A high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites

Abstract

The present invention addresses the problem that satellite communication systems are susceptible to interference attacks due to open channels and relatively fixed satellite orbit information, and proposes a highly resilient anti-interference satellite communication method based on dual-beam user terminals and multiple satellites, which belongs to the field of satellite communications. During the operation of the main beam of the user terminal, the backup beam polls and detects the available communication resources of multiple satellites to obtain the channel status. When the main beam is interrupted by an interference attack, the backup beam is switched to the main beam in a very short time to restore and maintain smooth communication. The main beam is then switched to the backup beam simultaneously, and polling continues between the available communication resources, thereby forming a user satellite communication network with higher resilience and stronger anti-interference capabilities. The method of the present invention has a short anti-interference and communication maintenance time for the satellite communication system after interference, and is suitable for the design and development of key user satellite communication systems and user terminals with resilience and anti-interference communication requirements as the main requirements.

Description

Technical Field

[0001] The invention relates to a high-toughness anti-interference satellite communication method based on a dual-beam user terminal and multiple satellites, and belongs to the field of satellite communications. Background Art

[0002] Satellite communication systems, with their wide coverage and flexible networking capabilities independent of ground infrastructure, have become a vital, or even the sole, means of ensuring communications for applications spanning vast territories and those operating in remote areas and offshore. However, because satellite communication channels are open and satellite orbital information is relatively fixed, these systems are vulnerable to interference attacks from wireless channels. For example, evaluations of satellite communication countermeasure systems (CCS) have shown that they can disable transparent relay satellites or significantly degrade their processing capabilities using high-powered blocking jamming signals. The practical application requirements of strong electromagnetic countermeasures dictate that satellite communication systems used for critical missions or for key users must possess high resilience and strong anti-interference capabilities.

[0003] Currently, my country's in-orbit communications satellites are primarily geosynchronous transparent relay satellites, supplemented by a small number of geosynchronous processing and relay satellites. Satellite communications support plans for key application areas primarily utilize multiple satellites and beams to create multiple coverage areas. When encountering malicious interference, countermeasures are taken, including replacing transponders and satellites. However, because most satellite communication user terminals operate on a single beam, mitigation measures after interference present challenges, such as difficulty coordinating backup communication resources and lengthy satellite switching operations. Consequently, communication interruption and restoration take a long time, resulting in insufficient communication resilience and anti-interference capabilities. Summary of the Invention

[0004] The present invention aims to solve the problem of long communication link recovery time for satellite communication user stations after being attacked by interference. It proposes a highly resilient and anti-interference satellite communication method based on dual-beam user terminals and multiple satellites. By increasing the number of available satellites in the system and designing a multi-satellite communication joint application method with dual-beam user terminals as the core, the communication link recovery time after interference is reduced from hours to seconds, providing key users with a resilient and anti-interference satellite communication guarantee method.

[0005] The technical solution of the present invention is achieved as follows:

[0006] A high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites, implemented based on user communication station-type dual-beam user terminals, multiple communication satellites, and central stations / regional stations;

[0007] The dual-beam user terminal of the user communication station type is configured with two antenna radio frequency units that simultaneously transmit and receive beams in different directions, two channel processing units that simultaneously process beams, a service access and processing unit, and a main control unit. The antenna radio frequency unit and channel processing unit that process one beam are called a channel. The dual-beam user terminal initially selects one channel as the current main channel and the other channel as a backup channel. The multiple communication satellites are all geosynchronous orbit communication satellites. Initially, one communication satellite is selected as the main satellite, and the rest are backup satellites. The central station / regional station is configured with multiple sets of antenna radio frequency units and channel processing units, and one set of service access and processing units.

[0008] The processing process on the dual-beam user terminal side is as follows:

[0009] Step 1: The dual-beam user terminal uses the current primary channel to establish a primary communication link with the central station / regional station via the primary satellite, and conducts two-way communication with the central station / regional station via the internal service access and processing unit and the current primary channel. During the communication process, the current primary channel reports the link status to the main control unit. At the same time, the dual-beam user terminal uses the backup channel to establish a backup communication link with the central station / regional station via the backup satellite. The backup channel periodically polls multiple backup satellites to obtain channel status and reports the obtained channel status to the main control unit. The link status includes carrier lock indication, decoding lock indication, bit error rate indication, and received signal-to-noise ratio indication.

