Fast networking method for phased array antenna communication system without position information

Abstract

This invention discloses a rapid network establishment method for a phased array antenna communication system without location information. Specifically, it includes: omnidirectional spherical beam configuration of the phased array antenna: all antenna elements adopt U-slot rectangular single-feed patch antennas, and the beam formed by the antenna array surface is beamformed in the horizontal and elevation planes; spread spectrum low-speed data waveform network entry design: a network entry spread spectrum waveform design based on CDMA is adopted, using the spread spectrum sequence to modulate the latitude and longitude location information containing only 64 bits, thus widening the signal bandwidth transmission; the frame structure adopted includes fixed time slots for omnidirectional beam broadcast network entry communication and dynamic time slots for directional beam service communication; during the network establishment phase, the initiating node achieves omnidirectional communication by configuring the antenna beam and broadcasts network entry invitation information to neighboring location nodes, while other nodes configure directional communication to assist omnidirectional communication network entry. Nodes within a 1-hop communication range can complete rapid network establishment within 1 second, and the network is stable and reliable.

Description

Technical Field

[0001] This invention relates to the field of electronic communication technology, and in particular to a rapid network establishment method for a phased array antenna communication system without location information. Background Technology

[0002] For communication systems using phased array antennas, when there is no location information, active phased array antennas are often configured as directional high-gain, narrow-beam modes to obtain high gain and achieve long-distance communication coverage when several members distributed in space are to be connected into a decentralized network. However, due to the narrow beamwidth of a single beam and the directional nature of the beam coverage, it is impossible to simultaneously communicate with multiple members distributed in space, thus limiting the construction of directional beam networks.

[0003] In such networking applications, narrow beam scanning communication is usually used. Since each narrow beam has a dwell time, narrow beam scanning requires a lot of time to achieve spherical beam coverage, resulting in a long network establishment time, usually reaching the minute level. Summary of the Invention

[0004] The purpose of this invention is to provide a rapid network construction method for a phased array antenna communication system without location information. By configuring the phased array antennas of each node into a low-gain omnidirectional beam pattern during the network entry phase, and using a low-speed data transmission network entry waveform design, the method transmits network entry invitation broadcast information containing only geographical location information, thereby achieving rapid network construction.

[0005] The technical solution to achieve the purpose of this invention is: a rapid network establishment method for a phased array antenna communication system without location information, comprising:

[0006] Omnidirectional spherical beam configuration of phased array antenna: The array of an active phased array antenna includes multiple antenna elements. Each antenna element adopts a U-shaped slot rectangular single-feed patch antenna. Each antenna element corresponds to an amplitude and phase adjustment device. By adjusting the amplitude and phase control parameters of each channel, the beam formed by the antenna array is beamformed in the horizontal and elevation planes.

[0007] Spread spectrum low-speed data waveform network access design: The network access spread spectrum waveform design based on CDMA is adopted. The spread spectrum sequence is used to modulate the latitude and longitude high position information containing only 64 bits, thus widening the signal bandwidth transmission. The frame structure adopted has fixed time slots for omnidirectional beam broadcast network access communication and dynamic time slots for directional beam service communication.

[0008] Network construction design: During the network construction phase, the node initiating the network construction achieves omnidirectional communication by configuring antenna beams and broadcasts network access invitation information to neighboring nodes. Other nodes configure directional communication to assist omnidirectional communication for network access. Nodes within the 1-hop communication range can complete rapid network construction within 1 second. During the 2-hop neighbor discovery phase, the status and location information of network nodes that have already joined the network are announced through the network omnidirectional broadcast time slot. Neighbor discovery is completed by exchanging information directly through directional communication links, and then the network access is completed according to the process.

[0009] Furthermore, the phased array antenna is configured with an omnidirectional spherical beam, wherein:

[0010] An aerial installation platform requires two semi-circular arrays or four planar arrays to achieve omnidirectional spherical beam coverage, while a ground installation platform requires one elliptical array or three planar arrays to achieve omnidirectional hemispherical beam coverage.

[0011] The single-feed patch antenna uses coaxial pin feeding, feeding energy into the microstrip square patch on the dielectric substrate through the pins of the SSMP connector at the output end of the transmitting component, and uses a U-shaped slot to broaden the operating frequency.

