, and communication failures between devices occur frequently. Summary of the Invention

[0003] In view of the above, embodiments of this disclosure aim to provide a device-to-device communication method and system, apparatus, base station and medium.

[0004] In a first aspect, embodiments of this disclosure provide a device-to-device communication method applied to a central base station, the method comprising:

[0005] Within a communication cycle, a device-to-device (D2D) communication request broadcast by each requesting terminal is received; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal.

[0006] The receiving auxiliary terminal sends a confirmation signal after confirming that the file identified by the file identifier is stored based on the received D2D communication request; wherein, the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal;

[0007] A bipartite graph is constructed based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal.

[0008] According to the bipartite graph, communication control signals are sent to each of the requesting terminals and each of the auxiliary terminals; wherein, the communication control signals are used to indicate whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

[0009] In some embodiments, the method further includes:

[0010] Based on the bipartite graph, a multi-path augmentation algorithm is used to update the bipartite graph; wherein, the updated bipartite graph includes the largest number of communication matching terminals, and the communication matching terminals include the requesting terminal and the auxiliary terminals associated with the requesting terminal;

[0011] The step of sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0012] Based on the updated bipartite graph, the communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals. In some embodiments, the communication request further includes: a priority identifier of the requesting terminal;

[0013] The step of updating the bipartite graph using a multi-path augmentation algorithm based on the bipartite graph includes:

[0014] The bipartite graph is traversed in descending order of priority of the requesting terminals, and the bipartite graph is updated using the multi-path augmentation algorithm.

[0015] In some embodiments, sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0016] For each connection in the bipartite graph, determine whether there is co-frequency interference between the connection and other connections.

[0017] Count the number of connections that have co-channel interference with the aforementioned connection;

[0018] If the number of connections that have co-frequency interference with the connection is greater than a preset threshold, the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph is modified to "no connection".

[0019] Based on the bipartite graph after modifying the connection relationship, the communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals.

[0020] In some embodiments, constructing a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal includes:

[0021] If the signal-to-noise ratio is greater than a preset signal-to-noise ratio threshold, the connection relationship between the requesting terminal and the associated auxiliary terminal is set as a first connection identifier;

[0022] If the signal-to-noise ratio is less than or equal to the preset signal-to-noise ratio threshold, the connection relationship between the requesting terminal and the associated auxiliary terminal is set as a second connection identifier;

[0023] The bipartite graph is constructed based on the first connection identifier and the second connection identifier;

[0024] In the bipartite graph, the first connection identifier indicates that there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier;

[0025] The second connection identifier indicates that there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier.

[0026] In some embodiments, sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0027] If there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, the communication control signal carrying the first identifier of the requesting terminal, the second identifier of the auxiliary terminal, and the file identifier of the file requested by the requesting terminal is broadcast.

[0028] If there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, and the central base station has cached the file requested by the requesting terminal, it broadcasts the communication control signal carrying the first identifier of the requesting terminal and the file identifier of the file requested by the requesting terminal.

[0029] The method further includes:

[0030] The request file is sent to the requesting terminal during the communication cycle;

[0031] If, in the bipartite graph, there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier, and the central base station does not cache the file requested by the requesting terminal, the communication request carries the priority identifier of the requesting terminal, the priority identifier of the requesting terminal is modified, and the communication control signal carrying the priority identifier of the requesting terminal after modification is broadcast; wherein, the modified priority is higher than the original priority.

[0032] The method further includes:

[0033] In the next communication cycle, the requesting terminal with the modified priority identifier will be processed first.

[0034] Secondly, embodiments of this disclosure provide a device-to-device communication system, the system comprising: a requesting terminal, an auxiliary terminal, and a central base station; wherein,

[0035] The requesting terminal is configured to broadcast a device-to-device (D2D) communication request within a communication cycle; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal;

[0036] The auxiliary terminal is used to receive the D2D communication request; and is also used to send a confirmation signal to the central base station after confirming that the file identified by the file identifier is stored based on the D2D communication request; wherein the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal;

[0037] The central base station is configured to receive the D2D communication request sent by the requesting terminal and the confirmation signal sent by the auxiliary terminal; it is also configured to construct a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal including the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal; it is also configured to send communication control signals to each requesting terminal and each auxiliary terminal according to the bipartite graph; wherein the communication control signals are used to characterize whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period;

[0038] The requesting terminal and the auxiliary terminal are also used to communicate based on the communication control signal sent by the central base station.

[0039] Thirdly, embodiments of this disclosure provide a device-to-device communication apparatus applied to a central base station, the apparatus comprising:

[0040] The first receiving module is configured to receive a device-to-device (D2D) communication request sent by each requesting terminal within one communication cycle; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal.

[0041] The second receiving module is used to receive a confirmation signal sent by the auxiliary terminal after confirming that the file identified by the file identifier is stored based on the received D2D communication request; wherein the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal;

[0042] A construction module is used to construct a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal.

[0043] The sending module is configured to send communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph; wherein the communication control signals are used to indicate whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

[0044] Fourthly, embodiments of this disclosure provide a base station, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to perform the method described in the first aspect.

[0045] Fifthly, embodiments of this disclosure provide a storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0046] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0047] In the embodiments of this disclosure, within one communication cycle, the central base station receives a request signal sent by the requesting terminal and an acknowledgment signal sent by the auxiliary terminal. A bipartite graph is constructed based on the signal-to-noise ratio (SNR) of the acknowledgment signal, and a multipath augmentation algorithm is used to find the most frequent match in the bipartite graph. The connection relationship between the requesting terminal and the auxiliary terminal is then used to determine whether communication between them is permitted within the communication cycle. This disclosure constructs device-to-device connections based on the SNR of the communication channel, taking into account the influence of the channel environment and reducing the occurrence of communication failures.

[0048] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0050] Figure 1 This is a schematic diagram illustrating the implementation process of a device-to-device communication method provided in an embodiment of this disclosure;

[0051] Figure 2 This is an interactive schematic diagram of a device-to-device communication system provided in an embodiment of this disclosure;

[0052] Figure 3 This is a timing diagram of signal interaction in a device-to-device communication system provided in an embodiment of this disclosure;

[0053] Figure 4 This is a flowchart illustrating a multi-path augmentation algorithm provided in an embodiment of this disclosure;

[0054] Figure 5 This is a schematic flowchart of a co-channel interference control method provided in an embodiment of this disclosure;

[0055] Figure 6 This is a schematic diagram of a device-to-device communication apparatus applied to a central base station, provided in an embodiment of this disclosure;

[0056] Figure 7 This is a schematic diagram of the hardware entity of a base station provided in an embodiment of this disclosure. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this disclosure are further described in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limitations on this disclosure. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0058] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0059] If similar descriptions such as "first / second" appear in the application documents, the following explanation shall be added: The terms "first / second / third" used in this disclosure are merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for descriptive purposes only and is not intended to limit this disclosure.