[0010] Step 2: The main control unit makes a judgment based on the link status reported by the current primary channel. If it is determined that the primary satellite is under interference attack from a high-power jammer, resulting in communication link interruption or degradation exceeding a predetermined threshold, the main control unit controls the service access and processing unit to switch user service data from the current primary channel to the backup channel. At the same time, a backup satellite is selected as the primary satellite based on the channel status reported by the backup channel, and the backup channel is used as the current primary channel.

[0011] The processing process on the central station / regional station side is as follows:

[0012] Step 3: Multiple antenna radio frequency units and channel processing units in the central station / regional station simultaneously receive wireless signals from multiple communication satellites. The service access and processing unit in the central station / regional station detects user service data, selects the primary channel, and sends the service data to the dual-beam user terminal side via the primary satellite.

[0013] Step 4: When the primary satellite is attacked by interference from a high-power jammer, causing the communication link to be interrupted or degraded beyond a predetermined threshold, the remote dual-beam user terminal switches to the primary channel. The central station / regional station receives and detects the user service data transmission channel switch and synchronously switches the user service data transmission signal to the channel that matches the received signal.

[0014] Step 5: Continue to maintain the communication status until the communication channel is switched in step 4 when interference occurs again. When the user mission is completed, the satellite communication link is dismantled and the communication is terminated.

[0015] Furthermore, in step 2, the link status reported by the current active channel is judged. The specific process is as follows:

[0016] When the carrier lock indication and decoding lock indication of the original normal communication link are both lost, it means that the communication satellite has been attacked by interference, resulting in communication interruption and link unavailability; when the carrier lock indication and decoding lock indication are both locked, the bit error rate indication increases beyond the preset threshold and the received signal-to-noise ratio decreases beyond the preset threshold, it means that the communication satellite has been attacked by interference, resulting in degradation of the communication link capability.

[0017] Furthermore, the selection of multiple communication satellites meets the following requirements:

[0018] ① The satellite beam can cover the dual-beam user terminal of the user communication station type and meet the requirement that the elevation angle of the dual-beam user terminal antenna beam to the satellite is not less than 15°; ② The satellite beam can cover the communication target of the dual-beam user terminal or can use another communication satellite to cover the communication target via the intersatellite link; ③ The satellite frequency band is consistent with the dual-beam user terminal frequency band and has transponder bandwidth and time slot resources that can meet user communication needs; ④ One of the communication satellites is the primary satellite, and the remaining communication satellites are backup satellites. Both the primary satellite and the backup satellite have reserved communication resources for the dual-beam user terminal.

[0019] Furthermore, in step 1, the backup channel periodically polls and detects between multiple backup satellites to obtain channel status, including the following steps:

[0020] Step 1: The dual-beam user terminal uses a backup channel to send a sounding signal via a backup satellite;

[0021] Step 2: The central station / regional station receives the detection signal from the remote dual-beam user terminal and estimates the received signal-to-noise ratio and received bit error rate parameters;

[0022] Step 3: The central station / regional station uses the corresponding backup satellite to send a probe response signal, and carries the locally estimated receive signal-to-noise ratio and receive bit error rate parameters along with the probe response signal;

[0023] Step 4: The remote dual-beam user terminal uses the backup channel to receive the probe response signal from the central station / regional station, estimates the received signal-to-noise ratio and received bit error rate parameters, and simultaneously analyzes the received signal-to-noise ratio and received bit error rate parameters sent by the central station / regional station.

[0024] Step 5: The backup channel of the remote dual-beam user terminal records the received signal-to-noise ratio and received bit error rate parameters of both ends when using the backup satellite to detect and handshake with the central station / regional station, and reports the parameters to the main control unit;

[0025] Step 6: After completing a detection handshake, the dual-beam user terminal uses the backup channel to adjust its alignment to another backup satellite and repeats steps 1 to 5 until all backup satellites are polled and detected.

