A high throughput satellite communication system access method for a helicopter subscriber station

Abstract

The application relates to the field of satellite communication and discloses a high-throughput satellite communication system access method of a helicopter user station. The application designs a high-throughput satellite communication system of the helicopter user station, accesses the high-throughput system through a TDMA shared control channel, and realizes medium and high-speed service communication of the helicopter by combining an anti-rotor shielding technology based on low-code-rate deep interleaving, solves the rotor shielding problem of the helicopter platform, realizes fast and stable access of a helicopter cluster and other user multi-platform to the high-throughput satellite communication system at the same time, and realizes the functions of centralized network management of the helicopter cluster, dynamic management and control of resources, and on-demand access, handover and the like under the high-throughput satellite communication system.

Description

Technical Field

[0001] This invention relates to the field of satellite communications, and in particular to a high-throughput satellite communication system access method for helicopter user stations. Background Technology

[0002] With the large-scale application of high-throughput satellite communication systems, the number of users has grown rapidly, especially the application requirements for small-aperture antennas and special platform user stations. Among them, the special characteristics of helicopter airborne platforms, due to rotor shielding, affect the timing synchronization, channel transmission, and handover of high-throughput satellite communication systems. Helicopters mostly adopt the FDMA point-to-point communication system. How to achieve rapid and stable network access for helicopter fleets, centralized network and resource dynamic management and control, and seamless handover under high-throughput satellite communication systems has become a technical challenge. Summary of the Invention

[0003] In view of this, the present invention proposes a high-throughput satellite communication system access method for helicopter user stations. The present invention designs a high-throughput communication system for helicopter user stations, which accesses the high-throughput satellite communication system through a shared control channel, realizing centralized network management of helicopter fleets, dynamic resource control, and functions such as on-demand access and inter-area handover. Furthermore, it combines low-code-rate deep interleaving anti-rotor blocking technology to achieve medium- and high-speed service communication for helicopters.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A high-throughput satellite communication system access method for helicopter user stations, based on a gateway station, which includes a network controller and a channel terminal; specifically, it includes the following steps:

[0006] Step 1, Network Planning: The network controller performs network planning based on the requirements of the helicopter user stations, planning the entire network frame plan and helicopter user station information, and sends it through the channel terminal of the gateway station; the entire network frame plan includes the network parameters of the forward control carrier and the frequency, rate, reverse ranging time slot position and application information of the reverse control carrier; the entire network frame plan is carried by the reference carrier of the reference time slot in the forward control carrier, and the helicopter user station information is carried by the helicopter-dedicated carrier of the helicopter-dedicated time slot in the forward control carrier;

[0007] Step 2, Reference Acquisition: The helicopter user station enters the reference acquisition phase, receives the reference carrier in the beam according to the preset forward control carrier frequency and rate, and adjusts the station's receiving power and frequency offset until correct reception is achieved. Then, it parses out the full network frame plan and configures the current network parameters. At the same time, it obtains or compensates for the full network timing reference based on the received reference carrier.

[0008] Step 3, Timing Adjustment: The helicopter user station enters the ranging phase. Each helicopter user station and other user stations randomly compete for multiple ranging time slots in the back-end control carrier. Based on the frequency and rate of the back-end control carrier and the network-wide timing reference, the helicopter user station transmits ranging information in the ranging time slot via the back-end control carrier. Through interaction and auxiliary feedback with the gateway station, the helicopter user station adjusts its own transmission time, transmission level, and transmission frequency offset according to its geographical location. Then, it transmits the information to the channel terminal via the back-end control carrier after successful network access. The channel terminal parses the information and informs the network control.

[0009] Step 4, Service Communication: After successful network access, the helicopter user station enters the service communication phase. It reports the network status to the network controller through the channel terminal. The network controller dynamically generates the forward and return service carrier information of the helicopter user station according to the plan, including frequency and rate information, and configures the channel terminal to send the forward and return helicopter service carrier information in the helicopter-dedicated time slot of the forward control carrier. After receiving and correctly parsing the information, the helicopter user station performs anti-rotor service communication on the allocated forward and return helicopter service carriers.