[0061] Figure 1 This is a schematic diagram illustrating the implementation flow of a device-to-device communication method provided in an embodiment of this disclosure, applied to a central base station, such as... Figure 1 As shown, the method includes the following steps:

[0062] S101. Within one communication cycle, receive each device-to-device (D2D) communication request broadcast by a requesting terminal; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal.

[0063] S102. The auxiliary terminal receives a confirmation signal after confirming that the file identified by the file identifier is stored based on the received D2D communication request; wherein the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal.

[0064] S103. Based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal, construct a bipartite graph; wherein, the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal.

[0065] S104. According to the bipartite graph, a communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals; wherein, the communication control signal is used to characterize whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

[0066] In this embodiment, the communication time of the base station is measured in communication cycles, each cycle being further divided into inter-contact time and contact time. First, the central base station broadcasts a time signal across the entire frequency band, notifying all mobile terminals within its communication range (including the requesting terminal and auxiliary terminal in this embodiment) that the inter-contact time has begun. Within one communication cycle, after receiving the time signal broadcast by the central base station, the requesting terminal broadcasts a D2D communication request in a specific frequency band. This broadcast D2D communication request can be received by all devices within the communication range. The communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal.

[0067] In this embodiment of the disclosure, in step S101, the central base station can receive device-to-device (D2D) communication requests sent by each requesting terminal, and the auxiliary terminal can also receive D2D communication requests. After receiving the D2D communication request and confirming that the requested file is stored, the auxiliary terminal sends an acknowledgment signal to the central base station in a frequency band. That is, in step S102, the central base station can receive the acknowledgment signal sent by the auxiliary terminal. The acknowledgment signal carries a second identifier of the auxiliary terminal, a file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal.

[0068] It should be noted that the first identifier of the requesting terminal can be its device serial number, Universally Unique Identifier (UUID), or Media Access Control Address (MAC), or other information used to uniquely identify the requesting terminal; the file identifier of the file requested by the requesting terminal can be the requested file name, a Message-Digest Algorithm 5 (MD5) verification code, or other information used to uniquely identify the requested file; the second identifier of the auxiliary terminal can be its device serial number, UUID, or MAC, or other information used to uniquely identify the auxiliary terminal. The signal-to-noise ratio (SNR) refers to the ratio of signal to noise during communication between the requesting terminal and the auxiliary terminal. For example, a higher SNR value indicates a higher information transmission rate during communication; a lower SNR value indicates a lower information transmission rate during communication.

[0069] In this embodiment of the disclosure, requesting the terminal to broadcast D2D communication requests in different frequency bands means that the requesting terminal sends D2D communication requests to each auxiliary terminal and the central base station at different communication frequencies, ensuring that communication channels at different frequencies do not interfere with each other. It is understood that the auxiliary terminal sending acknowledgment signals to the central base station in different frequency bands is also to reduce interference between the communication channels of the auxiliary terminal and the central base station and other communication channels.

[0070] In step S103, the central base station can construct a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal.

[0071] In constructing the bipartite graph, the central base station jointly establishes the bipartite graph based on the first identifier of the requesting terminal, the second identifier of the auxiliary terminal containing the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio (SNR) of the requesting terminal and the auxiliary terminal. The bipartite graph includes the connection relationships between the requesting terminal and the auxiliary terminal. Theoretically, in constructing the bipartite graph, the requesting terminal and the associated auxiliary terminal can be connected (because the associated auxiliary terminal contains the file requested by the requesting terminal). However, in this embodiment of the disclosure, the bipartite graph is constructed in conjunction with the channel quality feedback from the SNR. If the channel quality of the communication channel between the requesting terminal and the associated auxiliary terminal is poor, the constructed bipartite graph will indicate that there is no connection between the requesting terminal and the associated auxiliary terminal.

[0072] In some embodiments, constructing a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal includes:

[0073] If the signal-to-noise ratio is greater than a preset signal-to-noise ratio threshold, the connection relationship between the requesting terminal and the associated auxiliary terminal is set as a first connection identifier;

[0074] If the signal-to-noise ratio is less than or equal to the preset signal-to-noise ratio threshold, the connection relationship between the requesting terminal and the associated auxiliary terminal is set as a second connection identifier;

[0075] The bipartite graph is constructed based on the first connection identifier and the second connection identifier;

[0076] In the bipartite graph, the first connection identifier indicates that there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier;

[0077] The second connection identifier indicates that there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier.

[0078] In embodiments of this disclosure, a D2D connected bipartite graph Boolean adjacency matrix can be initialized as shown in (1) below:

[0079]

[0080] The number of requesting terminals is N. R The number of auxiliary terminals is N H , Characterizes the Boolean value for D2D connections.

[0081] In this embodiment of the disclosure, the reference numeral N is assumed to be... R The requesting terminal and the label N H The signal-to-noise ratio between auxiliary terminals is The preset signal-to-noise ratio threshold is SNR.THR For example, In formula (1), The characterization label is N R The requesting terminal and the label N H The auxiliary terminal has a D2D connection; hour, The characterization label is N R The requesting terminal and the label N H The auxiliary terminal does not have a D2D connection.

[0082] For example, the number of requesting terminals is 4, and the number of auxiliary terminals is 4, namely requesting terminals 1, 2, 3, and 4, and auxiliary terminals A, B, C, and D. Based on the signal-to-noise ratio of the communication channel between the requesting terminals and the associated auxiliary terminals, a D2D connected bipartite graph Boolean adjacency matrix is ​​constructed as shown in the following (2):

[0083]

[0084] In this embodiment of the disclosure, the impact of environmental interference on the communication channel is considered. If the signal-to-noise ratio is smaller, it means that the noise mixed in the signal is larger. A communication channel with a small signal-to-noise ratio has relatively poor communication quality. Marking the requesting terminal and the auxiliary terminal whose signal-to-noise ratio does not meet the threshold as having no D2D connection can reduce the occurrence of transmission failure during communication.

