Method for constructing clusters of an aircraft ad-hoc network based on simultaneous and co-frequency full-duplex transmission

Abstract

The present invention provides a method for constructing clusters in an aircraft ad-hoc network based on simultaneous co-frequency full-duplex transmission, which includes the following steps: Before flight, perform pre-clustering on network nodes and bind pre-clustering information, and designate a cluster head node for each communication cluster, with the rest being cluster member nodes; each node is respectively equipped with a full-duplex signal transceiver with a dual-polarized antenna and capable of simultaneously demodulating multiple full-duplex signals and a set of half-duplex signal transceivers; after takeoff, each communication cluster sequentially uses full-duplex communication to construct an intra-cluster full-duplex communication link until all cluster member nodes establish full-duplex communication links with their cluster head nodes; at the same time, after each communication cluster completes the construction of intra-cluster communication, its cluster head node uses half-duplex communication to broadcast the clustering status information of its communication cluster and establish an inter-cluster half-duplex communication link. The present invention effectively improves the efficiency of constructing clusters of a large number of communication nodes by constructing an intra-cluster communication link through simultaneous co-frequency full-duplex and establishing an inter-cluster communication link using half-duplex.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft network communication, and particularly relates to a method for constructing a self-organizing network clustering of aircraft based on simultaneous and co-frequency full-duplex transmission. Background Art

[0002] In order to expand the network coverage and reduce the mutual interference between nodes, a hierarchical and clustering hybrid networking architecture is usually adopted for large-scale aircraft self-organizing networks. However, in traditional large-scale aircraft self-organizing networks, data transmission between nodes is carried out through time-division duplex, frequency-division duplex or half-duplex communication methods, and there are the following deficiencies: the utilization rate of network time-frequency transmission resources is relatively low, resulting in problems such as long network construction time for large-scale node hierarchical clustering networks and slow node access speed, which severely restricts the network information service capacity. Summary of the Invention

[0003] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, providing a method for constructing a self-organizing network clustering of aircraft based on simultaneous and co-frequency full-duplex transmission, significantly improving the network scale and data transmission rate, and reducing the node access time.

[0004] The technical solution of the present invention is:

[0005] A method for constructing a self-organizing network clustering of aircraft based on simultaneous and co-frequency full-duplex transmission includes the following steps:

[0006] (1) Before flight, the aircraft participating in communication networking are pre-clustered as network nodes, divided into multiple communication clusters each including one or more network nodes; in each communication cluster, a node is designated as the cluster head node, and the remaining nodes are cluster member nodes;

[0007] (2) Two sets of signal transceivers are respectively equipped for each network node, including a full-duplex signal transceiver for intra-cluster communication and a half-duplex signal transceiver for inter-cluster communication; the antenna of the full-duplex signal transceiver has two polarization modes of left-handed and right-handed; the full-duplex transceiver can simultaneously receive and demodulate multiple full-duplex signals;

[0008] (3) Pre-clustering information is loaded into each network node, including node type, node network ID number, node intra-cluster number, cluster sequence number, time slot allocation, and antenna polarization mode; the allocated time slots include intra-cluster network construction time slots and inter-cluster network construction time slots;

[0009] (4) After each aircraft takes off, the signal transceivers of each network node within the predetermined airspace range are turned on simultaneously, and the receiving antennas of the full-duplex signal transceivers and half-duplex signal transceivers of each network node are always in the receiving state; each communication node sets the antenna polarization mode of the full-duplex signal transceiver according to the pre-clustering information, so that full-duplex communication can be carried out between the cluster head node and the cluster member nodes, and full-duplex communication cannot be carried out between the cluster member nodes;

[0010] (5) Each communication cluster sequentially constructs the intra-cluster network according to the bound pre-clustering information according to the cluster sequence number: within the allocated intra-cluster network construction time slot of each communication cluster, the cluster head node and the cluster member nodes of the communication cluster use the full-duplex signal transceiver to perform information interaction and establish a full-duplex communication link; until all cluster member nodes have established full-duplex links with their respective cluster head nodes, the intra-cluster network construction is completed;

[0011] (6) While the intra-cluster network is being constructed, the cluster head nodes of the communication clusters that have completed the intra-cluster network construction broadcast the clustering status information of their communication clusters to all network nodes using the half-duplex signal transceiver according to the inter-cluster network construction time slot, and the remaining network nodes use the half-duplex signal transceiver to receive the clustering status information until all cluster head nodes of the communication clusters have completed the broadcast of the clustering status information, and the inter-cluster network construction is completed.