[0026] Furthermore, in step 2, the main control unit divides multiple channels into three states: standby, emergency and emergency according to the channel quality. When the receiving bit error rate meets the mission requirements, the channel states are sorted according to the receiving signal-to-noise ratio; the communication satellite in the standby state is preferentially selected as the backup satellite, and when the communication satellite in the standby state is interrupted by interference, the communication satellite in the emergency state is selected as the backup satellite; when the communication satellite in the emergency state is interrupted by interference, the communication satellite in the emergency state is selected as the backup satellite.

[0027] The advantages of the present invention are:

[0028] 1. Highly resilient communication system. The method proposed in this invention provides multiple communication satellite resources for key users. Given the basic process of interference, which requires prior reconnaissance, simultaneous reconnaissance and coordinated interference of multiple satellites is difficult, and there are currently no public reports on this aspect. Therefore, this invention can provide users with highly resilient communication assurance capabilities.

[0029] 2. Strong anti-interference capabilities. The method proposed in this invention enables rapid switching to a backup link when an interfered link is interrupted or degraded to a predetermined threshold. Building on conventional signal-layer anti-interference measures (such as frequency hopping or spread spectrum and error correction coding), it adds a multi-satellite, multi-link approach to counter interference sources. This approach switches to interference targets much faster than a single interfering station, evading interference attacks. This provides users with anti-interference communication assurance, addressing the problem of satellite communication network paralysis caused by the susceptibility of single conventional transparent relay communication satellites to blocking interference attacks.

[0030] 3. Short communication recovery time after interruption. This invention proposes a method for ensuring communication using multiple satellites based on dual-beam user terminals. The primary and backup links operate simultaneously, resulting in signal switching times in nanoseconds and service recovery times in milliseconds. This compares to the minute-scale satellite switching required by traditional single-beam user terminals (if resource coordination is added, the switching time can be in the order of hours). This shortens the time it takes to restore communication after an interruption, ensuring high real-time user communication.

[0031] 4. Low engineering implementation difficulty. The dual-beam user terminal proposed in this invention is based on the mature and common single-beam user terminal. It is relatively easy to expand and improve by adding channel transmission, antenna RF processing channels, and other methods. The R&D cost is relatively low and the engineering implementation technical difficulty is relatively low. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of an application scenario of the present invention.

[0033] Figure 2 This is a functional composition diagram of the dual-beam user terminal of the present invention.

[0034] Figure 3 This is a flow chart of the channel quality timing polling detection of the present invention. DETAILED DESCRIPTION

[0035] The following is combined with Figures 1 to 3 It should be noted that in the following description, when the detailed description of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0036] Figure 1 The following is a schematic diagram of the application scenario of the present invention, in which a number of communication satellites are allocated to a user communication station type planning using a dual-beam user terminal for mission support. Figure 1 The primary link of China Communications Satellite 2 communicates with the central / regional stations, while the backup beam of the dual-beam user terminal polls the communication link status between backup satellites. If the primary link is attacked by a high-power jammer, causing interruption or degradation exceeding a predetermined threshold, user service data is automatically switched to the backup link for transmission, switching the original primary beam to the backup beam and continuing to poll the link status between the assigned multiple satellites. Because both beams are simultaneously active, the switching is very fast (service recovery time is in the order of milliseconds). Because this communication method deploys multiple communication satellites and utilizes a newly designed dual-beam user terminal, the system's communication assurance capabilities are highly resilient and highly resistant to interference.

[0037] Figure 2 The figure shows the functional composition of the dual-beam user terminal of the present invention. Compared with conventional single-beam user terminals, in addition to the service access and processing unit and the main control unit, the design uses two sets of channel processing and antenna radio frequency units. The antenna radio frequency unit and channel processing unit that process one beam are called a channel. Therefore, the dual-beam user terminal can simultaneously communicate with two communication satellites in different orbits. Figure 2 The two channels in the switch form a master and backup relationship, which is a real-time online hot backup. The outstanding advantage is the fast switching response speed.