[0085] In step S104, the central base station broadcasts communication control signals based on the connection relationship between the requesting terminal and the auxiliary terminal in the constructed bipartite graph.

[0086] It should be noted that the communication control signal can be either a signal allowing the requesting terminal and the auxiliary terminal to communicate within the contact time of the current communication cycle, or a signal denying communication between the requesting terminal and the auxiliary terminal within the contact time of the current communication cycle. For example, if the requesting terminal and the associated auxiliary terminal are connected in the constructed bipartite graph, the central base station broadcasts a signal allowing communication between the requesting terminal and the associated auxiliary terminal within the communication cycle. Correspondingly, after receiving the communication control signal, the requesting terminal and the associated auxiliary terminal communicate within the contact time of the communication cycle, and the auxiliary terminal transmits the file requested by the requesting terminal to the requesting terminal. If the requesting terminal and the auxiliary terminal are not connected in the constructed bipartite graph, the central base station broadcasts a signal denying communication between the requesting terminal and the auxiliary terminal within the communication cycle. Correspondingly, the requesting terminal and the auxiliary terminal cannot perform D2D communication, meaning the auxiliary terminal will not transmit the file requested by the requesting terminal to the requesting terminal.

[0087] In related technologies, it is assumed that the popularity (probability of being requested) of each requested file follows a Zipf distribution. A caching strategy is formulated based on popularity, considering caching multiple files on auxiliary terminals to maximize the cache hit rate (the probability that a terminal caches a requested file). Files with higher popularity are cached with a higher probability, files with slightly lower popularity are cached with a moderate probability, and files that are requested less frequently are cached with a lower probability. Based on this caching strategy, the requesting terminal and auxiliary terminal are further matched. The assumption that the popularity of each requested file follows a Zipf distribution is only applicable to network simulation. D2D connection discovery and interference control methods based on this premise have poor robustness and cannot be applied to complex interference environments.

[0088] In contrast, the device-to-device communication method provided in this disclosure involves the central base station receiving a request signal from a requesting terminal and an acknowledgment signal from an auxiliary terminal within a communication cycle. A bipartite graph is constructed based on the signal-to-noise ratio (SNR) of the acknowledgment signal, and a multipath augmentation algorithm is used to find the most frequent match in the bipartite graph. The connection relationship between the requesting terminal and the auxiliary terminal is then used to determine whether communication between them is permitted within the communication cycle. This disclosure constructs the device-to-device connection relationship based on the SNR of the communication channel, taking into account the influence of the channel environment and reducing the occurrence of communication failures.

[0089] In some embodiments, the method further includes:

[0090] Based on the bipartite graph, a multi-path augmentation algorithm is used to update the bipartite graph; wherein, the updated bipartite graph includes the largest number of communication matching terminals, and the communication matching terminals include the requesting terminal and the auxiliary terminals associated with the requesting terminal;

[0091] The step of sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0092] Based on the updated bipartite graph, the communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals.

[0093] In the embodiments of this disclosure, after constructing the bipartite graph, the central base station can update the bipartite graph using a multipath augmentation algorithm. It should be noted that the multipath augmentation algorithm includes: the Hungarian algorithm, the Dinic algorithm, the Shortest Path Faster Algorithm (SPFA), etc., and the embodiments of this disclosure do not limit the multipath augmentation algorithm used.

[0094] The multi-path augmentation algorithm can find the maximum number of matches in a bipartite graph, which corresponds to the maximum number of requesting terminals and associated auxiliary terminals. For example, in a bipartite graph, auxiliary terminals A and B both cache files requested by requesting terminal 1, and auxiliary terminal A caches files requested by requesting terminal 2. Taking the Hungarian algorithm as an example, in the bipartite graph constructed based on the above caching relationship, first find the augmenting path for requesting terminal 1, and the matching result found is: requesting terminal 1 and auxiliary terminal A. Then find the augmenting path for requesting terminal 2, and the matching results found are: requesting terminal 1 and auxiliary terminal B, and requesting terminal 2 and auxiliary terminal A. It can be understood that in the second augmentation path finding of this embodiment, a new communication link is added to the matching result compared to the first matching result. After the second matching, the number of communication matching terminals is greater, so that one requesting terminal can correspond to one auxiliary terminal. The same auxiliary terminal does not need to satisfy the file requests of multiple requesting terminals simultaneously within a communication cycle, thus improving the success rate of D2D communication between requesting terminals and auxiliary terminals.

[0095] In embodiments of this disclosure, the central base station sends the communication control signal to each of the requesting terminals and each of the auxiliary terminals according to the updated bipartite graph.

[0096] This disclosure employs a multi-path augmentation algorithm to find the maximum match, which can establish as many communication connections as possible, thereby improving the efficiency of D2D communication.

[0097] In some embodiments, the communication request further includes: a priority identifier of the requesting terminal;

[0098] The step of updating the bipartite graph using a multi-path augmentation algorithm based on the bipartite graph includes:

[0099] The bipartite graph is traversed in descending order of priority of the requesting terminals, and the bipartite graph is updated using the multi-path augmentation algorithm.

[0100] In embodiments of this disclosure, the communication request further includes a priority identifier, which may be pre-assigned to each requesting terminal by the central base station. For example, the central base station may negotiate the priority with the requesting terminal during the time period between the broadcast time signal and the receipt of the requesting terminal's D2D communication request.

[0101] In this embodiment of the disclosure, the central base station traverses the requesting terminals in descending order of priority to find augmenting paths until all requesting terminals have been traversed.

[0102] For example, the priority identifiers of request terminals 1, 2, 3, and 4 are 1, 2, 3, and 4, respectively. Among them, the request terminal corresponding to priority identifier 1 has the highest priority. Based on the aforementioned Boolean adjacency matrix (2), starting from request terminal 1 with priority identifier 1, there is an augmenting path, and the found match is request terminal 1 - auxiliary terminal A; looking for the augmenting path of request terminal 2 with priority identifier 2, there is an augmenting path, and the found match is request terminal 2 - auxiliary terminal B and request terminal 1 - auxiliary terminal A; looking for the augmenting path of request terminal 3 with priority identifier 3, there is an augmenting path, and the found match is request terminal 3 - auxiliary terminal A, request terminal 1 - auxiliary terminal B, and request terminal 2 - auxiliary terminal C; looking for the augmenting path of request terminal 4 with priority identifier 4, there is no augmenting path, and all request terminals have been traversed. The updated bipartite graph Boolean adjacency matrix is ​​as follows (3):

[0103]

[0104] The largest match found is between requesting terminal 3 and auxiliary terminal A, requesting terminal 1 and auxiliary terminal B, and requesting terminal 2 and auxiliary terminal C. At this point, the number of matching connections is the largest, and the number of matching terminals is the highest.

