A multi-to-one relay selection method for distributed networks

Abstract

The application discloses a kind of multi-to-one relay selection methods for distributed network, it is related to distributed network communication technical field, research global transmission rate fairness optimization problem in limited wireless network of relay node, by considering the performance of whole network source node in resource allocation process, the overall performance between relays is considered simultaneously, so that relay network reaches the optimization of average performance, realizes the stable result of whole network.The method is characterized by: source node and relay node have their own decision-making ability, source node selects efficient transmission relay link to meet its transmission rate requirement, relay node knows the transmission rate information of source node connected with it, and decides whether to accept the request of source node according to its selection criteria.By optimizing the relay selection strategy of source node to maximize the transmission rate of all source nodes, the optimal relay allocation result of whole network is realized.

Description

Technical Field

[0001] This invention relates to the field of distributed network communication technology, and more specifically to a many-to-one relay selection method for distributed networks. Background Technology

[0002] With the rapid development of wireless communication technology, distributed networks, with their advantages of self-organization, high scalability, and resilience, have been widely used in fields such as the Internet of Things (IoT), vehicle-to-everything (V2X) communication, and emergency communications. However, the dynamic nature of nodes, resource constraints, and time-varying channel characteristics lead to challenges such as reduced transmission reliability, limited coverage, and uneven energy consumption. Relay communication technology, through cooperative forwarding between nodes, can effectively extend network coverage, enhance link reliability, and improve system capacity, becoming a key supporting technology for improving the performance of distributed networks. In distributed networks, relay nodes, by forwarding signals from source nodes, can effectively overcome channel defects such as path loss and multipath fading, improving overall network capacity and user service quality. Furthermore, traffic scheduling by relay nodes can balance network load, avoid congestion in hotspot areas, and improve spectrum utilization.

[0003] While relay communication technology offers significant advantages in distributed network communication, its performance largely depends on the rational allocation of relay resources. In dynamic and complex distributed networks, optimizing the fairness of relay allocation is particularly crucial. On one hand, differences in node energy, time-varying channel characteristics, and dynamic topology changes can cause some nodes to remain under high load for extended periods, exacerbating uneven network energy consumption. On the other hand, when multiple users compete for the same relay node, relying solely on instantaneous channel quality or local information can easily lead to resource allocation imbalances, affecting the long-term stability of the network. With numerous nodes distributed throughout the network, a rational allocation of relay resources can significantly increase the network's transmission capacity and efficiency.

[0004] Therefore, from the perspective of optimizing the overall network transmission rate, there is currently no solution to the problem of relay node allocation in wireless networks in order to achieve global optimization of relay distribution. Summary of the Invention

[0005] In view of this, the present invention provides a many-to-one relay selection method for distributed networks, which can study the fairness optimization problem of global transmission rate in wireless networks with limited relay nodes. By considering the performance of all source nodes in the network and the overall performance between relays during the resource allocation process, the relay network can achieve average performance optimization and realize the stable result of the entire network.

[0006] To achieve the above objectives, the technical solution of the present invention includes the following steps:

[0007] Step 1: Construct a relay network system model with multiple source nodes to one destination node, including a set of source nodes. Relay node set , destination node set .

[0008] Step 2: All source nodes in the network construct a relay node preference list; each source node ranks the relay nodes according to their transmission rate preference; the source node makes a connection request according to the relay node ranking in the preference list; the relay node accepts all connection requests and provides feedback to the source node on the actual transmission rate it can obtain, and ranks the source nodes according to the transmission rate to form a source node list.

[0009] Step 3: All source nodes compare the current transmission rate with the transmission rate achievable in direct transmission mode; if the transmission rate achievable by the current connection is lower than that in direct transmission mode, the source node abandons the current relay connection and attempts to select the next relay node from the preference list.

[0010] Each source node that has not established a connection with a relay node updates its preference list until only the direct transmission mode can be selected.

[0011] Step 4, relay node Randomly select a source node to establish a connection with itself. Source node Find a better relay node If the source node With relay node Connection can be improved and The total transmission rate of the two relay nodes, and the relay node Accept source node Application; simultaneously, relay node The source node will be removed from the list of connected source nodes. .