[0012] Preferably, in the step (5), within the allocated intra-cluster network construction time slot of each communication cluster, the cluster head node and the cluster member nodes of the communication cluster use the full-duplex signal transceiver to perform information interaction and establish a full-duplex communication link, specifically including:

[0013] The allocated intra-cluster network construction time slot of each communication cluster includes one or more full-duplex polling time slots;

[0014] Within each full-duplex polling time slot, the cluster head node simultaneously performs full-duplex information interaction with one or more cluster member nodes:

[0015] The cluster head node sends a cluster member search message using an omnidirectional beam through the full-duplex signal transceiver within each full-duplex polling time slot; the cluster member search message includes the pre-clustering information and node status information of the cluster head node, and the node status information includes spatial position information and motion speed information;

[0016] The cluster member node sends a cluster member join message using an omnidirectional beam through the full-duplex signal transceiver within its corresponding full-duplex polling time slot; the cluster member join message includes the pre-clustering information and node status information of the cluster member node;

[0017] After receiving the cluster member joining message from the cluster member nodes in the communication cluster, the cluster head node establishes a full-duplex communication link according to the pre-clustering information of the cluster member nodes, adds it to the cluster member list of the communication cluster, and records its status information;

[0018] After receiving the cluster member searching message from the cluster head node of the communication cluster, the cluster member node establishes a full-duplex communication link according to the pre-clustering information of the cluster head node and records its status information.

[0019] Preferably, in step (5), within the allocated time slot for building the intra-cluster network of each communication cluster, the cluster head node and the cluster member nodes of the communication cluster use a full-duplex signal transceiver to interact information and establish a full-duplex communication link, further including:

[0020] The cluster head node determines whether the cluster member belongs to the communication cluster according to the pre-clustering information in the received cluster member joining message. If it does not belong to the communication cluster, record its pre-clustering information and status information, do not establish a full-duplex communication link, and do not add it to the cluster member list of the communication cluster;

[0021] The cluster member node determines whether the cluster head node is the cluster head node of its communication cluster according to the pre-clustering information in the received cluster member searching message. If not, record its pre-clustering information and status information, and do not establish a full-duplex communication link.

[0022] Preferably, in step (4), each communication node sets the antenna polarization mode of the full-duplex signal transceiver according to the pre-clustering information, so that full-duplex communication can be carried out between the cluster head node and the cluster member nodes, and full-duplex communication cannot be carried out between the cluster member nodes: specifically: set the transmitting antenna and receiving antenna of the cluster head node to different polarization modes; set the receiving antenna of the cluster member node to the same polarization mode as the transmitting antenna of the cluster head node; set the transmitting antenna of the cluster member node to the same polarization mode as the receiving antenna of the cluster head node.

[0023] Preferably, the full-duplex signal transceivers of each network node operate in the same frequency band, the half-duplex signal transceivers of each network node operate in the same frequency band, and the full-duplex signal transceivers and half-duplex signal transceivers of each network node operate in different frequency bands.

[0024] Preferably, the communication clusters are divided into full - scale clusters, non - full - scale clusters, and isolated clusters according to the number of network nodes they contain: the number of network nodes in the full - scale cluster is equal to m*n + 1, and the node type of its cluster head node is a full - scale cluster head node; the number of network nodes in the non - full - scale cluster is greater than 1 and less than m*n + 1, and the node type of its cluster head node is a non - full - scale cluster head node; the number of network nodes in the isolated cluster is equal to 1, and the node type of its cluster head node is an isolated cluster head node; where m represents the number of full - duplex polling time slots within the full - scale cluster, and n represents the number of cluster member nodes that the cluster head node can simultaneously receive and demodulate information from.