[0105] In this embodiment of the disclosure, the maximum matching method of the multi-path augmentation algorithm is used to find augmenting paths. By marking the priority order of the requesting terminal traversing the augmenting paths, as many communication connections as possible can be established based on the priority, which is beneficial to improving the fairness of D2D communication.

[0106] In some embodiments, sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0107] For each connection in the bipartite graph, determine whether there is co-frequency interference between the connection and other connections.

[0108] Count the number of connections that have co-channel interference with the aforementioned connection;

[0109] If the number of connections that have co-frequency interference with the connection is greater than a preset threshold, the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph is modified to "no connection".

[0110] Based on the bipartite graph after modifying the connection relationship, the communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals.

[0111] In the embodiments of this disclosure, for each connection in the bipartite graph, it is determined whether there is co-channel interference between that connection and other connections. If the communication frequency of that connection is the same as that of other connections, co-channel interference is considered to exist. Connections with co-channel interference cannot be activated simultaneously, and interfering connections need to be excluded.

[0112] In this embodiment of the disclosure, a symmetric Boolean matrix of co-frequency interference for D2D connections can be initialized, as shown in (4) below:

[0113]

[0114] The number of D2D connections is N. C h ij The Boolean value characterizing co-channel interference in a D2D connection. For example, h ij =1 indicates that there is co-channel interference between the two D2D connections; h ij =0 indicates that there is no co-frequency interference between the two D2D connections.

[0115] This embodiment can update the bipartite graph by combining co-channel interference with the aforementioned adjacency matrix (2) or (3). Taking the adjacency matrix (3) as an example, there are 3 connections: requesting terminal 1 - auxiliary terminal B (connection 1), requesting terminal 2 - auxiliary terminal C (connection 2), and requesting terminal 3 - auxiliary terminal A (connection 3). The corresponding co-channel interference Boolean value symmetric matrix of the D2D connection is as follows (5):

[0116]

[0117] Among them, connection 1 is subject to co-frequency interference with connection 2 and connection 3.

[0118] In this embodiment, the central base station counts the number of connections that have co-channel interference with each connection. It finds that the number of connections with connection 1 that have co-channel interference is 2, the number of connections with connection 2 that have co-channel interference is 1, and the number of connections with connection 3 that have co-channel interference is 1. Based on the count of co-channel interference, it determines whether the number of connections with co-channel interference with the connection is greater than a preset threshold. If it is greater than the preset threshold, the connection relationship between the requesting terminal and the auxiliary terminal corresponding to connection 1 in the bipartite graph is changed to "no connection".

[0119] If the preset quantity threshold is 1, the number of connections with co-channel interference to connection 1 is greater than the preset quantity threshold, and the number of connections with co-channel interference to connections 2 and 3 is equal to the preset quantity threshold, then only the connection relationship between the requesting terminal and the auxiliary terminal corresponding to connection 1 in the bipartite graph is modified to be non-existent. The modified bipartite graph Boolean adjacency matrix is ​​shown below (6):

[0120]

[0121] In the modified bipartite graph, there are two remaining connections: requesting terminal 2—auxiliary terminal C (connection 2) and requesting terminal 3—auxiliary terminal A (connection 3). Based on the modified bipartite graph, the central base station counts the number of connections that have co-channel interference with each connection for connections 2 and 3. It finds that the number of connections that have co-channel interference with connection 2 is 0, and the number of connections that have co-channel interference with connection 3 is 0. At this point, there are no interfering connections in the bipartite graph.

[0122] In this embodiment of the disclosure, in the D2D link maximum matching scheme established by the multipath augmentation algorithm, if a D2D connection has co-channel interference with multiple other connections, and the number of interfering connections is greater than a preset threshold, it indicates that the other connections will have a significant impact on the connection, and the communication success rate of the connection will be low. In response, the central base station modifies the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph to a non-existent connection, which can reduce invalid communication, improve communication quality, and allow the communication resources saved by reducing the connection to be allocated to other terminals.

[0123] In some embodiments, updating the bipartite graph using a multi-path augmentation algorithm based on the bipartite graph includes:

[0124] Based on the bipartite graph, a multi-path augmentation algorithm is used to traverse the requesting terminal to determine whether an augmentation path has been found in the current traversal.

[0125] If the augmenting path is found in the current traversal, the bipartite graph is updated according to the augmenting path.

[0126] In the embodiments disclosed herein, it should be noted that the requesting terminals can be traversed according to the first identifier of the requesting terminal, or according to the file identifier of the file requested by the requesting terminal.

[0127] In the embodiments of this disclosure, the central base station traverses the requesting terminal using a multi-path augmentation algorithm based on the bipartite graph to find augmenting paths. When starting the search for an augmenting path within a communication cycle, a preset number of matches can be set. The system then determines whether an augmenting path has been found in the current traversal. For example, if the number of found matches is greater than the preset number of matches, it indicates that the requesting terminal has an augmenting path, and the preset number of matches is updated to the number of found matches. If the number of found matches is less than or equal to the preset number of matches, it indicates that the requesting terminal does not have an augmenting path. If an augmenting path is found in the current traversal, the bipartite graph is updated based on the augmenting path found in the current traversal.

[0128] In this embodiment of the disclosure, the multipath augmentation algorithm can increase the number of matching connections and matching terminals in the matching process by continuously finding augmenting paths, and the multipath augmentation algorithm can find as many connections as possible.

[0129] In some embodiments, sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0130] If there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, a communication control signal carrying the first identifier of the requesting terminal, the second identifier of the auxiliary terminal, and the file identifier of the file requested by the requesting terminal is broadcast.