[0010] Further steps include:

[0011] Step 5, Network Status Judgment: The helicopter user station receives service information on the forward service carrier, sends service information on the return service carrier, and periodically sends application information on the application time slot of the return control carrier;

[0012] Decommissioning status: After the helicopter user station is powered off or decommissioned, if the channel terminal cannot receive the application information sent by the helicopter user station within a fixed period, it is determined that the helicopter user station has decommissioned and the network control is notified. The network control then reclaims the allocated forward and return service carriers, and the helicopter user station enters the on-network monitoring status.

[0013] Handover Decision: When a helicopter user station flies across beams, it monitors its geographical location in real time to see if it has reached the beam edge. When it reaches the beam edge, it sends the beam edge arrival information to the channel terminal via a request message. The channel terminal parses the request and informs the network controller. The network controller calculates the beam number of the beam to be reached and, through the channel terminal, sends carrier information containing the upcoming beam via the full network frame plan. The helicopter user station obtains the return control carrier information under the upcoming beam from the carrier information based on the beam number and sends a request message. The channel terminal compares the signal-to-noise ratio of the received request message with the signal-to-noise ratio of the request message under the original beam. The system compares the signal-to-noise ratio (SNR) of the incoming beam's application information with that of the original beam's application information. When the SNR is greater than that of the original beam's application information, the system reports to the network control unit (NCU). The NCU determines whether to perform a new beam handover and sends new service carrier information, including frequency and polarization, through the helicopter-dedicated time slot of the channel terminal until a new service channel is established at the helicopter user station. Once the NCU determines to perform a new beam handover, it instructs the channel terminal to send a handover command. Upon receiving the handover command, the helicopter user station uses the service carrier parameters under the new beam for communication, thus enabling the helicopter user station to switch service channels during handover.

[0014] Furthermore, the multiple access mode for the forward control carrier and the back control carrier is TDMA. The forward control carrier includes a reference time slot and a helicopter-dedicated time slot, which is used to generate the timing reference for the entire network and to manage and control the network operation of all user stations, including helicopter user stations. Helicopter user stations share one or more carriers with other user stations in the network. The back control carrier includes a ranging time slot and a request time slot, which is used for uplink synchronization and request information transmission of all user stations in the network. Helicopter user stations share one carrier with other user stations in the network and randomly compete for time slots.

[0015] Both the forward and backward service carriers adopt FDMA multiple access and the helicopter's service communication is achieved based on low code rate deep interleaving anti-rotor blockage technology.

[0016] The helicopter-dedicated time slot in the forward control carrier repeatedly and randomly transmits helicopter user station information according to the helicopter time slot allocation strategy, and is designed with ultra-short data, with the shortest data not exceeding 40 bytes.

[0017] The advantages of this invention compared to the prior art are as follows:

[0018] 1. This invention addresses the issue of helicopter rotor shielding in special platforms accessing high-throughput satellite communication systems via TDMA shared control channels, enabling centralized network management, dynamic resource control, on-demand access, and inter-area handover for helicopter fleets.

[0019] 2. This invention supports helicopter group networking communication, solves the problem of rotor obstruction on helicopter platforms, and enables helicopter platforms and other user platforms to simultaneously and quickly and stably access high-throughput satellite communication systems.

[0020] 3. This invention can support multiple helicopter models, and only requires software parameter adaptation to enable access to high-throughput satellite communication systems for different helicopter platforms. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a high-throughput satellite communication system for helicopter user stations in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the helicopter user station frame structure design in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of system timing recovery of helicopter user stations based on reference carriers in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the helicopter user station link layer control information in an embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram illustrating the repeated random allocation of dedicated time slots for helicopter user stations in an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the network access process for a high-throughput satellite communication system for a helicopter user station in an embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of the handover process of the high-throughput satellite communication system for helicopter user stations in an embodiment of the present invention. Detailed Implementation

[0028] The invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] Figure 1 This is a schematic diagram of a high-throughput satellite communication system for helicopter user stations in an embodiment of the present invention.