[0012] The ground-based elliptical antenna has 256 array elements, and a single antenna can achieve hemispherical beam coverage of 360° horizontally and 0–90° elevation. The airborne semicircular array has 128 array elements, and two antennas can achieve omnidirectional spherical beam coverage of 360° horizontally and ±60° elevation.

[0013] Furthermore, the spread spectrum low-speed data waveform network access design includes a spread spectrum design, as detailed below:

[0014] During the network pre-planning phase before node networking, the spreading code allocation table is imported into the system devices. The spreading code allocation table records the unified broadcast spreading codeword for network initialization and the spreading codeword information of each node. The spreading code allocated to each node is unique across the entire network.

[0015] During the network access and network initialization phases, the virtual central node initiating network establishment or the network uses a unified spreading code to broadcast, ensuring that all nodes already in the network and those not yet in the network can correctly identify the broadcast HELLO packet. After receiving the broadcast network access invitation, nodes not yet in the network reply with their respective spreading codes to request network access. Nodes already in the network that do not participate in communication use the spreading codes in the allocation table to scan and receive network access requests, enabling nodes in the network to receive network access requests.

[0016] Furthermore, the 64-bit information transmitted in the network broadcast frame is encoded in quarters and modulated using QPSK to form 128 symbols. A synchronization sequence is inserted to generate 257 modulation symbols. Each modulation symbol is spread symbol by symbol using a spreading sequence with a length of 3000.

[0017] Furthermore, the design for spreading low-speed data waveforms to enter the network includes frame structure design, as detailed below:

[0018] The waveform frame structure uses one superframe every 1 second, and each superframe is divided into 128 subframes. Each subframe occupies a time length of 7.8125ms, and the guard time slot length is 500us, which is used for antenna beam switching time and air transmission delay.

[0019] Furthermore, the waveform frame structure is as follows:

[0020] The 1st and 65th frames are forward broadcast frames. Broadcast frames can only send location coordinate information, with a maximum transmission of 64 bits. For broadcast frames, the antenna transmits and receives in all directions. In the frame structure design, broadcast frames are designed to occupy two time slots to transmit 64 bits of effective data.

[0021] Frames 16 and 70 are reverse response frames. The maximum transmission length of a response frame is 384 bits. For response frames, the antenna transmits in a directional manner and receives in an omnidirectional manner. Compared with broadcast frames, the waveform has a higher channel rate. The response frame structure is specially designed to occupy a short time slot.

[0022] The 19th and 73rd frames are acknowledgment frames, with a maximum transmission length of 3200 bits. For acknowledgment frames, the antenna transmits omnidirectionally and receives directionally. The channel rates of the acknowledgment and response frame waveforms are consistent, occupying a long time slot.

[0023] Furthermore, the first time slot for network access is used for broadcasting, the new node responds to the network access request in the 16th time slot, and the node that sent the broadcast sends an acknowledgment frame in the 19th time slot. These three frames are dedicated timing sequences for network access control.

[0024] Other time slots in the frame structure are network protocol and service communication frames, which are dynamically allocated. The antenna transmits and receives in a directional manner, and different waveforms are selected for transmission according to the service. The highest rate is 64Mbps and the lowest rate is 8Mbps. The data transmission rate is adjusted by different spreading ratios, and the receiving end receives the data at an adaptive rate.

[0025] Furthermore, in the network design, wherein:

[0026] During the network construction phase, the start time of the network initialization phase of each node is different. Nodes establish links with other nodes by listening to omnidirectional channels or sending broadcast location messages. As long as a connection can be established with any node, it is considered that the network is necessary and possible to be established.

[0027] After any node powers on, it first listens for several frames. If it receives a location message broadcast by another node in the first time slot, it replies with a network topology message in the specified time slot, and the physical layer uses spread spectrum to resolve conflicts. If no message is received after listening, it broadcasts a location message omnidirectionally at low speed in the first time slot and initiates a network access invitation. After receiving the network access invitation, other powered-on nodes choose to reply with an omnidirectional or directional network access request based on the distance, and the physical layer uses spread spectrum to resolve conflicts. If a broadcast location message is received in the first time slot, it replies after several time slots due to the limitations of signal processing delay and propagation delay.