[0131] In this embodiment of the disclosure, if a connection exists between the requesting terminal and the associated auxiliary terminal in the bipartite graph, the central base station sends a communication control signal indicating that the requesting terminal is permitted to communicate with the associated auxiliary terminal. The communication control signal received by the requesting terminal and the associated auxiliary terminal carries a first identifier of the requesting terminal, a second identifier of the auxiliary terminal, and a file identifier of the file requested by the requesting terminal. According to the communication control signal, the auxiliary terminal can transmit the file corresponding to the file identifier to the requesting terminal corresponding to the first identifier.

[0132] In this embodiment, the central base station sends a communication control signal to allow the requesting terminal and its associated auxiliary terminal to communicate within a communication period. D2D communication enables direct data transmission between devices without base station forwarding, significantly reducing the base station's load. Furthermore, the central base station can agree on communication frequencies with each requesting terminal and each auxiliary terminal during the broadcast time signal, ensuring that communication signals from different communication channels do not interfere with each other when the requesting terminal communicates with its associated auxiliary terminal. This unified scheduling and allocation by the central base station maximizes the efficiency of D2D spectrum reuse.

[0133] In some embodiments, sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes:

[0134] If there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, and the central base station has cached the file requested by the requesting terminal, it broadcasts the communication control signal carrying the first identifier of the requesting terminal and the file identifier of the file requested by the requesting terminal.

[0135] The method further includes:

[0136] The request file is sent to the requesting terminal during the communication cycle.

[0137] In this embodiment of the disclosure, if there is no connection between the requesting terminal and the associated auxiliary terminal in the bipartite graph, the central base station sends a communication control signal indicating that communication between the requesting terminal and the auxiliary terminal is refused. Since the communication control signal received by the disconnected requesting terminal and the auxiliary terminal does not carry the second identifier of the auxiliary terminal, the disconnected requesting terminal and the auxiliary terminal cannot communicate according to this communication control signal.

[0138] Furthermore, in this embodiment of the present disclosure, if the central base station caches the file requested by the requesting terminal, the communication control signal sent by the central base station carries the first identifier of the requesting terminal and the file identifier of the file requested by the requesting terminal. During the communication period, the central base station and the requesting terminal can communicate, and the central base station sends the file requested by the requesting terminal to the requesting terminal.

[0139] In this embodiment of the disclosure, the central base station sends a communication control signal to reject the requesting terminal from communicating with the associated auxiliary terminal. The central base station and the requesting terminal communicate during the communication period. In the case that D2D communication is not possible, the central base station uses its own cache to transmit the request file to the corresponding requesting terminal, which can satisfy the communication request of the requesting terminal as much as possible.

[0140] It should be noted that, considering the limited capacity of content to be transmitted in a single transmission, this disclosure allows for segmented transmission of the content to be transmitted, thereby improving the success rate. For example, if the data size of the requested file exceeds the capacity, the central base station can send the requested file in segments to the corresponding requesting terminal multiple times.

[0141] In some embodiments, if the communication request also carries a priority identifier of the requesting terminal, the step of sending communication control signals to each requesting terminal and each auxiliary terminal according to the bipartite graph includes:

[0142] If, in the bipartite graph, there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier, and the central base station does not cache the file requested by the requesting terminal, the priority identifier of the requesting terminal is modified, and the communication control signal carrying the priority identifier of the requesting terminal after modification is broadcast; wherein, the modified priority is higher than the original priority.

[0143] In this embodiment of the disclosure, if there is no connection between the requesting terminal and the associated auxiliary terminal in the bipartite graph, the central base station sends a communication control signal indicating that the requesting terminal is refused communication with the auxiliary terminal. Furthermore, if the central base station does not cache the file requested by the requesting terminal, it modifies the priority identifier of the requesting terminal to a higher priority. In the next communication cycle, the priority identifier of the requesting terminal is the modified priority identifier.

[0144] In this embodiment, if the requesting terminal does not find a matching auxiliary terminal and the base station does not cache the file requested by the requesting terminal, the priority identifier of the requesting terminal is modified to a higher priority according to priority order. Relative to the next communication cycle, the priority of a requesting terminal that has not found an associated auxiliary terminal in the current communication cycle should be higher than that of a requesting terminal with a communication request in the next communication cycle. It is understood that modifying the priority identifier of the requesting terminal allows the next communication cycle to prioritize finding a matching auxiliary terminal, thus compensating for the waiting time in the current communication cycle.

[0145] In some embodiments, the method further includes:

[0146] In the next communication cycle, the requesting terminal with the modified priority identifier will be processed first.

[0147] In this embodiment of the disclosure, for a requesting terminal that has not been matched with a corresponding auxiliary terminal and the base station has not cached the file requested by the requesting terminal, the priority identifier of the requesting terminal is modified to a higher priority according to the priority order, and a matching auxiliary terminal is searched first in the next communication cycle to compensate for the waiting time of the current communication cycle.

[0148] Figure 2 This is an interactive schematic diagram of a device-to-device communication system provided in an embodiment of this disclosure, such as... Figure 2 As shown, it includes the following steps:

[0149] S201. Within one communication cycle, the requesting terminal broadcasts a device-to-device (D2D) communication request; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal.

[0150] S202. After confirming that the file identified by the file identifier is stored based on the received D2D communication request, the auxiliary terminal sends a confirmation signal; wherein, the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal;

[0151] S203. The central base station constructs a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein, the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal.

[0152] S204. The central base station sends communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph; wherein, the communication control signals are used to indicate whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period;

[0153] S205. The requesting terminal and the auxiliary terminal communicate based on the communication control signal sent by the central base station.

[0154] Figure 3 This is a timing diagram of signal interaction in a device-to-device communication system provided in this disclosure embodiment. The following is in conjunction with... Figure 2 and Figure 3 The device-to-device communication system disclosed herein is further described in detail below:

[0155] In this embodiment of the disclosure, Figure 3 The instruction in ① indicates that the central base station broadcasts a time signal across the entire frequency band to notify all mobile terminals within its communication range that inter-contact communication has begun. Subsequently, execution... Figure 2 In step S201, within one communication cycle, the terminal is requested to broadcast a device-to-device (D2D) communication request, which corresponds to... Figure 3 ②. After receiving the D2D communication request and confirming that the requested file is stored, the auxiliary terminal executes... Figure 2 In step S202, the auxiliary terminal sends an acknowledgment signal to the central base station, which corresponds to... Figure 3 In point ③, the confirmation signal carries the signal-to-noise ratio (SNR) of the communication channel between the auxiliary terminal and the requesting terminal. For example, a higher SNR value results in a higher information transmission rate when the requesting terminal and the auxiliary terminal communicate; a lower SNR value results in a lower information transmission rate when the requesting terminal and the auxiliary terminal communicate.