[0030] A high-throughput satellite communication system access method for helicopter user stations comprises a high-throughput satellite communication network with a star topology, consisting of a gateway station and user stations. The gateway station serves as the central station of the star network, acting as the network management and service center, possessing functions such as network management and control, operation control, and integrated service switching and access. User stations (including fixed stations, vehicle-mounted stations, portable stations, and airborne stations) communicate with each other via a two-hop satellite connection for point-to-multipoint integrated service networking. Each station can access the high-throughput satellite communication system, supporting flexible and dynamic allocation of carrier and time slot resources on demand.

[0031] Due to the unique characteristics of helicopter user stations' rotor obstruction, access to high-throughput satellite communication systems is affected in terms of channel transmission, system timing, and handover. To meet the unified management and rapid, stable network access requirements of the high-throughput satellite communication system for helicopter user stations, forward / reverse control carriers and forward / reverse service carriers are designed separately. The forward / reverse control carriers use TDMA multiple access. The forward control carrier contains reference and control information, used to generate the network-wide timing reference and for network operation management and control of all user stations within the network, including helicopter user stations. Multiple helicopter user stations share one or more carriers with other user stations within the network. The reverse control carrier contains ranging time slots and request time slots, used for uplink synchronization and request information transmission of all user stations within the network. Multiple helicopter user stations share one carrier with other user stations within the network and randomly compete for time slots. Both forward and reverse service carriers adopt FDMA multiple access and are based on low-code-rate deep interleaving anti-rotor obstruction technology to achieve medium-to-high-speed service communication for helicopters.

[0032] Figure 2 This is a schematic diagram of the helicopter user station frame structure design in an embodiment of the present invention.

[0033] Helicopter user stations access high-throughput satellite communication systems by sharing reference and ranging time slots with other users on the forward and return control carriers. The configuration is flexible and can be tailored to different helicopter models. Within the helicopter-dedicated time slots on the forward control carrier, helicopter user station information is repeatedly and randomly transmitted according to a dedicated time slot allocation strategy, with ultra-short data transmission designed, the shortest data size not exceeding 40 bytes. Both the forward and return service carriers employ rotor-resistant designs to ensure the continuity and accuracy of service data.

[0034] The forward control carrier and the backward control carrier are designed based on the frame structure and network communication process of the high-throughput TDMA system. The helicopter user station extracts the timing reference of the entire network by receiving the reference carrier of the master station. However, due to the rotor blockage of the helicopter, there may be situations where the reference carrier is not received continuously or is mis-acquired. The frame structure is designed to be adapted to the helicopter by combining the relevant parameters of the helicopter rotor. This can ensure that there is no situation where the reference is not received continuously or for more than three consecutive frames. For situations where the reference is not received for two consecutive frames or for one frame, the helicopter user station generates the required timing reference based on the timing compensation of the entire network.

[0035] The high-throughput network-wide timing reference is the timing reference equipment of the gateway station. The helicopter user station extracts the network-wide timing reference based on the reference carrier sent by the channel terminal of the gateway station.

[0036] Assuming the reference carrier rate is 1024 ksps, the modulation scheme is QPSK, and the coding scheme is LDPC, with a reference information length of 1000 bytes, then the channel occupancy time is... The transmission period is 100ms. The helicopter user station is designed to generate a timing reference based on the frame length counted by the local clock.

[0037] Figure 3 This is a schematic diagram of system timing recovery of helicopter user stations based on reference carriers in an embodiment of the present invention.