[0012] Step 5: If the relay selection strategy of all source nodes cannot be changed during the selection process, it means that the entire network has reached a stable solution, and the output is the final distributed many-to-one selection result; otherwise, repeat steps 3-5.

[0013] Furthermore, in step 1, a relay network system model of multiple source nodes to one destination node is constructed, specifically as follows:

[0014] In a relay network, the source node requests a forwarding request from the relay node to achieve cooperative spatial diversity. The relay node periodically broadcasts its own location information and forwards the received signals to the destination node. The source node and the relay node select appropriate items from each other's sets according to their respective selection criteria.

[0015] There are N source nodes, M relay nodes, and K destination nodes; the set of source nodes is: The relay node set is as follows: and the destination node A source node is allowed to connect to at most one relay node, while a relay node can connect to multiple source nodes simultaneously.

[0016] For a source-relay node pair, the selection criterion for each source node is to find the relay node that can provide the maximum transmission rate, thereby meeting their respective transmission rate requirements; the relayed node is defined. The source node of the service The transmission rate is:

[0017]

[0018] relay node The transmission rate is:

[0019]

[0020] in, For indicator functions, when the source node Successfully connected to the relay node hour, Otherwise, it equals 0.

[0021] Furthermore, in step 2, when the source node is included... Multiple source nodes selected the same relay node Source node It will share relay link resources with other source nodes.

[0022] Source node According to transmission rate Construct a preference list; where For the source node The actual transmission rate that can be obtained.

[0023] The preference list is as follows: This preference relation represents the source node. The best choice is ,if Rejected The request, Will target the next relay node Submit an application, and so on. This indicates that no relay node has been selected.

[0024] Relay nodes accept all applications from source nodes on a first-come, first-served basis, allocate time resources evenly, and reject other source nodes. Rejected source nodes receive feedback and search for and apply for the next relay connection. Similarly, relay nodes provide feedback to the receiving source nodes on the actual transmission rate they can obtain and arrange the source nodes according to the transmission rate to form a source node list.

[0025] Furthermore, For the source node The actual transmission rate that can be obtained:

[0026]

[0027] in, Indicates access to relay node The number of source nodes; Indicates by emission, Forwarding and The received transmission rate; This represents the signal-to-noise ratio from transmission at the source node to reception at the relay node; This represents the signal-to-noise ratio from the source node to the destination node; This represents the signal-to-noise ratio (SNR) from transmission at the relay node to reception at the destination node. Indicates the channel bandwidth; where express In relay Transmitted to the destination node with the assistance of ,and Indicates the source node With the target node Direct communication, i.e., direct transmission mode.

[0028] Further, step 3 specifically involves:

[0029] The source node updates the preference list, specifically by updating the preference list for each source node. When selecting a relay node The transmission rate at that time is less than the transmission rate in direct transmission mode, that is... hour, Abandon the current relay node Change the preference list; until a relay node is found. This enables relay nodes to... The transmission rate at that time is greater than or equal to the transmission rate in direct transmission mode, that is... , .

[0030] Each source node that has not established a connection with a relay node will update its preference list until only direct transmission mode is available. Source nodes that do not meet the requirements for changing relay nodes will maintain their connection to the original relay node.

[0031] Further, in step 4, for connections to the relay node... All source nodes, Randomly select one of the source nodes It is recommended that they find a better relay option; when the source node To the new relay node When submitting the application, it will carry the previously connected relay node. The transmission rate allows relay nodes to compare transmission rates and make a selection; if the source node Connecting relay nodes At that time, the source node The transmission efficiency is greater than that of the source node. Connecting relay nodes Transmission efficiency at that time, i.e. Then the source node To relay node Submit a connection request; if this option allows the relay node to... With relay node Total transmission rate If an additional relay node is added, the relay node will be added. Accept source node The application must be approved by the source node; otherwise, the application will be rejected. The selected relay node will not be abandoned. ;Source node In determining to connect to another relay node After that, the previous relay node Remove it from the list.