[0025] Preferably, the clustering status information includes the pre - clustering information and status information of all network nodes in the communication cluster.

[0026] The advantages of the present invention compared with the prior art are as follows:

[0027] (1) Based on the hierarchical clustering network topology, combined with the dual - polarization characteristics of full - duplex nodes, a star - shaped network structure is adopted within the cluster network, and a full - duplex node grouping polling mechanism within the cluster is proposed, giving full play to the receiving and demodulating capabilities of the nodes and achieving wide - area coverage of a large number of nodes.

[0028] (2) Aiming at the characteristics of aircraft ad - hoc networks, according to the pre - injected clustering construction prior information, full - scale clusters, non - full - scale clusters, and isolated nodes complete node clustering in sequence, effectively avoiding co - channel interference between nodes during the clustering process and achieving reliable clustering of a large number of dual - polarization full - duplex nodes.

[0029] (3) Utilizing the advantages of the simultaneous co - channel full - duplex transmission technology, the cluster head and cluster member nodes simultaneously exchange "cluster member search" and "cluster member join" messages within the corresponding time slots. After node clustering is completed, a half - duplex link is used to broadcast the "clustering status" message to the entire network, reducing the time required for large - scale node clustering. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the full - duplex time slot allocation within the cluster in the embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the clustering process of dual - polarization full - duplex nodes in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] The following is a detailed description of the present invention, and the features and advantages of the present invention will become clearer and more definite with these descriptions.

[0033] The present invention provides a method for constructing aircraft ad - hoc network clustering based on simultaneous co - channel full - duplex transmission, which specifically includes:

[0034] In the ground pre-clustering stage, with the help of the powerful computing power of the networking center, referring to the constraints such as the total number of nodes actually participating in the networking, the number of network nodes within the cluster, the full-duplex communication distance, and the node location information, according to the grouping polling mechanism of dual-polarized full-duplex nodes within the cluster, after using the pre-clustering algorithm to complete the clustering of a large number of nodes, prior clustering information is generated, including node type, node network ID number, node number within the cluster, cluster serial number, time slot allocation, and antenna polarization mode control. After the execution of the clustering algorithm, the prior clustering information is injected into the aircraft nodes on the ground to facilitate the rapid network access of the nodes during flight.

[0035] Figure 1 For the case of n = 3 and m = 2, it shows the time slot allocation within the cluster in full-duplex mode, where n represents the reception and demodulation ability, and m represents the number of polling time slots within the cluster. This method is based on a hierarchical clustering self-organizing network architecture. Each cluster head node and its member nodes within the cluster form an intra-cluster network, and the cluster head nodes form an inter-cluster network. A single intra-cluster network includes 1 cluster head node and m * n cluster member nodes. The cluster head can simultaneously receive and demodulate information from n full-duplex cluster member nodes, that is, its reception and demodulation ability is n. The cluster head node transmits with a left-handed antenna and receives with a right-handed antenna (or transmits with a right-handed antenna and receives with a left-handed antenna). The antennas of the cluster member nodes use the opposite polarization mode, that is, transmit with a right-handed antenna and receive with a right-handed antenna (or transmit with a left-handed antenna and receive with a right-handed antenna). Due to the different polarization modes, the intra-cluster network is a star structure, and only the cluster head and the cluster member nodes conduct full-duplex communication. The cluster member nodes cannot conduct full-duplex communication during the clustering construction process. In addition, the intra-cluster uses time division multiple access mode. The cluster head conducts full-duplex communication with n cluster members in each time slot based on the grouping polling method. Due to the different antenna polarization modes of the cluster members, the cluster member nodes cannot conduct full-duplex communication during the clustering construction process. The full-duplex communication cycle within the cluster includes m polling time slots t1, t2, ……, tm, and the time slot length is ts. Figure 1 In the shown situation, the cluster head can simultaneously receive and demodulate the signals of 3 cluster members. The intra-cluster uses a grouping polling method with every 3 cluster members as a group. The full-duplex communication cycle is 2 * ts, including two time slots t1 and t2. In the t1 time slot, the cluster head node with the intra-cluster number 000 conducts full-duplex communication with the cluster member nodes with intra-cluster numbers 001 - 011. In the t2 time slot, the cluster head node with the intra-cluster number 000 conducts full-duplex communication with the cluster member nodes with intra-cluster numbers 100 - 110. The subsequent content of this specification takes Figure 1 the shown situation as an example to elaborate in detail on a method for constructing a cluster in an aircraft self-organizing network based on the simultaneous and co-frequency full-duplex transmission technology, but this method is not limited to Figure 1 the described situation.