[0028] Furthermore, the location message contains no more than 72 bits of valid data, including the node's 8-bit ID number and 64-bit coordinates. After receiving this location message, neighboring nodes within a one-hop range will know the broadcast node's exact coordinates. The network topology message not only contains the node's ID number and location coordinates, but also the ID numbers and location coordinates of the one-hop neighbor nodes that the node has discovered. Nodes announce the known network topology through omnidirectional or directional transmission. After receiving the network topology message, the broadcast node obtains the locations of other nodes, preparing for further neighbor discovery handshakes.

[0029] Furthermore, after the network is established, network nodes operate in directional transmit / receive mode in other time slots. Nodes communicate the network topology to each other and start timers. When the timer expires, if the network topology has not changed, the network enters the normal communication phase.

[0030] Compared with the prior art, the significant advantages of this invention are:

[0031] (1) Spread spectrum communication technology is used to transmit low-speed network access broadcast information. The spread spectrum processing gain is used to compensate for the gain loss of the phased array antenna configured as an omnidirectional beam relative to the directional beam. This makes the single-hop maximum communication distance coverage capability of the omnidirectional beam low-speed network access mode and the directional beam high-speed service mode basically the same, ensuring the stability of the network access communication link. In the absence of geographical location, the network can be established quickly and reliably. All nodes within the one-hop communication range can complete the network construction within 1 second, and the network is stable and reliable.

[0032] (2) The frame structure design adopted allocates both fixed time slots for omnidirectional beam broadcast network access communication and dynamic time slots for directional beam service communication, allowing network nodes to quickly enter and exit the network, which greatly improves the flexibility and robustness of the network.

[0033] (3) It can be used for the development of Ku-band image data transmission communication systems. After testing and verification, its performance is reliable. Attached Figure Description

[0034] Figure 1This is a top view of a U-shaped slot rectangular single-feed patch antenna.

[0035] Figure 2 This is a side view of a U-shaped slot rectangular single-feed patch antenna.

[0036] Figure 3 This is diagram S11 of a U-shaped slot rectangular microstrip patch antenna element.

[0037] Figure 4 This is the E-plane radiation pattern of a 16GHz antenna element.

[0038] Figure 5 This is the H-plane radiation pattern of a 16GHz antenna element.

[0039] Figure 6 This is a schematic diagram of the broadcast frame structure design.

[0040] Figure 7 This is a schematic diagram of the frame structure design. Detailed Implementation

[0041] The rapid network construction design of the communication system based on phased array antennas in this invention is achieved by configuring the phased array antennas of each node into a low-gain omnidirectional beam pattern during the network access phase, adopting a low-speed data transmission network access waveform design, and transmitting network access invitation broadcast information containing only geographical location, thereby realizing rapid network construction of the system.

[0042] This invention uses spread spectrum communication technology to transmit low-speed network access broadcast information. It utilizes the spread spectrum processing gain to compensate for the gain loss of the phased array antenna configured as an omnidirectional beam relative to the directional beam, so that the single-hop maximum communication distance coverage capability of the omnidirectional beam low-speed network access mode and the directional beam high-speed service mode is basically the same, ensuring the stability of the network access communication link and achieving fast and reliable network establishment even without geographical location.

[0043] This invention provides a rapid network establishment method for a phased array antenna communication system without location information, comprising:

[0044] Omnidirectional spherical beam configuration of phased array antenna: The array of an active phased array antenna includes multiple antenna elements. Each antenna element adopts a U-shaped slot rectangular single-feed patch antenna. Each antenna element corresponds to an amplitude and phase adjustment device. By adjusting the amplitude and phase control parameters of each channel, the beam formed by the antenna array is beamformed in the horizontal and elevation planes.

[0045] Spread spectrum low-speed data waveform network access design: The network access spread spectrum waveform design based on CDMA is adopted. The spread spectrum sequence is used to modulate the latitude and longitude high position information containing only 64 bits, thus widening the signal bandwidth transmission. The frame structure adopted has fixed time slots for omnidirectional beam broadcast network access communication and dynamic time slots for directional beam service communication.