[0032] Beneficial effects:

[0033] (1) This invention provides a many-to-one relay selection method for distributed networks. The method is characterized by the following features: both source nodes and relay nodes have their own decision-making capabilities. The source node selects a relay link with high-efficiency transmission to meet its own transmission rate requirements. The relay node knows the transmission rate information of the source nodes connected to it and decides whether to accept the source node's request based on its selection criteria. By optimizing the relay selection strategy of the source nodes, the transmission rate of all source nodes is maximized, thereby achieving the optimal relay allocation result for the entire network. It can be seen that this invention studies the fairness optimization problem of global transmission rate in a wireless network with limited relay nodes. By considering the performance of all source nodes in the network during resource allocation, and simultaneously considering the overall performance between relays, the relay network achieves average performance optimization, resulting in a stable overall network outcome.

[0034] (2) This invention improves the fairness of the global transmission rate of the wireless network with limited relay nodes. By effectively sharing the relay, the source nodes promote the balance of their transmission rates and achieve a balanced allocation of network resources.

[0035] (3) In the process of resource allocation, the present invention takes into account the performance of all source nodes in the network, and improves the performance of all source nodes as much as possible. In the process of relay allocation, it suggests that source nodes with poor performance find better relay nodes to connect to, thus solving the problem of fairness in relay allocation in the relay network and realizing global optimization of relay allocation. Attached Figure Description

[0036] Figure 1 It is a relay network system model with multiple source nodes and one destination node;

[0037] Figure 2 This is a flowchart of a many-to-one relay selection algorithm for distributed networks. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] This invention proposes a many-to-one relay selection method for distributed networks, the process of which is as follows: Figure 2 As shown, this paper studies the fairness optimization problem of global transmission rate in a wireless network with limited relay nodes. By considering the performance of all source nodes and the overall performance among relays during resource allocation, the algorithm optimizes the average performance of the relay network and achieves a stable result for the entire network. The algorithm is characterized by the fact that both source nodes and relay nodes have their own decision-making capabilities. Source nodes select efficient relay links to meet their own transmission rate requirements, while relay nodes know the transmission rate information of the source nodes connected to them and decide whether to accept the source node's request based on selection criteria. By optimizing the relay selection strategy of source nodes, the transmission rate of all source nodes is maximized, thereby achieving the optimal relay allocation result for the entire network.

[0040] The technical solution of the present invention includes the following steps:

[0041] Step 1: Construct a relay network system model with multiple source nodes and one destination node, including a set of source nodes. Relay node set , destination node set The source node requests forwarding from the relay node to achieve cooperative spatial diversity. The relay node periodically broadcasts its location information and forwards received signals to the destination node. The source node and the relay node select appropriate items from each other's sets according to their respective selection criteria.

[0042] Step 2: All source nodes in the network construct a relay node preference list. Each source node ranks the relay nodes according to their transmission rate preference. The source node submits a connection request based on the relay nodes in the preference list. The relay nodes accept all connection requests and provide feedback to the source nodes on the actual transmission rate they can obtain. They then rank the source nodes according to the transmission rate to form a source node list.

[0043] Step 3: Source nodes update their preference lists. All source nodes compare their current transmission rate with the transmission rate achievable in direct transmission mode. If the transmission rate achievable with the current connection is lower than that in direct transmission mode... At that time, the source node The current relay connection will be abandoned, and the next relay node in the preference list will be selected. Each source node that has not established a connection with a relay node will update the preference list until only direct transmission mode can be selected.

[0044] Step 4, relay node Randomly select a source node to establish a connection with itself. Let it find a better relay node. If the source node With relay node Connection can be improved and The total transmission rate of the two relay nodes, and the relay node Will accept the source node The application was submitted. Meanwhile, the relay node... The source node will be removed from the list of connected source nodes. .

[0045] Step 5: If the relay selection strategy of all source nodes cannot be changed during the selection process, it means that the entire network has reached a stable solution, and the output is the final distributed many-to-one selection result; otherwise, repeat steps 3-5.

[0046] In this embodiment of the invention, for step 1, a relay network system model with multiple source nodes and one destination node is constructed, such as... Figure 1 As shown. In a relay network, there are N One source node, M relay nodes and K There are destination nodes. The source node set is: The relay node set is as follows: and the destination node A source node is allowed to connect to at most one relay node, while a relay node can connect to multiple source nodes simultaneously.