[0156] After receiving the D2D request signal and confirmation signal, the central base station executes... Figure 2 Steps S203 and S204 in the text correspond to Figure 3 ④ in the middle.

[0157] exist Figure 2 In step S203, the central base station jointly constructs a bipartite graph based on the first identifier of the requesting terminal, the second identifier of the auxiliary terminal containing the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the requesting terminal and the auxiliary terminal. The bipartite graph includes the connection relationships between the requesting terminal and the auxiliary terminal. In the constructed bipartite graph, if the channel quality of the communication channel between the requesting terminal and the associated auxiliary terminal is poor, the requesting terminal and the associated auxiliary terminal are marked as having no connection.

[0158] After constructing the bipartite graph, the central base station executes... Figure 2In step S204, the central base station broadcasts a communication control signal; wherein the communication control signal is used to characterize whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

[0159] Figure 3 The instruction in section ⑤ indicates that the execution will take place after the start of the contact communication time within the communication cycle. Figure 2 In step S205, the requesting terminal and the auxiliary terminal communicate based on the communication control signal sent by the central base station.

[0160] It should be noted that the communication control signal can be either a signal that allows the requesting terminal and the auxiliary terminal to communicate during the communication cycle, or a signal that denies the requesting terminal and the auxiliary terminal from communicating during the communication cycle. For example, when the requesting terminal and the auxiliary terminal receive a signal that allows them to communicate during the communication cycle, it indicates that the auxiliary terminal has cached the file requested by the requesting terminal, and a connection exists between the requesting terminal and the auxiliary terminal. During the communication cycle, the auxiliary terminal sends the requested file to the requesting terminal. Conversely, when the requesting terminal and the auxiliary terminal receive a signal that denies them from communicating during the communication cycle, for example, if the central base station has cached the file requested by the requesting terminal, the central base station sends the requested file to the requesting terminal during the communication cycle. Alternatively, if the central base station does not have cached the file requested by the requesting terminal, in the next communication cycle, the central base station will decide whether to allow the requesting terminal to communicate with the auxiliary terminal or whether to send the requested file to the requesting terminal itself, based on the received D2D request signal from the requesting terminal, the confirmation signal from the auxiliary terminal, and whether it has cached the file requested by the requesting terminal.

[0161] In this embodiment of the disclosure, the device-to-device connection relationship is constructed based on the signal-to-noise ratio of the communication channel, taking into account the influence of the channel environment, which can reduce the occurrence of communication failures; in addition, the multipath augmentation algorithm is used to find the maximum match, which can establish as many communication connections as possible, thereby improving the efficiency of D2D communication.

[0162] Figure 4 This is a flowchart illustrating a multi-path augmentation algorithm provided in an embodiment of this disclosure, as shown below. Figure 4 As shown, it includes the following steps:

[0163] S401. Initialize the priority label of the requesting terminal;

[0164] S402. Starting from the request terminal with the highest priority, traverse sequentially to find an augmenting path;

[0165] S403. Determine if the requesting terminal has an augmentation path; if yes, proceed to step S404; if no, proceed to step S405.

[0166] S404. Based on the augmenting path, update the bipartite graph and continue to step S405;

[0167] S405. Determine whether all request terminals have been traversed; if yes, proceed to step S406; if no, proceed to step S402.

[0168] S406. Modify the priority identifier of the unmatched request terminal. The modified priority is higher than the original priority. Output the updated bipartite graph.

[0169] In embodiments of this disclosure, in step S401, the D2D communication request sent by the requesting terminal received by the central base station also includes a priority identifier, which may be pre-assigned by the central base station to each requesting terminal. For example, the central base station may negotiate the priority with the requesting terminal during the time period from after the broadcast time signal to before receiving the D2D communication request from the requesting terminal. After receiving the D2D communication request sent by the requesting terminal and confirming that the requesting terminal's request file is stored, the auxiliary terminal sends an acknowledgment signal to the central base station. The central base station constructs a bipartite graph based on the signal-to-noise ratio in the acknowledgment signal. Based on the constructed bipartite graph, step S402 is executed, whereby the central base station uses a multipath augmentation algorithm to find augmenting paths. During the search for augmenting paths, step S403 is executed. The central base station determines whether the requesting terminal corresponding to the current priority has an augmenting path. For example, if an augmenting path is found, it means that a new match has been added between the current requesting terminal and the associated auxiliary terminal. Then, step S404 is executed to update the bipartite graph based on the newly added match found by the augmenting path, and step S405 is executed to determine whether all requesting terminals have been traversed. If no augmenting path is found, step S405 is executed again to determine whether all requesting terminals have been traversed. Based on the result of step S405, if all requesting terminals have been traversed, step S406 is executed to modify the priority identifier of the unmatched requesting terminals. The modified priority is higher than the original priority, and the updated bipartite graph is output. If all requesting terminals have not been traversed, step S402 is executed to continue searching for augmenting paths until all requesting terminals have been traversed.

[0170] In this embodiment of the disclosure, the maximum matching method of the multi-path augmentation algorithm is used to find augmenting paths. By marking the priority order of the requesting terminal traversing the augmenting paths, as many communication connections as possible can be established based on the priority, which is beneficial to improving the fairness of D2D communication.

[0171] Figure 5 This is a flowchart illustrating a co-channel interference control method provided in an embodiment of this disclosure, as shown below. Figure 5 As shown, it includes the following steps:

[0172] S501, Input a bipartite graph with D2D connection;

[0173] S502. Calculate the total number of interferences for each D2D connection;

[0174] S503. Determine whether the maximum total number of interferences is greater than the preset threshold; if yes, proceed to step S504; if no, proceed to step S505.

[0175] S504. Modify the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the total number of interferences in the bipartite graph to be non-existent, update the bipartite graph, and continue to execute step S502.

[0176] S505, Output the updated bipartite graph.