[0038] Taking a MiG helicopter as an example, its blocking period is 62.5ms. Assuming a 30% blocking rate and a fixed frame header for the reference burst, the probability of the reference not being received for 100 consecutive frames is... for:

[0039] (1)

[0040] The probability of not receiving a signal for 100 consecutive frames It's practically impossible for this to happen; the probability of missing two consecutive frames can be obtained using the above formula. There are approximately 8 instances within 100 frames where two consecutive frames fail to receive a reference. Since the TDMA system allows a timing error of 10µs, and the helicopter's onboard terminal clock accuracy is 0.1ppm, the error caused by the clock is... Then, under the condition of an error of 10µs, after A frame rate of 100 frames is achievable, but since the reference carrier needs to be processed for each frame and there is no accumulation of errors across multiple frames, errors caused by clock stability can be disregarded. Only compensation for the timing reference is needed in the event of frame loss or false acquisition at the helicopter user station, and the reference acquisition window margin is designed to be [missing information]. .

[0041] Figure 4 This is a schematic diagram of helicopter user station helicopter dedicated time slot link layer control information in an embodiment of the present invention.

[0042] The helicopter-dedicated time slot return control information includes station information and application information, while the helicopter-dedicated time slot forward control information includes station information, assistance information, forward service carrier parameters, and return service carrier parameters. Helicopters can change parameters such as the transmit and receive frequencies, modulation and coding schemes, and polarization of the forward and return service carriers according to gateway station control commands, achieving cross-beam cross-area communication and meeting the requirements of multi-beam communication for helicopters. To minimize the impact of rotor obstruction and reduce the number of bytes in the helicopter-dedicated time slot, this invention designs the helicopter-dedicated time slot for the forward control carrier to carry only 20 bytes of data information, and the helicopter-dedicated time slot for the return control carrier to carry only 10 bytes of data information. It also supports helicopter fleets; for example, when ensuring 10 helicopters are simultaneously connected to the network, the forward control information length is 220 bytes, and the helicopter control data duration is... The probability of not receiving helicopter-specific time slot data for N consecutive frames is:

[0043] (2)

[0044] The probability of failing to receive two consecutive frames is: In approximately 1000 frames, only 7 frames continuously fail to receive control information. For a helicopter swarm, this low probability is sufficient to meet the system requirements.

[0045] Figure 5 This is a schematic diagram illustrating the repeated random allocation of dedicated time slots for helicopter user stations in an embodiment of the present invention.

[0046] Depending on the helicopter model, the rotor blockage model software can be configured to add a dedicated helicopter time slot design. Based on the network scale and frame utilization requirements, the dedicated helicopter time slots can be allocated randomly or in a fixed manner, and can be randomly and repeatedly transmitted multiple times according to the rotor blockage model, thus adapting to various helicopter models.

[0047] The above design enables helicopter clusters to quickly and stably access high-throughput satellite communication systems.

[0048] Figure 6 This is a schematic diagram of a high-throughput satellite communication system access method for a helicopter user station according to an embodiment of the present invention. Specifically, it includes the following steps:

[0049] Step 1, Network Planning: The network controller performs network planning based on the requirements of the helicopter user stations, planning the entire network frame plan and helicopter user station information, and sends it through the channel terminal of the gateway station; the entire network frame plan includes the network parameters of the forward control carrier and the frequency, rate, reverse ranging time slot position and application information of the reverse control carrier; the entire network frame plan is carried by the reference carrier of the reference time slot in the forward control carrier, and the helicopter user station information is carried by the helicopter-dedicated carrier of the helicopter-dedicated time slot in the forward control carrier;

[0050] Step 2, Reference Acquisition: The helicopter user station enters the reference acquisition phase, receives the reference carrier in the beam according to the preset forward control carrier frequency and rate, and adjusts the station's receiving power and frequency offset until correct reception is achieved. Then, it parses out the full network frame plan and configures the current network parameters. At the same time, it obtains or compensates for the full network timing reference based on the received reference carrier.