[0047] For a source-relay node pair, the selection criterion for each source node is to find the relay node that can provide the maximum transmission rate, thereby fulfilling their respective transmission rate requirements. Define the relayed node. The source node of the service The transmission rate is:

[0048]

[0049] A relay node knows the transmission rate of the source nodes it connects to and will prefer to serve transmission links with higher transmission rates to maximize its own transmission rate. The transmission rate can be written as:

[0050]

[0051] in, For indicator functions, when the source node Successfully connected to the relay node hour, Otherwise, it equals 0.

[0052] In this embodiment of the invention, for step 2, when the source node is included... Multiple source nodes selected the same relay node Source node It will share relay link resources with other source nodes. Source node The actual transmission rate that can be obtained for:

[0053]

[0054] in, Indicates access to relay node The number of source nodes; Indicates by emission, Forwarding and The received transmission rate; This represents the signal-to-noise ratio from transmission at the source node to reception at the relay node; This represents the signal-to-noise ratio from the source node to the destination node; This represents the signal-to-noise ratio (SNR) from transmission at the relay node to reception at the destination node. Indicates the channel bandwidth; where express In relay Transmitted to the destination node with the assistance of ,and Indicates the source node With the target node Direct communication, i.e., direct transmission mode.

[0055] Source node According to transmission rate Construct a preference list. Example Preference list: This preference relationship represents the source node. The best choice is ,if Rejected The request, Will be for the next relay node Submit an application, and so on.

[0056] Relay nodes accept all applications from source nodes on a first-come, first-served basis, allocate time resources evenly, and reject other source nodes. Rejected source nodes receive feedback and then search for and apply for the next relay connection. Similarly, relay nodes provide feedback to receiving source nodes on the actual transmission rate they can obtain and rank the source nodes according to transmission rate, forming a source node list.

[0057] In this embodiment of the invention, for step 3, the source node updates the preference list. For each source node... When selecting a relay node The transmission rate at that time is less than the transmission rate in direct transmission mode, that is... hour, Abandon the current relay node Change the preference list; until a relay node is found. This enables relay nodes to... The transmission rate at that time is greater than or equal to the transmission rate in direct transmission mode, that is... , .

[0058] Each source node that has not established a connection with a relay node will update its preference list until only direct transmission mode is available. Source nodes that do not meet the requirements for changing relay nodes will maintain their connection to the original relay node. This indicates that no relay node has been selected.

[0059] In this embodiment of the invention, for step 4, for connecting to the relay node... All source nodes, Randomly select one of the source nodes It is recommended that they find a better relay option. When the source node... To the new relay node When submitting the application, it will carry the previously connected relay node. The transmission rate allows relay nodes to compare transmission rates and make a selection. If the source node... Connecting relay nodes At that time, the source node The transmission efficiency is greater than that of the source node. Connecting relay nodes Transmission efficiency at that time, i.e. Then the source node To relay node Submit a connection request. If this option allows the relay node... With relay node Total transmission rate If an additional relay node is added, the relay node will be added. Accept source node The application must be approved by the source node; otherwise, the application will be rejected. The selected relay node will not be abandoned. Source node In determining to connect to another relay node After that, the previous relay node Remove it from the list.

[0060] In this embodiment of the invention, for step 5, if no source node can change the current selection during the selection of relay nodes, it indicates that the entire network has reached a stable solution, and the output is the final distributed many-to-one selection result.

[0061] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A many-to-one relay selection method for distributed networks, characterized in that, The method comprises the following steps: Step 1, constructing a relay network system model of a plurality of source nodes to a destination node, including a source node set , a relay node set , a destination node set ; Step 2, all source nodes in the network construct a relay node preference list; Each source node ranks the relay nodes according to the transmission rate, and the source node applies for connection according to the order of the relay nodes in the preference list, the relay node accepts all connection applications and feeds back the actual transmission rate that the source node can obtain, and ranks the source nodes according to the transmission rate to form a source node list; Step 3, all source nodes compare the current transmission rate with the transmission rate that can be achieved in the direct transmission mode; if the transmission rate that can be obtained by the current connection is lower than that in the direct transmission mode, the source node gives up the current relay connection and tries to select the next relay node in the preference list; Each source node that has not established a connection with a relay node updates the preference list until only the direct transmission mode can be selected; Step 4, relay node Randomly select a source node to establish connection with itself , source node Find a better relay node ; if the connection between the source node and the relay node can improve and the total transmission rate of the two relay nodes, the relay node accepts the application of the source node ; at the same time, the source node will be deleted from the source node list of the relay node connected Step 5, if the relay selection strategy of all source nodes cannot be changed in the selection process, it is indicated that the network has reached a stable solution, and the output is the final distributed many-to-one selection result; otherwise, steps 3-5 are cycled.