[0038] The present invention describes a high-resilience, anti-interference satellite communication method based on a dual-beam user terminal and multiple satellites. It is assumed that three communication satellites that can simultaneously cover the user's location are planned and allocated for communication guarantee. The three communication satellites are respectively recorded as Satellite 1, Satellite 2 and Satellite 3. The elevation angle of the user station communication beam to the three satellites is not less than 15°. The three satellite beams can cover the user's communication target, such as the central station / regional station. The three satellites are allocated communication resources such as frequency, time slot and power that can be used by the user. However, only one of the communication satellites is used as the main satellite at the same time, and the remaining communication satellites are used as backup satellites. The communication mission requires a channel bit error rate better than 1E-7. The user communication station is configured with a dual-beam user terminal that can simultaneously transmit and receive satellite beams in two different directions. The central station / regional station is configured with multiple sets of antenna radio frequency units and channel processing units and a set of service access and processing units that can simultaneously transmit and receive three communication satellites. The specific implementation methods are given as follows:

[0039] The processing process on the dual-beam user terminal side is as follows:

[0040] Step 1: The dual-beam user terminal uses the current primary channel as channel A and satellite 2 as the primary satellite to establish a primary communication link with the central station / regional station through the primary satellite. The terminal then conducts two-way communication with the central station / regional station through the internal service access and processing unit and the current primary channel. During the communication process, the current primary channel reports the link status to the main control unit. Simultaneously, satellites 1 and 3 are used as backup satellites. The dual-beam user terminal uses the backup channel to establish a backup communication link with the central station / regional station through the backup satellites. The backup channel periodically polls between satellites 1 and 3 to obtain the channel status, and reports the acquired channel status to the main control unit. The link status includes a carrier lock indication, a decoding lock indication, a bit error rate indication, and a received signal-to-noise ratio indication.

[0041] Step 2: The main control unit makes a judgment based on the link status reported by the current primary channel. If it is determined that satellite 2 is under interference attack from a high-power jammer, causing the communication link to be interrupted or degraded beyond a predetermined threshold, it controls the service access and processing unit to switch user service data from the current primary channel to the backup channel. At the same time, based on the channel status reported by the backup channel, satellite 1 is selected as the primary satellite and the backup channel is used as the current primary channel.

[0042] The processing process on the central station / regional station side is as follows:

[0043] Step 3: The three antenna radio frequency units and channel processing units in the central station / regional station simultaneously receive wireless signals from satellites 1, 2, and 3. The service access and processing unit in the central station / regional station detects user service data, selects the primary channel, and sends the service data to the dual-beam user terminal via the primary satellite 2.

[0044] Step 4: When the primary satellite 2 is attacked by interference from a high-power jammer, causing the communication link to be interrupted or degraded beyond a predetermined threshold, the remote dual-beam user terminal switches to the primary channel. The central station / regional station receives and detects the user service data transmission channel switching and synchronously switches the user service data transmission signal to the channel that matches the received signal.

[0045] Step 5: Continue to maintain the communication status until the communication channel is switched in step 4 when the user is disturbed again. When the user mission is completed, the satellite communication link is dismantled and the communication is terminated.

[0046] In step 2, the link status reported by the current active channel is used for judgment. The specific process is as follows:

[0047] When the carrier lock indication and decoding lock indication of the original normal communication link are both lost, it means that the communication satellite has been attacked by interference, resulting in communication interruption and link unavailability; when the carrier lock indication and decoding lock indication are both locked, the bit error rate indication increases beyond the preset threshold and the received signal-to-noise ratio decreases beyond the preset threshold, it means that the communication satellite has been attacked by interference, resulting in degradation of the communication link capability.