[0051] Step 3, Timing Adjustment: The helicopter user station enters the ranging phase. Each helicopter user station and other user stations randomly compete for multiple ranging time slots in the back-end control carrier. Based on the frequency and rate of the back-end control carrier and the network-wide timing reference, the helicopter user station transmits ranging information in the ranging time slot via the back-end control carrier. Through interaction and auxiliary feedback with the gateway station, the helicopter user station adjusts its own transmission time, transmission level, and transmission frequency offset according to its geographical location. Then, it transmits the information to the channel terminal via the back-end control carrier after successful network access. The channel terminal parses the information and informs the network control.

[0052] Step 4, Service Communication: After successful network access, the helicopter user station enters the service communication phase. It reports the network status to the network controller through the channel terminal. The network controller dynamically generates the forward and return service carrier information of the helicopter user station according to the plan, including frequency and rate information, and configures the channel terminal to send the forward and return helicopter service carrier information in the helicopter-dedicated time slot of the forward control carrier. After receiving and correctly parsing the information, the helicopter user station performs anti-rotor service communication on the allocated forward and return helicopter service carriers.

[0053] Step 5, Network Status Judgment: The helicopter user station receives service information on the forward service carrier, sends service information on the return service carrier, and periodically sends application information on the application time slot of the return control carrier;

[0054] Decommissioning status: After the helicopter user station is powered off or decommissioned, if the channel terminal cannot receive the application information sent by the helicopter user station within a fixed period, it is determined that the helicopter user station has decommissioned and the network control is notified. The network control then reclaims the allocated forward and return service carriers, and the helicopter user station enters the on-network monitoring status.

[0055] Figure 7This is a schematic diagram of the handover process of a high-throughput satellite communication system for a helicopter user station in an embodiment of the present invention. Handover decision: When the helicopter user station flies across beams, it monitors in real time whether it has reached the beam edge based on its geographical location. When it reaches the beam edge, it sends the beam edge arrival information to the channel terminal via a request message. The channel terminal parses the request and informs the network controller. The network controller calculates the beam number of the beam to be reached and, through the channel terminal, sends carrier information containing the upcoming beam via a full-frame plan. The helicopter user station obtains the return control carrier information under the upcoming beam from the carrier information based on the beam number and sends a request message. The channel terminal compares the signal-to-noise ratio of the received request message with the signal-to-noise ratio of the request message under the original beam. The system compares the signal-to-noise ratio (SNR) of the incoming beam's application information with that of the original beam's application information. When the SNR is greater than that of the original beam's application information, the system reports to the network control unit (NCU). The NCU determines whether to perform a new beam handover and sends new service carrier information, including frequency and polarization, through the helicopter-dedicated time slot of the channel terminal until a new service channel is established at the helicopter user station. Once the NCU determines to perform a new beam handover, it instructs the channel terminal to send a handover command. Upon receiving the handover command, the helicopter user station uses the service carrier parameters under the new beam for communication, thus enabling the helicopter user station to switch service channels during handover.

[0056] In summary, this invention enables centralized network management, dynamic resource control, on-demand access, and inter-area handover for helicopter fleets by sharing the control carrier via TDMA to access high-throughput satellite communication systems. It supports helicopter fleet network communication, solves the rotor blockage problem of helicopter platforms, and enables helicopter platforms and other user platforms to simultaneously and quickly and stably access high-throughput satellite communication systems.