[0046] Network construction design: During the network construction phase, the node initiating the network construction achieves omnidirectional communication by configuring antenna beams and broadcasts network access invitation information to neighboring nodes. Other nodes configure directional communication to assist omnidirectional communication for network access. Nodes within the 1-hop communication range can complete rapid network construction within 1 second. During the 2-hop neighbor discovery phase, the status and location information of network nodes that have already joined the network are announced through the network omnidirectional broadcast time slot. Neighbor discovery is completed by exchanging information directly through directional communication links, and then the network access is completed according to the process.

[0047] As one specific implementation, the phased array antenna is configured with an omnidirectional spherical beam, wherein:

[0048] An aerial installation platform requires two semi-circular arrays or four planar arrays to achieve omnidirectional spherical beam coverage, while a ground installation platform requires one elliptical array or three planar arrays to achieve omnidirectional hemispherical beam coverage.

[0049] The single-feed patch antenna uses coaxial pin feeding, feeding energy into the microstrip square patch on the dielectric substrate through the pins of the SSMP connector at the output end of the transmitting component, and uses a U-shaped slot to broaden the operating frequency.

[0050] The ground-based elliptical antenna has 256 array elements, and a single antenna can achieve hemispherical beam coverage of 360° horizontally and 0–90° elevation. The airborne semicircular array has 128 array elements, and two antennas can achieve omnidirectional spherical beam coverage of 360° horizontally and ±60° elevation.

[0051] As one specific implementation, the spread spectrum low-speed data waveform network access design includes a spread spectrum design, as detailed below:

[0052] During the network pre-planning phase before node networking, the spreading code allocation table is imported into the system devices. The spreading code allocation table records the unified broadcast spreading codeword for network initialization and the spreading codeword information of each node. The spreading code allocated to each node is unique across the entire network.

[0053] During the network access and network initialization phases, the virtual central node initiating network establishment or the network uses a unified spreading code to broadcast, ensuring that all nodes already in the network and those not yet in the network can correctly identify the broadcast HELLO packet. After receiving the broadcast network access invitation, nodes not yet in the network reply with their respective spreading codes to request network access. Nodes already in the network that do not participate in communication use the spreading codes in the allocation table to scan and receive the broadcast network access invitation information, enabling nodes in the network to receive the network access request.

[0054] In one specific implementation, the 64-bit information transmitted in the network broadcast frame is encoded in 1 / 4 and modulated by QPSK to form 128 symbols. A synchronization sequence is inserted to generate 257 modulation symbols. Each modulation symbol is spread symbol by symbol using a spreading sequence with a length of 3000.

[0055] As one specific implementation, the spread spectrum low-speed data waveform network access design includes frame structure design, as detailed below:

[0056] The waveform frame structure uses one superframe every 1 second, and each superframe is divided into 128 subframes. Each subframe occupies a time length of 7.8125ms, and the guard time slot length is 500us, which is used for antenna beam switching time and air transmission delay.

[0057] As one specific implementation method, the waveform frame structure is as follows:

[0058] The 1st and 65th frames are forward broadcast frames. Broadcast frames can only send location coordinate information, with a maximum transmission of 64 bits. For broadcast frames, the antenna transmits and receives in all directions. In the frame structure design, broadcast frames are designed to occupy two time slots to transmit 64 bits of effective data.

[0059] Frames 16 and 70 are reverse response frames. The maximum transmission length of a response frame is 384 bits. For response frames, the antenna transmits in a directional manner and receives in an omnidirectional manner. Compared with broadcast frames, the waveform has a higher channel rate. The response frame structure is specially designed to occupy a short time slot.

[0060] The 19th and 73rd frames are acknowledgment frames, with a maximum transmission length of 3200 bits. For acknowledgment frames, the antenna transmits omnidirectionally and receives directionally. The channel rates of the acknowledgment and response frame waveforms are consistent, occupying a long time slot.

[0061] In one specific implementation, the first time slot for network access is used for broadcasting, the new node responds to the network access request in the 16th time slot, and the node that sent the broadcast sends an acknowledgment frame in the 19th time slot. These three frames are dedicated timing sequences for network access control.

