Communication networking mode based on directional antenna

Abstract

The invention discloses a communication networking mode based on a directional antenna. The communication networking mode mainly comprises time synchronization between nodes, directional communication maintenance, service data transmission and disconnection detection / re-access. The time synchronization adopts a two-way time synchronization algorithm, and synchronization information interaction is regularly carried out between nodes to realize high-precision time synchronization; the directional communication maintenance adopts a polling mode to carry out information interaction, and all interacted information needs to contain position information of a sender; the service data transmission is used for point-to-point information data transmission of the user node and the center node in the corresponding polling time slot; the disconnection detection / re-access is used for checking whether the user node can normally communicate in the corresponding time slot or not, and re-access is carried out if the user node cannot normally communicate. In the communication networking mode provided by the invention, directional antennas are used for bidirectionally transmitting signals among the nodes, so that timing synchronization, information transmission and disconnection detection / re-access among the nodes are realized.

Description

Technical Field

[0001] The present invention relates to the fields of wireless communications and antennas, and in particular to a communication networking method based on directional antennas. Background Art

[0002] Antennas are an important part of wireless communication networks as carriers for sending and receiving information. Antennas can be divided into omnidirectional antennas and directional antennas according to their directivity. In the omnidirectional antenna working mode, nodes send and receive signals in all directions, but there are defects such as power waste, interference with non-target neighboring nodes, and insufficient signal transmission distance. Directional antennas refer to antennas that focus energy in one beam direction through the action of array antennas, with almost no energy distribution in other directions.

[0003] Compared with omnidirectional antennas, using directional antennas for networking communications can limit the signal power within the coverage range of the main lobe, thereby avoiding interference with other nodes in the side lobe direction. Therefore, other nodes in the side lobe direction can also transmit in parallel. By increasing the number of parallel transmission links, the network throughput can be significantly improved. When nodes use directional antennas for networking communications, they can amplify the signal power, thereby improving the signal-to-noise ratio at the receiving node, and when the signal power is the same as that of an omnidirectional antenna, the directional antenna can convert the antenna gain into an extension of the communication distance, thereby expanding the communication range. In addition, using directional antennas for networking can reduce the probability of being eavesdropped by other nodes in the side lobe direction, thereby providing a safer communication method. Summary of the invention

[0004] In order to solve the problems of the prior art, the present invention designs a communication networking method based on directional antennas based on the advantages and disadvantages of omnidirectional antennas and directional antennas in networking, combined with the signal receiving and sending characteristics of directional antennas, to achieve high-precision time synchronization between nodes, directional communication maintenance, business data transmission, and loss detection / reaccess.

[0005] The present invention provides a communication networking method based on directional antennas, and the networking method includes: Time synchronization; Directed communications maintenance; Business data transmission; Loss of connection detection / reconnection.

[0006] Furthermore, the time synchronization adopts a two-way time synchronization algorithm, and the algorithm includes: The central node sends synchronization messages to the user nodes at a set synchronization interval and records the local sending timestamp T1; After receiving the synchronization message, the user node records the local receiving timestamp T2, and replies to the central node with a synchronization response message, recording the sending timestamp T3 of the synchronization response message; After receiving the synchronization response message, the central node records the local receiving timestamp T4; The central node sends a synchronization message to the user node again, which contains the timestamps T1 and T4 recorded by the central node; The user node uses the timestamp information T1~T4 to calculate the time deviation between the user node and the central node and correct the frequency offset and time offset of the local clock.

[0007] Furthermore, the directional communication maintenance uses a polling method to perform information interaction.

[0008] Furthermore, the information interaction includes the azimuth information of the transmitting end, so as to meet the requirement of the receiving end to maintain the radiation direction of the phased array antenna in real time.

[0009] Furthermore, the directional communication maintenance specifically includes that in each polling cycle, the central node sends polling information to the user nodes in sequence, and the data link layer of the central node signal needs to provide the azimuth information of each user node to its phased array antenna, so that the phased array antenna can switch the radiation direction in real time.

[0010] Furthermore, the service data transmission specifically includes point-to-point information transmission between the user node and the central node in the corresponding polling time slot.