[0036] Figure 2 For Figure 1In the shown scenario, it is a schematic diagram of the large-scale dual-polarization full-duplex node clustering process. After the ground pre-clustering is completed, the network node types can be divided into full-capacity cluster head nodes, non-full-capacity cluster head nodes, isolated cluster head nodes, and cluster member nodes. Since the nodes use omnidirectional antennas, in order to reduce the co-frequency interference during the clustering construction process, the network nodes turn on simultaneously after reaching a certain airspace range according to the predetermined trajectory, and according to the pre-injected cluster sequence numbers, they sequentially complete the node clustering according to the prior information of the clustering construction in order.

[0037] First of all, the full-capacity clusters perform node clustering in sequence according to the cluster sequence numbers. A full-capacity cluster includes 1 cluster head and 6 cluster member nodes, and the clustering process lasts for one full-duplex cycle. With the advantage of full-duplex communication, the two-way information interaction between the cluster head and a group of cluster members can be completed within one full-duplex time slot. In the t1 time slot, the full-capacity cluster head numbered 000 in the cluster sends a "cluster member search" message to the cluster members numbered 001 - 011 in the cluster, which is used to search for cluster members and inform them of the current status of the cluster head. In a specific embodiment, the data structure of the "cluster member search" is shown in Table 1.

[0038] Table 1 Data structure of the "cluster member search" message in the embodiment of the present invention

[0039]

[0040] In the same time slot, the cluster members numbered 001 - 011 in the cluster simultaneously send a "cluster member join" message to the cluster head, which is used to apply to join this cluster and inform the cluster head of the current status of this node. The data structure of the "cluster member join" is shown in Table 2.

[0041] Table 2 Data structure of the "cluster member join" message in the embodiment of the present invention

[0042]

[0043] After receiving the "cluster member search" message sent by the cluster head, the cluster member determines whether it belongs to this cluster according to the prior information of the clustering. If it is not a member of this cluster, it records the status information of the cluster head; if it is a member of this cluster, it confirms the existence of the cluster head and records the status information of the cluster head. After receiving multiple "cluster member join" messages sent by cluster members, the cluster head determines whether this node belongs to this cluster. If it is a member of this cluster, it adds it to the cluster member list and records the status information; if it is not a member of this cluster, it only records the status information but does not add it to the cluster member list. In the t2 time slot, the cluster head and the cluster members numbered 100 - 110 in the cluster exchange the "cluster member search" message and the "cluster member join" message, and the specific process is the same as that in the t1 time slot. If the number of full-capacity clusters is I, the time required for the full-capacity cluster node clustering is 2 * I * ts.

[0044] If there is a cluster member node that fails to establish inter-cluster communication with the cluster head node during the clustering time slot of a full-sized cluster, the cluster head node defaults that the node is destroyed and updates the cluster member list according to the cluster member nodes with established communication connections.

[0045] Secondly, after the full-sized cluster nodes complete clustering, the non-full-sized clusters perform node clustering in sequence according to the cluster serial numbers. If the number of cluster members in a non-full-sized cluster is x (x < m * n), then the number of time slots in the full-duplex cycle within the cluster is equal to the ceiling of x / n. In the case of n = 3 and m = 2, the number of cluster member nodes in a non-full-sized cluster is less than 6. If the number of cluster members is less than 3, then the clustering of this non-full-sized cluster only occupies 1 time slot. If the number of cluster members is more than 3 and less than 6, then the clustering of this non-full-sized cluster occupies 2 time slots. In addition, the process of node clustering in non-full-sized clusters is the same as that in full-sized clusters. If the number of non-full-sized clusters with less than 3 cluster members is L, and the number of non-full-sized clusters with more than 3 and less than 6 cluster members is K, then the time required for non-full-sized cluster clustering is (2 * K + L) * ts.