[0177] In the embodiments of this disclosure, during the process of eliminating co-channel interference, the central base station first executes step S501, inputting a bipartite graph of D2D connections; based on the connection relationship between the requesting terminal and the auxiliary terminal in the bipartite graph, it executes step S502, whereby the central base station, for each connection in the bipartite graph, determines whether co-channel interference exists between the connection and other connections, and counts the number of connections with co-channel interference, i.e., the total number of interferences for each D2D connection. If the communication frequency of the connection and other connections is the same, co-channel interference is considered to exist. Connections with co-channel interference cannot be activated simultaneously and the interfering connections need to be eliminated. The number of connections other than those with the same frequency as the connection is the total number of interferences for that connection.

[0178] For each connection, identify the number of connections with co-channel interference. Select the connection with the largest number of co-channel interferences and proceed to step S503. Determine if the maximum number of co-channel interferences is greater than a preset threshold. For example, if the maximum number of co-channel interferences is less than or equal to the preset threshold, proceed to step S505 and output the updated bipartite graph. If the maximum number of co-channel interferences is greater than the preset threshold, proceed to step S504. Modify the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph to "no connection" and update the bipartite graph. Based on the updated bipartite graph, proceed to steps S502 and S503 again until the maximum number of co-channel interferences is less than or equal to the preset threshold. Then, proceed to step S505 and output the updated bipartite graph.

[0179] In this embodiment of the disclosure, in the D2D link maximum matching scheme established by the multipath augmentation algorithm, if a D2D connection has co-channel interference with other connections, and the number of interfering connections is greater than a preset threshold, it indicates that the other connections will have a significant impact on the connection, and the communication success rate of the connection will be low. In response, the central base station modifies the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph to a non-existent connection, which can reduce invalid communication, improve communication quality, and allow the communication resources saved by reducing the connection to be allocated to other terminals.

[0180] Figure 6 This is a schematic diagram of a device-to-device communication apparatus applied to a central base station, as provided in an embodiment of this disclosure. Figure 6 As shown, the device-to-device communication device 600 includes:

[0181] The first receiving module 601 is configured to receive a device-to-device (D2D) communication request broadcast by each requesting terminal within a communication cycle; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal.

[0182] The second receiving module 602 is used to receive a confirmation signal sent by the auxiliary terminal after confirming that the file identified by the file identifier is stored based on the received D2D communication request; wherein the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal;

[0183] The construction module 603 is used to construct a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal.

[0184] The sending module 604 is used to send communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph; wherein the communication control signals are used to indicate whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

[0185] In some embodiments, the apparatus further includes:

[0186] The update module 605 updates the bipartite graph using a multi-path augmentation algorithm based on the bipartite graph; wherein the updated bipartite graph contains the largest number of communication matching terminals, and the communication matching terminals include the requesting terminal and the auxiliary terminals associated with the requesting terminal;

[0187] The sending module 604 is further configured to send the communication control signal to each of the requesting terminals and each of the auxiliary terminals according to the updated bipartite graph.

[0188] In some embodiments, the communication request further includes: a priority identifier of the requesting terminal; the update module 605 is further configured to traverse the bipartite graph in descending order of the priority of the requesting terminal and update the bipartite graph using the multipath augmentation algorithm.

[0189] In some embodiments, the sending module 604 is further configured to, for each connection in the bipartite graph, determine whether there is co-channel interference between the connection and other connections; count the number of connections that have co-channel interference with the connection; if the number of connections that have co-channel interference with the connection is greater than a preset threshold, modify the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph to be non-existent; and send the communication control signal to each requesting terminal and each auxiliary terminal according to the bipartite graph after modifying the connection relationship.

[0190] In some embodiments, the construction module 603 is further configured to: if the signal-to-noise ratio is greater than a preset signal-to-noise ratio threshold, set the connection relationship between the requesting terminal and the associated auxiliary terminal as a first connection identifier; if the signal-to-noise ratio is less than or equal to the preset signal-to-noise ratio threshold, set the connection relationship between the requesting terminal and the associated auxiliary terminal as a second connection identifier; and construct the bipartite graph based on the first connection identifier and the second connection identifier; wherein, in the bipartite graph, the first connection identifier indicates that there is a connection between the requesting terminal identified by the first identifier and the associated auxiliary terminal identified by the second identifier; and the second connection identifier indicates that there is no connection between the requesting terminal identified by the first identifier and the associated auxiliary terminal identified by the second identifier.

[0191] In some embodiments, the sending module 604 is further configured to broadcast a communication control signal carrying the first identifier of the requesting terminal, the second identifier of the auxiliary terminal, and the file identifier of the file requested by the requesting terminal if there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph.

[0192] In some embodiments, the sending module 604 is further configured to broadcast a communication control signal carrying the first identifier of the requesting terminal and the file identifier of the file requested by the requesting terminal if there is no connection between the requesting terminal identified by the first identifier and the associated auxiliary terminal identified by the second identifier in the bipartite graph, and the central base station has cached the file requested by the requesting terminal.

[0193] The device further includes:

[0194] The transmission module 606 sends the request file to the requesting terminal during the communication cycle.

[0195] In some embodiments, the sending module 604 is further configured to: if there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, and the central base station does not cache the file requested by the requesting terminal, and the communication request carries the priority identifier of the requesting terminal, modify the priority identifier of the requesting terminal, and broadcast the communication control signal carrying the priority identifier of the requesting terminal after modification; wherein the modified priority is higher than the original priority;

[0196] The device further includes:

[0197] The processing module 607 prioritizes the requesting terminal after modifying the priority identifier in the next communication cycle.

[0198] Figure 7 This is a schematic diagram of a hardware entity of a base station in an embodiment of this disclosure, such as... Figure 7 As shown, the hardware entity of the base station 700 includes a processor 701, a communication interface 702, and a memory 703, wherein the processor 701 typically controls the overall operation of the base station 700. The communication interface 702 enables the base station to communicate with other terminals or servers via a network.

[0199] The memory 703 is configured to store instructions and applications executable by the processor 701, and can also cache data to be processed or already processed (e.g., image data, audio data, voice communication data, and video communication data) from the processor 701 and various modules in the base station 700. It can be implemented using flash memory or random access memory (RAM). Data can be transferred between the processor 701, the communication interface 702, and the memory 703 via bus 704. The processor 701 is used to execute some or all of the steps in the above method.

[0200] Correspondingly, embodiments of this disclosure provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements some or all of the steps in the above method.

[0201] It should be noted that the descriptions of the storage medium and base station embodiments above are similar to the descriptions of the method embodiments above, and have similar beneficial effects. For technical details not disclosed in the storage medium and base station embodiments of this disclosure, please refer to the descriptions of the method embodiments of this disclosure for understanding.