[0011] Furthermore, the data packets in the business data transmission are segmented and fragmented by the LLC layer and the MAC layer of the communication protocol stack and the corresponding PDU header is added, and then delivered to the physical layer for transmission.

[0012] Furthermore, the loss of connection detection / re-access is used to check whether the user node can communicate normally in the corresponding time slot, and if it cannot communicate normally, re-access is performed.

[0013] Furthermore, the loss of connection detection / re-access uses an omnidirectional beam or a wide beam to continuously send loss of connection detection information in the time slot belonging to the user, and includes real-time location information of the central node.

[0014] On the other hand, the present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, it implements the steps of the above-mentioned communication networking method based on directional antennas.

[0015] Beneficial effects of the present invention: The communication networking method based on directional antennas provided by the present invention enables the central node and the user nodes to transmit information bidirectionally through directional antennas to perform time synchronization, directional communication maintenance, service data transmission, and loss detection / re-access, thereby realizing directional communication and timing synchronization between the central node and the user nodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention has the following accompanying drawings: Figure 1 The user node workflow in the communication networking mode based on directional antennas of the present invention; Figure 2 It is the central node working process in the communication networking mode based on directional antenna of the present invention; Figure 3 The timestamp acquisition process in the communication networking mode based on directional antenna of the present invention; Figure 4 The frame structure of the communication networking method based on directional antennas of the present invention; Figure 5 It is a PDU structure of a user node in the communication networking mode based on directional antennas of the present invention; Figure 6 It is the PDU structure of the central node in the communication networking mode based on directional antenna of the present invention; Figure 7 The present invention discloses a data packet segmentation and reassembly process in a communication networking method based on directional antennas. DETAILED DESCRIPTION

[0017] The following is combined with Figure 1-7 The present invention is described in further detail.

[0018] A networking method based on directional antennas, such as Figure 1 and Figure 2 As shown, it mainly includes four steps: time synchronization, directional communication maintenance, business data transmission and loss of connection detection / re-access.

[0019] The time synchronization adopts a two-way synchronization algorithm, and transmits time information through a directional antenna, which is used for node calibration of time offset and frequency offset.

[0020] In the specific implementation process, time synchronization is divided into two stages: coarse time synchronization and fine time synchronization. The timestamp acquisition process is as follows: Figure 3 Assume that the central node clock is the same as the real physical time, we can get: ; The coarse synchronization algorithm runs at the beginning of the synchronization process. and time offset The time offset is relatively large and the range is not easy to determine. It can be expressed as: ; The time offset between two adjacent synchronization processes can be expressed as: ; Therefore, the rough estimate of the frequency offset can be expressed as: ; The user node corrects the voltage-controlled crystal oscillator frequency based on the rough estimate of the frequency deviation to achieve coarse synchronization. After the coarse synchronization process, the clock offset and frequency deviation between the user node and the central node will be reduced to a small and easy-to-determine range. Without considering the relative motion of the nodes and the capture error, it can be obtained: ; Building a linear model ; in: is the Gaussian noise matrix.

[0021] The minimum variance unbiased estimator of can be expressed as: ; The user node can calculate based on the four sets of timestamps collected The minimum variance unbiased estimator of is used to correct the local clock and crystal oscillator frequency, thereby achieving high-precision time synchronization between user nodes and central nodes.

[0022] The directional communication maintenance is used for information exchange between the central node and the user nodes through polling.

[0023] In the specific implementation process, Figure 4 As shown, in each TDMA frame, the central node first sends polling information to the user nodes in sequence, and the data link layer of the central node needs to provide the azimuth information of each user node to its phased array antenna, and the phased array antenna of the central node changes the radiation direction in real time to align with the corresponding user node. Then, the user node sends response information to the central node in sequence, and the data link layer of each user node needs to provide the azimuth information of the central node to its phased array antenna in order to adjust the radiation direction of the antenna to align with the central node. The azimuth information of each user node is maintained in real time by the protocol stack of the central node, and the azimuth information of the central node is maintained in real time by each user node.

[0024] The service data transmission is used for user nodes and central nodes to perform point-to-point information transmission in corresponding polling time slots. Figure 5 and Figure 6 These are the PDU structures of the central node and the user node respectively. The PDU of the central node includes coarse synchronization, fine synchronization, header and data segment, and the PDU of the user node includes coarse synchronization, fine synchronization, header, data segment and protection interval.