[0046] After the full-sized and non-full-sized cluster nodes complete clustering, the cluster head uses a half-duplex signal transceiver to broadcast the clustering status, broadcasting the "clustering status" message of this cluster to the entire network, which is used to inform the nodes in the whole network of the cluster member list and status information of this cluster. In a specific embodiment, the data structure of the "clustering status" message is shown in Table 3.

[0047] Table 3 Data structure of the "clustering status" message in the embodiment of the present invention

[0048]

[0049]

[0050] The half-duplex signal transceiver adopts a frequency hopping + spread spectrum low-speed and highly stealthy transmission waveform, and realizes long-distance inter-cluster information transmission based on a fast frequency hopping sequence and a high-gain spread spectrum code. The half-duplex signal transceiver and the full-duplex signal transceiver work in different frequency bands, so the two sets of signal transceivers can work simultaneously without mutual interference. The time slot length of the half-duplex signal transceiver is tp, and the node can broadcast the "clustering status" information to each node between clusters within a single time slot. The time required for the clustering status broadcast stage of full-sized and non-full-sized clusters is (K + I) * tp.

[0051] According to the above analysis of the clustering process, in Figure 1 the case of n = 3 and m = 2 as shown, based on two sets of signal transceivers of full-duplex within the cluster and half-duplex between clusters, the hierarchical and clustered flight self-organizing network can simultaneously complete the construction of intra-cluster and inter-cluster network clustering. The time required for full-sized and non-full-sized clusters to complete clustering is max((2 * K + L) * ts, (K + I) * tp), which improves the reliability of node access to the network and significantly reduces the construction time of a large-scale aircraft self-organizing network.

[0052] Finally, the isolated cluster heads form clusters. In extremely special cases, during the clustering phase, the position of a certain node cannot form a cluster with the remaining nodes, and only this isolated node serves as the cluster head to form a cluster. After the nodes in the full-sized clusters and the non-full-sized clusters form clusters, the isolated cluster heads use the half-duplex signal transceiver in sequence according to the cluster serial number to broadcast the "clustering status" message of their own clusters to the entire network.