[0062] Other time slots in the frame structure are network protocol and service communication frames, which are dynamically allocated. The antenna transmits and receives in a directional manner, and different waveforms are selected for transmission according to the service. The highest rate is 64Mbps and the lowest rate is 8Mbps. The data transmission rate is adjusted by different spreading ratios, and the receiving end receives the data at an adaptive rate.

[0063] As one specific implementation method, the network construction design includes:

[0064] During the network construction phase, the start time of the network initialization phase of each node is different. Nodes establish links with other nodes by listening to omnidirectional channels or sending broadcast location messages. As long as a connection can be established with any node, it is considered that the network is necessary and possible to be established.

[0065] After any node powers on, it first listens for several frames. If it receives a location message broadcast by another node in the first time slot, it replies with a network topology message in the specified time slot, and the physical layer uses spread spectrum to resolve conflicts. If no message is received after listening, it broadcasts a location message omnidirectionally at low speed in the first time slot and initiates a network access invitation. After receiving the network access invitation, other powered-on nodes choose to reply with an omnidirectional or directional network access request based on the distance, and the physical layer uses spread spectrum to resolve conflicts. If a broadcast location message is received in the first time slot, it replies after several time slots due to the limitations of signal processing delay and propagation delay.

[0066] In one specific implementation, the location message contains no more than 72 bits of valid data, including the node's 8-bit ID number and 64-bit coordinates. After receiving this location message, neighboring nodes within a one-hop range know the exact coordinates of the broadcast node. The network topology message not only contains the node's ID number and coordinates but also the ID numbers and coordinates of the one-hop neighbor nodes that the node has discovered. The node announces its known network topology through omnidirectional or directional transmission. After receiving the network topology message, the broadcast node obtains the locations of other nodes, preparing for further neighbor discovery handshakes.

[0067] As one specific implementation method, after the network is established, network nodes operate in directional transmit / receive antenna mode in other time slots. Nodes announce the network topology to each other and start timers. When the timer expires, if there is no change in the network topology, the normal communication phase begins.

[0068] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0069] Example

[0070] The present invention provides a rapid network establishment method for a phased array antenna communication system without location information. The specific implementation process is as follows:

[0071] ① Omnidirectional spherical beam configuration of phased array antenna

[0072] An active phased array antenna consists of multiple antenna elements, each corresponding to an amplitude and phase adjustment device. By adjusting the amplitude and phase control parameters of each device, the beamform formed by the antenna array is beamformed in the horizontal and elevation planes. Generally, aerial installation platforms require two semi-circular arrays or four planar arrays to achieve omnidirectional spherical beam coverage, while ground installation platforms require one elliptical array or three planar arrays to achieve omnidirectional hemispherical beam coverage.

[0073] The phased array antennas of this invention all employ U-slot rectangular single-feed patch antennas. These single-feed patch antennas are fed via coaxial pins, and energy is fed into a microstrip square patch on a dielectric substrate through the pins of the SSMP connector at the output end of the transmitting component. The U-slot design broadens the operating frequency, resulting in a wider beam angle and bandwidth. The ground-based elliptical antenna has 256 elements, achieving 360° horizontal and 0–90° elevation hemispherical beam coverage with a single antenna. The airborne semi-circular array has 128 elements, with two antennas achieving 360° horizontal and ±60° elevation omnidirectional spherical beam coverage with two antennas. Figure 1 , Figure 2 These are top and side views of a U-shaped slot rectangular single-feed patch antenna element. Figure 3 This is a simulation diagram of the S11 U-shaped slot rectangular single-feed patch antenna. Figure 4 , Figure 5 This is the horizontal and elevation pattern of a U-shaped slot rectangular single-feed patch antenna.

[0074] ② Spread spectrum low-speed data waveform network access design

[0075] This invention employs a CDMA-based network access spread spectrum waveform design, utilizing a spread spectrum sequence to modulate latitude and longitude information, which contains only 64 bits, thereby widening the signal bandwidth for transmission. This improves the low interception and low detection performance of nodes on one hand, and on the other hand, it considers potential contention-driven concurrent packet collisions during network access or concurrent packets during network operation to improve the efficiency of time slot utilization.