[0025] In the specific implementation process, Figure 7As shown in the figure, the LLC layer of the sender first detects the data received from the application layer. If the length of the received data is greater than the capacity of a single MAC block, the LLC layer of the sender segments the data and then sends each segment of data to the receiver in sequence. The LLC layer of the receiver is always in a detection state. If a data segment arrives, it receives it and determines whether the data segment is the end segment. If the data segment is the end segment, the multiple segments are reassembled into a complete data packet and delivered to the application layer. Otherwise, the received data segments are stored and continue to wait for the subsequent data segments from the sender until all the data segments are received and then reassembled and delivered to the application layer.

[0026] The lost connection detection / re-access is used to check whether the user node can communicate normally in the corresponding time slot. If it cannot communicate normally, re-access is performed.

[0027] In the specific implementation process, after entering the loss detection / re-access process, the central node uses an omnidirectional beam or a wide beam to continuously send loss detection information in the time slot belonging to the user node. The loss detection information should contain the real-time location information of the central node. If the user node successfully receives the information, it can re-establish synchronization with the central node, and align the radiation direction of its phased array antenna with the central node according to the real-time location information contained in the loss detection information, and then send loss detection response information to the central node in the corresponding time slot. If the central node successfully receives the loss detection response information from the user node, it is deemed to be successfully re-accessed, and both parties enter the normal directional communication mode. Otherwise, the central node should continue to send the loss detection information in a loop until the user node successfully re-accesses and enters the normal directional communication mode.

[0028] The above implementation modes are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and deformations without departing from the essence and scope of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention. The scope of patent protection of the present invention should be limited by the claims.

[0029] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A communication networking method based on directional antennas, characterized in that: The networking methods include: Time synchronization; Directed communications maintenance; Business data transmission; Loss of connection detection / reconnection.

2. The communication networking method based on directional antenna according to claim 1, characterized in that: The time synchronization adopts a two-way time synchronization algorithm, and the algorithm includes: The central node sends synchronization messages to the user nodes at a set synchronization interval and records the local sending timestamp T1; After receiving the synchronization message, the user node records the local receiving timestamp T2, and replies to the central node with a synchronization response message, recording the sending timestamp T3 of the synchronization response message; After receiving the synchronization response message, the central node records the local receiving timestamp T4; The central node sends a synchronization message to the user node again, which contains the timestamps T1 and T4 recorded by the central node; The user node uses the timestamp information T1~T4 to calculate the time deviation between the user node and the central node and correct the frequency offset and time offset of the local clock.

3. The communication networking method based on directional antenna according to claim 1, characterized in that: The directional communication maintenance adopts a polling method to perform information interaction.

4. The communication networking method based on directional antenna according to claim 2, characterized in that: The information interaction includes the azimuth information of the transmitting end, so as to meet the requirement of the receiving end to maintain the radiation direction of the phased array antenna in real time.

5. The communication networking method based on directional antenna according to claim 3, characterized in that: The directional communication maintenance specifically includes that in each polling cycle, the central node sends polling information to the user nodes in sequence, and the data link layer of the central node signal needs to provide the azimuth information of each user node to its phased array antenna, so that the phased array antenna can switch the radiation direction in real time.

6. The communication networking method based on directional antenna according to claim 1, characterized in that: The service data transmission specifically includes point-to-point information transmission between the user node and the central node in the corresponding polling time slot.

7. The communication networking method based on directional antenna according to claim 6, characterized in that: The data packets in the business data transmission are segmented and fragmented by the LLC layer and the MAC layer of the communication protocol stack and the corresponding PDU headers are added before being delivered to the physical layer for transmission.

8. The communication networking method based on directional antenna according to claim 1, characterized in that: The lost connection detection / re-access is used to check whether the user node can communicate normally in the corresponding time slot. If it cannot communicate normally, re-access is performed.

9. The communication networking method based on directional antenna according to claim 8, characterized in that: The loss of connection detection / re-access adopts an omnidirectional beam or a wide beam to continuously send loss of connection detection information in the time slot belonging to the user, and includes the real-time location information of the central node.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the communication networking method based on directional antennas described in any one of claims 1 to 9 are implemented.

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