2. The many-to-one relay selection method for a distributed network of claim 1, wherein, In step 1, a relay network system model of multiple source nodes to one destination node is constructed, specifically: In the relay network, the source node applies for forwarding to the relay node to achieve spatial diversity, the relay node regularly broadcasts its own position information, and forwards the received signal to the destination node; the source node and the relay node select appropriate items in the opposite set according to their own selection criteria; There are N source nodes, M relay nodes and K destination nodes; wherein the source node set is: , the relay node set is: , and the destination node ; A source node is allowed to be connected with at most one relay node, and a relay node is simultaneously connected with multiple source nodes; For each source-relay node pair, the selection criterion for each source node is to find a relay node that can provide the maximum transmission rate, so as to achieve the respective transmission rate requirement; define the transmission rate of the relayed node source node of the service as: Relay node The transmission rate is: wherein, is an indicator function that equals 1 when the source node successfully connects to the relay node , , otherwise equals 0.

3. The many-to-one relay selection method for a distributed network of claim 1, wherein, In step 2, when multiple source nodes including the source node select the same relay node , the source node will share the relay link resource with other source nodes; source node according to the transmission rate , a preference list is constructed; wherein the real transmission rate available to the source node ; the preference list of ; this preference relation represents the source node the best choice is if rejected request, will make an application to the next relay node , and so on; denotes the unselected relay node; The relay node accepts all application source nodes according to the first-come-first-served principle, evenly allocates time resources, and rejects other source nodes; the rejected source node receives feedback, re-finds and applies for the next relay connection; similarly, the relay node feeds back the actual transmission rate that the received source node can obtain, and ranks the source nodes according to the transmission rate to form a source node list.

4. The many-to-one relay selection method for a distributed network of claim 3, wherein, The As the source node Real transmission rate that can be obtained: wherein denotes the number of source nodes accessing the relay node ; denotes the transmission rate transmitted by , forwarded and received; denotes the signal-to-noise ratio from the transmission of a source node to the reception at the relay node; denotes the signal-to-noise ratio from the transmission of a source node to the reception at the destination node; denotes the signal-to-noise ratio from the transmission of the relay node to the reception at the destination node; denotes the channel bandwidth; wherein denotes the transmission to the destination node with the assistance of the relay , whereas denotes the direct communication of the source node with the destination node 5. A many-to-one relay selection method for a distributed network as claimed in claim 3 or 4, characterized in that, In step 3, specifically: The source node updates the preference list in such a way that for each source node , the transmission rate when selecting a relay node is less than the transmission rate in direct mode, i.e. , , the current relay node is abandoned and the preference list is changed; until a relay node is found such that the transmission rate when going through the relay node is greater than or equal to the transmission rate in direct mode, i.e. , . Each source node that has not established a connection with a relay node updates the preference list until only the direct transmission mode can be selected; the source node that does not meet the requirement of replacing the relay node maintains the original relay node.

6. The many-to-one relay selection method for distributed network of claim 1, wherein, The step 4, for all source nodes connected to a relay node , randomly select one of them suggest it to find a better relay selection; when the source node approaches a new relay node , it will carry the transmission rate of the previous connected relay node , so that the relay node can compare the transmission rates and make a selection; If the source node Connecting relay nodes At that time, the source node The transmission efficiency is greater than that of the source node. Connecting relay nodes Transmission efficiency at that time, i.e. Then the source node To relay node Submit a connection request; if this option allows the relay node to... With relay node Total transmission rate If an additional relay node is added, the relay node will be added. Accept source node The application must be approved by the source node; otherwise, the application will be rejected. The selected relay node will not be abandoned. ;Source node In determining to connect to another relay node After that, the previous relay node Remove it from the list.

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