[0076] a) Spread spectrum design

[0077] During the network pre-planning phase before node networking, the spreading code allocation table is imported into the system devices. The spreading code allocation table records the unified broadcast spreading codeword for network initialization and the spreading codeword information for each node. The spreading code assigned to each node is unique across the entire network.

[0078] During the network access and network initialization phases, the virtual central node initiating network establishment or the network uses a unified spreading code to broadcast, ensuring that all nodes already in the network and those not yet in the network can correctly identify the broadcast HELLO packet. After receiving the broadcast network access invitation, nodes not yet in the network reply with their own spreading codes to request network access. Nodes already in the network that do not participate in communication scan and receive the information using the spreading codes in the allocation table, thus ensuring that nodes in the network can receive the network access request.

[0079] The 64-bit information transmitted in the network access broadcast frame is 1 / 4 encoded and QPSK modulated to form 128 symbols. A synchronization sequence is inserted, generating 257 modulation symbols. Each modulation symbol is spread symbol-by-symbol using a spreading sequence of length 3000. The network access broadcast frame structure is designed as follows: Figure 6 As shown

[0080] b) Frame structure design

[0081] Frame structure design such as Figure 7 As shown, the waveform frame structure is divided into 128 subframes, with each subframe occupying a time length of 7.8125ms. The guard time slot length is 500us, which is used for antenna beam switching time and air transmission delay.

[0082] The 1st and 65th frames are forward broadcast frames. Broadcast frames can only send the simplest location coordinate information, with a maximum transmission of 64 bits. For broadcast frames, the antenna transmits and receives in all directions, resulting in a very low channel rate for the waveform. Therefore, a dedicated broadcast frame design is used in the frame structure design. The broadcast frame design occupies two time slots and transmits only 64 bits of effective data.

[0083] Frames 16 and 70 are reverse response frames, and a response frame can transmit up to 384 bits. For response frames, the antenna transmits directionally and receives omnidirectionally. Compared to broadcast frames, the channel rate of the waveform is increased, and the frame structure is specially designed to occupy a short time slot.

[0084] Frames 19 and 73 are acknowledgment frames, and a maximum of 3200 bits can be transmitted for each acknowledgment frame. For acknowledgment frames, the antenna transmits omnidirectionally and receives directionally. The channel rate of the acknowledgment frame and the response frame waveform are the same, occupying a long time slot.

[0085] The first time slot for network access is used for broadcasting. New nodes respond to network access requests in the 16th time slot, and nodes that send broadcasts send confirmation frames in the 19th time slot. These three frames are dedicated timing sequences for network access control.

[0086] Other time slots in the frame structure are network protocol and service communication frames, which are dynamically allocated. The antenna transmits and receives in a directional manner, and different waveforms are selected for transmission according to the service. The highest rate is 64Mbps and the lowest rate is 8Mbps. The data transmission rate is adjusted by different spreading ratios, and the receiving end receives the data at an adaptive rate.

[0087] ③ Network design

[0088] During the network construction phase, the node initiating the network construction achieves omnidirectional communication by configuring antenna beams and broadcasts network access invitation information to neighboring nodes. Other nodes configure directional communication to assist omnidirectional communication for rapid network access. Nodes within the 1-hop communication range can complete rapid network construction within 1 second. During the two-hop neighbor discovery phase, the status and location information of network nodes that have already joined the network are announced through the network omnidirectional broadcast time slot. Neighbor discovery is completed by exchanging information directly through directional communication links, and then the network access is completed according to the process.

[0089] During network construction, since each node's power-on time or required network access time is different, the start time of each node's network initialization phase is also different. Nodes establish links with other nodes by omnidirectional listening channels or by sending broadcast location messages. As long as a connection can be established with any node, the network is considered necessary and possible to establish. Specifically, after any node powers on, it first listens for several frames. If it receives a location message broadcast by another node in the first time slot, it replies with a network topology message in the specified time slot, and the physical layer uses spread spectrum to resolve collisions. If no message is received after listening, it broadcasts a location message omnidirectionally at low speed in the first time slot, initiating a network access invitation. Other powered-on nodes, upon receiving the invitation, choose to reply with an omnidirectional or directional network access request based on distance, and the physical layer uses spread spectrum to resolve collisions. The reason for the interval of several time slots between receiving a broadcast location message in the first time slot is to account for the limitations of signal processing and propagation delays.