Claims

1. A high-throughput satellite communication system access method for a helicopter user station, implemented based on a gateway station, the gateway station comprising a network controller and a channel terminal; characterized in that, Specifically, the following steps are included: Step 1, Network Planning: The network controller performs network planning based on the requirements of helicopter user stations, planning the entire network frame plan and helicopter user station information, and sends it through the channel terminal of the gateway station; the entire network frame plan includes the network parameters of the forward control carrier and the frequency, rate, return ranging time slot position and application information of the return control carrier; the entire network frame plan is carried by the reference carrier of the reference time slot in the forward control carrier, and the helicopter user station information is carried by the helicopter-dedicated carrier of the helicopter-dedicated time slot in the forward control carrier; Step 2, Reference Acquisition: The helicopter user station enters the reference acquisition phase, receives the reference carrier in the beam according to the preset forward control carrier frequency and rate, and adjusts the station's receiving power and frequency offset until correct reception is achieved. Then, it parses out the full network frame plan and configures the current network parameters. At the same time, it obtains or compensates for the full network timing reference based on the received reference carrier. Step 3, Timing Adjustment: The helicopter user station enters the ranging phase. Each helicopter user station and other user stations randomly compete for multiple ranging time slots in the return control carrier. Based on the frequency and rate of the return control carrier and the network-wide timing reference, the helicopter user station transmits ranging information in the ranging time slots via the return control carrier. Through interaction and auxiliary feedback with the gateway station, the helicopter user station adjusts its transmission time, transmission level, and transmission frequency offset according to its own geographical location. Then, it sends a network access success message to the channel terminal via the return control carrier. The channel terminal parses the message and informs the network control. Step 4, Service Communication: After successful network access, the helicopter user station enters the service communication phase. It reports the network status to the network controller through the channel terminal. The network controller dynamically generates the forward and return service carrier information of the helicopter user station according to the plan, including frequency and rate information, and configures the channel terminal to send the forward and return helicopter service carrier information in the helicopter-dedicated time slot of the forward control carrier. After receiving and correctly parsing the information, the helicopter user station performs anti-rotor service communication on the allocated forward and return helicopter service carriers. The forward control carrier and the backward control carrier use TDMA as their multiple access method. The forward control carrier includes a reference time slot and a helicopter-dedicated time slot, which are used to generate the timing reference for the entire network and to manage and control the network operation of all user stations, including helicopter user stations. Helicopter user stations share one or more carriers with other user stations in the network. The backward control carrier includes a ranging time slot and a request time slot, which are used for uplink synchronization and request information transmission for all user stations in the network. Helicopter user stations share one carrier with other user stations in the network and randomly compete for time slots. Both the forward and backward service carriers adopt FDMA multiple access and the helicopter's service communication is achieved based on low code rate deep interleaving anti-rotor blockage technology. The helicopter-dedicated time slot in the forward control carrier repeatedly and randomly transmits helicopter user station information according to the helicopter time slot allocation strategy, and is designed with ultra-short data, with the shortest data not exceeding 40 bytes.

2. The high-throughput satellite communication system access method for a helicopter user station according to claim 1, characterized in that, It also includes the following steps: Step 5, Network Status Judgment: The helicopter user station receives service information on the forward service carrier, sends service information on the return service carrier, and periodically sends application information on the application time slot of the return control carrier; Decommissioning status: After the helicopter user station is powered off or decommissioned, if the channel terminal cannot receive the application information sent by the helicopter user station within a fixed period, it is determined that the helicopter user station has decommissioned and the network control is notified. The network control then reclaims the allocated forward and return service carriers, and the helicopter user station enters the on-network monitoring status. Handover Decision: When a helicopter user station flies across beams, it monitors its geographical location in real time to see if it has reached the beam edge. When it reaches the beam edge, it sends the beam edge arrival information to the channel terminal via a request message. The channel terminal parses the request and informs the network controller. The network controller calculates the beam number of the beam to be reached and, through the channel terminal, sends carrier information containing the upcoming beam via the full network frame plan. The helicopter user station obtains the return control carrier information under the upcoming beam from the carrier information based on the beam number and sends a request message. The channel terminal compares the signal-to-noise ratio of the received request message with the signal-to-noise ratio of the request message under the original beam. The system compares the signal-to-noise ratio (SNR) of the incoming beam's application information with that of the original beam's application information. When the SNR is greater than that of the original beam's application information, the system reports to the network control unit (NCU). The NCU determines whether to perform a new beam handover and sends new service carrier information, including frequency and polarization, through the helicopter-dedicated time slot of the channel terminal until a new service channel is established at the helicopter user station. Once the NCU determines to perform a new beam handover, it instructs the channel terminal to send a handover command. Upon receiving the handover command, the helicopter user station uses the service carrier parameters under the new beam for communication, thus enabling the helicopter user station to switch service channels during handover.

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