[0053] The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A method for constructing clusters in an aircraft ad-hoc network based on simultaneous and co-frequency full-duplex transmission, characterized in that Including the following steps: (1) Before flight, pre - cluster the aircrafts participating in the communication network as network nodes, dividing them into multiple communication clusters each including one or more network nodes; in each communication cluster, designate one node as the cluster - head node and the remaining nodes as cluster - member nodes; (2) Equip each network node with two sets of signal transceivers, including a full - duplex signal transceiver for intra - cluster communication and a half - duplex signal transceiver for inter - cluster communication; the antenna of the full - duplex signal transceiver has two polarization modes, left - hand polarization and right - hand polarization; the full - duplex transceiver can simultaneously receive and demodulate multiple full - duplex signals; the full - duplex signal transceivers of each network node work in the same frequency band, the half - duplex signal transceivers of each network node work in the same frequency band, and the full - duplex signal transceivers and half - duplex signal transceivers of each network node work in different frequency bands; (3) Load the pre - clustering information to each network node, including node type, node network ID number, intra - cluster node number, cluster sequence number, time - slot allocation, and antenna polarization mode; the allocated time - slots include intra - cluster network construction time - slots and inter - cluster network construction time - slots; (4) After each aircraft takes off and reaches the predetermined airspace range, the signal transceivers of each network node are powered on simultaneously; Each communication node sets the antenna polarization mode of the full - duplex signal transceiver according to the pre - clustering information, so that full - duplex communication can be carried out between the cluster - head node and the cluster - member nodes, and full - duplex communication cannot be carried out between the cluster - member nodes; specifically: set the transmitting antenna and receiving antenna of the cluster - head node to different polarization modes; set the receiving antenna of the cluster - member node to the same polarization mode as the transmitting antenna of the cluster - head node; set the transmitting antenna of the cluster - member node to the same polarization mode as the receiving antenna of the cluster - head node; (5) Each communication cluster sequentially performs intra - cluster network construction according to the loaded pre - clustering information according to the cluster sequence number: within the allocated intra - cluster network construction time - slot of each communication cluster, the cluster - head node and the cluster - member nodes of this communication cluster use the full - duplex signal transceiver to perform information interaction and establish a full - duplex communication link, specifically including: The allocated intra - cluster network construction time - slot of each communication cluster includes one or more full - duplex polling time - slots; Within each full - duplex polling time - slot, the cluster - head node simultaneously performs full - duplex information interaction with one or more cluster - member nodes: The cluster - head node sends a cluster - member search message using an omnidirectional beam through the full - duplex signal transceiver within each full - duplex polling time - slot; the cluster - member search message contains the pre - clustering information and node status information of this cluster - head node, and the node status information includes spatial position information and motion speed information; The cluster - member node sends a cluster - member join message using an omnidirectional beam through the full - duplex signal transceiver within its corresponding full - duplex polling time - slot; the cluster - member join message includes the pre - clustering information and node status information of this cluster - member node; After the cluster - head node receives the cluster - member join message of the cluster - member nodes in this communication cluster, it establishes a full - duplex communication link according to the pre - clustering information of the cluster - member nodes, adds it to the cluster - member list of this communication cluster and records its status information; After receiving the cluster member search message from the cluster head node of the communication cluster, the cluster member node establishes a full-duplex communication link according to the pre-clustering information of the cluster head node and records its status information; All cluster member nodes establish full-duplex links with their respective cluster head nodes to complete the construction of the intra-cluster network; (6) While the intra-cluster network is being constructed, the cluster head node of the communication cluster that has completed the intra-cluster network construction broadcasts the clustering status information of this communication cluster to all network nodes using a half-duplex signal transceiver according to the inter-cluster network construction time slot. The remaining network nodes use half-duplex signal transceivers to receive the clustering status information until all cluster head nodes of the communication clusters have completed the broadcast of the clustering status information, and the inter-cluster network construction is completed.

2. The method for constructing a clustered structure of an aircraft ad-hoc network based on simultaneous co-frequency full-duplex transmission according to claim 1, characterized in that In step (5) above, within the allocated intra-cluster network construction time slot of each communication cluster, the cluster head node and the cluster member nodes of this communication cluster use full-duplex signal transceivers to interact information and establish a full-duplex communication link, further including: The cluster head node determines whether the cluster member belongs to this communication cluster according to the pre-clustering information in the received cluster member join message. If it does not belong to this communication cluster, record its pre-clustering information and status information, do not establish a full-duplex communication link, and do not add it to the cluster member list of this communication cluster; The cluster member node determines whether the cluster head node is the cluster head node of its communication cluster according to the pre-clustering information in the received cluster member search message. If not, record its pre-clustering information and status information and do not establish a full-duplex communication link.

3. The method for constructing clusters of an aircraft ad-hoc network based on simultaneous co-frequency full-duplex transmission according to claim 2, wherein The communication cluster is divided into a full-scale cluster, an under-full-scale cluster, and an isolated cluster according to the number of network nodes it contains: the number of network nodes in the full-scale cluster is equal to m*n + 1, and the node type of its cluster head node is a full-scale cluster head node; the number of network nodes in the under-full-scale cluster is greater than 1 and less than m*n + 1, and the node type of its cluster head node is an under-full-scale cluster head node; the number of network nodes in the isolated cluster is equal to 1, and the node type of its cluster head node is an isolated cluster head node; where m represents the number of full-duplex polling time slots within the full-scale cluster, and n represents the number of cluster member nodes that the cluster head node can receive and demodulate information simultaneously.

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