[0090] Location messages contain no more than 72 bits of valid data, including an 8-bit ID and 64-bit coordinates of the broadcast node. Upon receiving this location message, neighboring nodes within a one-hop radius know the broadcast node's precise coordinates. Network topology messages include not only the broadcast node's ID and coordinates but also the IDs and coordinates of its discovered one-hop neighbors. Nodes announce their known network topology through omnidirectional or targeted transmissions. Upon receiving a network topology message, a broadcast node can learn the locations of other nodes, preparing for further neighbor discovery handshakes.

[0091] After the network is established, network nodes operate in directional transmit / receive mode in other time slots. Nodes announce the network topology to each other and start timers. When the timer expires, if the network topology has not changed, the network enters the normal communication phase.

[0092] This invention solves the problem of rapid network construction in high-speed data communication systems based on phased array antennas under conditions of no location information. It enables all nodes within a one-hop communication range to complete network construction within 1 second, ensuring network stability and reliability. The frame structure design allocates both fixed time slots for omnidirectional beamcast network entry communication and dynamic time slots for directional beam service communication, allowing network nodes to quickly join and leave the network, greatly improving network flexibility and robustness. Furthermore, this invention has been applied to the development of a Ku-band image data transmission communication system, and has undergone testing and verification, demonstrating reliable performance.

Claims

1. A rapid network establishment method for a phased array antenna communication system without location information, characterized in that, include: Omnidirectional spherical beam configuration of phased array antenna: The array of an active phased array antenna includes multiple antenna elements. Each antenna element adopts a U-shaped slot rectangular single-feed patch antenna. Each antenna element corresponds to an amplitude and phase adjustment device. By adjusting the amplitude and phase control parameters of each channel, the beam formed by the antenna array is beamformed in the horizontal and elevation planes. Spread spectrum low-speed data waveform network access design: The network access spread spectrum waveform design based on CDMA is adopted. The spread spectrum sequence is used to modulate the latitude and longitude high position information containing only 64 bits, thus widening the signal bandwidth transmission. The frame structure adopted has fixed time slots for omnidirectional beam broadcast network access communication and dynamic time slots for directional beam service communication. Network construction design: During the network construction phase, the node initiating the network construction achieves omnidirectional communication by configuring antenna beams and broadcasts network access invitation information to neighboring nodes. Other nodes configure directional communication to assist omnidirectional communication for network access. Nodes within the 1-hop communication range can complete rapid network construction within 1 second. During the 2-hop neighbor discovery phase, the status and location information of network nodes that have already joined the network are announced through the network omnidirectional broadcast time slot. Neighbor discovery is completed by exchanging information directly through directional communication links, and then the network access is completed according to the process.

2. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 1, characterized in that, The phased array antenna is configured with an omnidirectional spherical beam, wherein: An aerial installation platform requires two semi-circular arrays or four planar arrays to achieve omnidirectional spherical beam coverage, while a ground installation platform requires one elliptical array or three planar arrays to achieve omnidirectional hemispherical beam coverage. The single-feed patch antenna uses coaxial pin feeding, feeding energy into the microstrip square patch on the dielectric substrate through the pins of the SSMP connector at the output end of the transmitting component, and uses a U-shaped slot to broaden the operating frequency. The ground-based elliptical antenna has 256 array elements, and a single antenna can achieve hemispherical beam coverage of 360° horizontally and 0–90° elevation. The airborne semicircular array has 128 array elements, and two antennas can achieve omnidirectional spherical beam coverage of 360° horizontally and ±60° elevation.

3. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 1, characterized in that, The spread spectrum low-speed data waveform network access design includes spread spectrum design, as detailed below: During the network pre-planning phase before node networking, the spreading code allocation table is imported into the system devices. The spreading code allocation table records the unified broadcast spreading codeword for network initialization and the spreading codeword information of each node. The spreading code allocated to each node is unique across the entire network. During the network access phase and network initialization phase, the virtual central node that initiates network establishment or the network uses a network-wide unified spreading code to broadcast, ensuring that all nodes that have joined the network and those that have not joined the network can correctly identify the broadcast HELLO packet; After receiving a broadcast invitation to join the network, nodes that have not yet joined the network reply with their respective spreading codes to request to join the network. Nodes that have already joined the network but do not participate in communication use the spreading codes in the allocation table to scan and receive the broadcast invitation information, so that nodes in the network can receive the request to join the network.

4. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 3, characterized in that, The 64-bit information transmitted in the network broadcast frame is encoded in 1 / 4 and modulated by QPSK to form 128 symbols. A synchronization sequence is inserted to generate 257 modulation symbols. Each modulation symbol is spread symbol by symbol using a spreading sequence with a length of 3000.

5. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 1, characterized in that, The design for spreading low-speed data waveform input to the network includes frame structure design, as detailed below: The waveform frame structure uses one superframe every 1 second, and each superframe is divided into 128 subframes. Each subframe occupies a time length of 7.8125ms, and the guard time slot length is 500us, which is used for antenna beam switching time and air transmission delay.

6. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 5, characterized in that, The waveform frame structure is as follows: The 1st and 65th frames are forward broadcast frames. Broadcast frames can only send location coordinate information, with a maximum transmission of 64 bits. For broadcast frames, the antenna transmits and receives in all directions. In the frame structure design, broadcast frames are designed to occupy two time slots to transmit 64 bits of effective data. Frames 16 and 70 are reverse response frames. The maximum transmission length of a response frame is 384 bits. For response frames, the antenna transmits in a directional manner and receives in an omnidirectional manner. Compared with broadcast frames, the waveform has a higher channel rate. The response frame structure is specially designed to occupy a short time slot. The 19th and 73rd are acknowledgment frames, and the maximum length of an acknowledgment frame sent is 3200 bits. For the acknowledgment frame, the antenna transmits omnidirectionally and receives directionally. The channel rate of the acknowledgment frame and the response frame waveform are the same, occupying a long time slot.

7. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 6, characterized in that, The first time slot for network access is used for broadcasting. New nodes respond to network access requests in the 16th time slot, and nodes that send broadcasts send confirmation frames in the 19th time slot. These three frames are dedicated timing sequences for network access control. Other time slots in the frame structure are network protocol and service communication frames, which are dynamically allocated. The antenna transmits and receives in a directional manner, and different waveforms are selected for transmission according to the service. The highest rate is 64Mbps and the lowest rate is 8Mbps. The data transmission rate is adjusted by different spreading ratios, and the receiving end receives the data at an adaptive rate.

8. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 1, characterized in that, The network construction design includes: During the network construction phase, the start time of the network initialization phase of each node is different. Nodes establish links with other nodes by listening to omnidirectional channels or sending broadcast location messages. As long as a connection can be established with any node, it is considered that the network is necessary and possible to be established. After any node powers on, it first listens for several frames. If it receives a location message broadcast by another node in the first time slot, it replies with a network topology message in the specified time slot, and the physical layer uses spread spectrum to resolve conflicts. If no message is received after listening, it broadcasts a location message omnidirectionally at low speed in the first time slot and initiates a network access invitation. After receiving the network access invitation, other powered-on nodes choose to reply with an omnidirectional or directional network access request based on the distance, and the physical layer uses spread spectrum to resolve conflicts. If a broadcast location message is received in the first time slot, it replies after several time slots due to the limitations of signal processing delay and propagation delay.

9. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 8, characterized in that, Location messages contain no more than 72 bits of valid data, including the node's 8-bit ID and 64-bit coordinates. Once a neighboring node within a one-hop radius receives this location message, it knows the broadcast node's exact coordinates. Network topology messages contain not only the node's ID and coordinates but also the IDs and coordinates of its discovered one-hop neighbors. Nodes announce their known network topology through omnidirectional or directional transmissions. After receiving a network topology message, a broadcast node obtains the locations of other nodes, preparing for further neighbor discovery handshakes.

10. The rapid network establishment method for a phased array antenna communication system without location information as described in claim 9, characterized in that, After the network is established, network nodes operate in directional transmit / receive mode in other time slots. Nodes announce the network topology to each other and start timers. When the timer expires, if the network topology has not changed, the network enters the normal communication phase.

Images