[0202] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this disclosure. Therefore, "in one embodiment" or "one embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this disclosure, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this disclosure. The sequence numbers of the above-described embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0203] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0204] In the several embodiments provided in this disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0205] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0206] In addition, each functional unit in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0207] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0208] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, or the part that contributes to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, magnetic disks, or optical disks.

[0209] The above description is merely an embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A device-to-device communication method, characterized in that, Applied to a central base station, the method includes: Within a communication cycle, a device-to-device (D2D) communication request broadcast by each requesting terminal is received; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal. The receiving auxiliary terminal sends a confirmation signal after confirming that the file identified by the file identifier is stored based on the received D2D communication request; wherein, the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal; A bipartite graph is constructed based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal. According to the bipartite graph, communication control signals are sent to each of the requesting terminals and each of the auxiliary terminals; wherein, the communication control signals are used to indicate whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

2. The method according to claim 1, characterized in that, The method further includes: Based on the bipartite graph, a multi-path augmentation algorithm is used to update the bipartite graph; wherein, the updated bipartite graph includes the largest number of communication matching terminals, and the communication matching terminals include the requesting terminal and the auxiliary terminals associated with the requesting terminal; The step of sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes: Based on the updated bipartite graph, the communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals.

3. The method according to claim 2, characterized in that, The communication request also includes: the priority identifier of the requesting terminal; The step of updating the bipartite graph using a multi-path augmentation algorithm based on the bipartite graph includes: The bipartite graph is traversed in descending order of priority of the requesting terminals, and the bipartite graph is updated using the multi-path augmentation algorithm.

4. The method according to any one of claims 1 to 3, characterized in that, The step of sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes: For each connection in the bipartite graph, determine whether there is co-frequency interference between the connection and other connections. Count the number of connections that have co-channel interference with the aforementioned connection; If the number of connections that have co-frequency interference with the connection is greater than a preset threshold, the connection relationship between the requesting terminal and the auxiliary terminal corresponding to the connection in the bipartite graph is modified to "no connection". Based on the bipartite graph after modifying the connection relationship, the communication control signal is sent to each of the requesting terminals and each of the auxiliary terminals.

5. The method according to claim 1, characterized in that, The construction of a bipartite graph based on the signal-to-noise ratio of the confirmation signal sent by the auxiliary terminal associated with each requesting terminal includes: If the signal-to-noise ratio is greater than a preset signal-to-noise ratio threshold, the connection relationship between the requesting terminal and the associated auxiliary terminal is set as a first connection identifier; If the signal-to-noise ratio is less than or equal to the preset signal-to-noise ratio threshold, the connection relationship between the requesting terminal and the associated auxiliary terminal is set as a second connection identifier; The bipartite graph is constructed based on the first connection identifier and the second connection identifier; In the bipartite graph, the first connection identifier indicates that there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier; The second connection identifier indicates that there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier.

6. The method according to claim 1, characterized in that, The step of sending communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph includes: If there is a connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, the communication control signal carrying the first identifier of the requesting terminal, the second identifier of the auxiliary terminal, and the file identifier of the file requested by the requesting terminal is broadcast. If there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier in the bipartite graph, and the central base station has cached the file requested by the requesting terminal, it broadcasts the communication control signal carrying the first identifier of the requesting terminal and the file identifier of the file requested by the requesting terminal. The method further includes: The request file is sent to the requesting terminal during the communication cycle; If, in the bipartite graph, there is no connection between the requesting terminal identified by the first identifier and the auxiliary terminal identified by the associated second identifier, and the central base station does not cache the file requested by the requesting terminal, the communication request carries the priority identifier of the requesting terminal, the priority identifier of the requesting terminal is modified, and the communication control signal carrying the priority identifier of the requesting terminal after modification is broadcast; wherein, the modified priority is higher than the original priority. The method further includes: In the next communication cycle, the requesting terminal with the modified priority identifier will be processed first.

7. A device-to-device communication system, characterized in that, The system includes: a request terminal, an auxiliary terminal, and a central base station; wherein... The requesting terminal is configured to broadcast a device-to-device (D2D) communication request within a communication cycle; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal; The auxiliary terminal is used to receive the D2D communication request; and is also used to send a confirmation signal to the central base station after confirming that the file identified by the file identifier is stored based on the D2D communication request; wherein the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal; The central base station is configured to receive the D2D communication request sent by the requesting terminal and the confirmation signal sent by the auxiliary terminal; it is also configured to construct a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal including the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal; it is also configured to send communication control signals to each requesting terminal and each auxiliary terminal according to the bipartite graph; wherein the communication control signals are used to characterize whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period; The requesting terminal and the auxiliary terminal are also used to communicate based on the communication control signal sent by the central base station.

8. A device-to-device communication apparatus, characterized in that, The device, applied to a central base station, includes: The first receiving module is configured to receive a device-to-device (D2D) communication request sent by each requesting terminal within one communication cycle; wherein the communication request carries a first identifier of the requesting terminal and a file identifier of the file requested by the requesting terminal. The second receiving module is used to receive a confirmation signal sent by the auxiliary terminal after confirming that the file identified by the file identifier is stored based on the received D2D communication request; wherein the confirmation signal carries the second identifier of the auxiliary terminal, the file identifier of the file requested by the requesting terminal, and the signal-to-noise ratio of the communication channel between the auxiliary terminal and the requesting terminal; A construction module is used to construct a bipartite graph based on the signal-to-noise ratio in the confirmation signal sent by the auxiliary terminal associated with each requesting terminal; wherein the auxiliary terminal associated with the requesting terminal is a terminal that includes the file requested by the requesting terminal, and the bipartite graph includes the connection relationship between the requesting terminal identified by the first identifier carried in the D2D communication request and the auxiliary terminal identified by the second identifier carried in the confirmation signal. The sending module is configured to send communication control signals to each of the requesting terminals and each of the auxiliary terminals according to the bipartite graph; wherein the communication control signals are used to indicate whether the requesting terminal is allowed to communicate with the associated auxiliary terminal during the communication period.

9. A base station, characterized in that, include: processor; Memory used to store processor-executable instructions; The processor is configured to perform the method as described in any one of claims 1 to 6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1 to 6.

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