[0048] like Figure 3 As shown, the specific implementation method of the central station / regional station cooperating with the remote dual-beam user terminal to complete the channel quality timing polling detection to obtain the channel status is given as follows:

[0049] Step 1: The dual-beam user terminal uses channel B to send a sounding signal to backup satellite 1;

[0050] Step 2: The central station / regional station receives the detection signal from the backup satellite 1 and estimates the received signal-to-noise ratio and received bit error rate parameters. Assume that the received signal-to-noise ratio is 10 dB and the received bit error rate parameter is 1.5E-8.

[0051] Step 3: The central station / regional station sends a probe response signal via satellite 1, along with the locally estimated receive signal-to-noise ratio (10 dB) and receive bit error rate (BER) parameters (1.5E-8).

[0052] Step 4: The remote dual-beam user terminal receives the probe response signal from the central station / regional station and estimates the received signal-to-noise ratio (SNR) and received bit error rate (BER) parameters based on the received SNR. Assuming the SNR is 8dB and the BER parameter is 3.3E-8, ​​the remote dual-beam user terminal simultaneously analyzes the SNR (10dB) and BER parameters (1.5E-8) sent by the central station / regional station and reports the SNR and BER parameters of both ends to the main control unit.

[0053] Step 5: After completing a detection handshake, the dual-beam user terminal adjusts the backup beam to align with satellite 3. The detection process is the same as steps 1 to 4. It is assumed that when using satellite 3 for detection polling, the central station / regional station receives a signal-to-noise ratio of 7 dB and a bit error rate of 6.5E-8, and the dual-beam user terminal receives a signal-to-noise ratio of 5 dB and a bit error rate of 8.2E-8.

[0054] The master control unit classifies multiple channels into standby, emergency, and emergency states based on current channel quality (link status reported by the backup channel). In this embodiment, after completing a quality poll of all planned backup communication satellite channels, if the receive bit error rates of both satellites 1 and 3 meet mission requirements (better than 1E-7) and the receive signal-to-noise ratio of the satellite 1 link is higher than that of the satellite 3 link, the satellite 1 link is marked as "standby" and the satellite 3 link as "emergency." If the active satellite 2 link is disrupted, the "standby" link of satellite 1 is prioritized. If the "standby" link of satellite 1 is disrupted, the "emergency" link of satellite 3 is switched to.

[0055] The examples visually demonstrate the process of communication from normal to interrupted and then back to restored communication using a dual-beam user terminal proposed by the present invention for multi-satellite communication. This demonstrates the method's high system resilience and strong anti-interference capabilities. In actual operation, the system can achieve even higher resilience and anti-interference capabilities by investing more satellite resources. For simultaneous use by multiple user stations, backup links in addition to the primary link can serve as a resource pool for simultaneous anti-interference backup.

[0056] The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent replacement or modification made by a person skilled in the art based on the technical solution and inventive concept of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites, characterized in that: Implementation based on dual-beam user terminals, multiple communication satellites, and central / regional stations for user communication stations; The dual-beam user terminal of the user communication station type is configured with two antenna radio frequency units that simultaneously transmit and receive beams in different directions, two channel processing units that simultaneously process beams, a service access and processing unit, and a main control unit. The antenna radio frequency unit and channel processing unit that process one beam are called a channel. The dual-beam user terminal initially selects one channel as the current main channel and the other channel as a backup channel. The multiple communication satellites are all geosynchronous orbit communication satellites. Initially, one communication satellite is selected as the main satellite, and the rest are backup satellites. The central station / regional station is configured with multiple sets of antenna radio frequency units and channel processing units, and one set of service access and processing units. The processing process on the dual-beam user terminal side is as follows: Step 1: The dual-beam user terminal uses the current primary channel to establish a primary communication link with the central station / regional station via the primary satellite, and conducts two-way communication with the central station / regional station via the internal service access and processing unit and the current primary channel. During the communication process, the current primary channel reports the link status to the main control unit. At the same time, the dual-beam user terminal uses the backup channel to establish a backup communication link with the central station / regional station via the backup satellite. The backup channel periodically polls multiple backup satellites to obtain channel status and reports the obtained channel status to the main control unit. The link status includes carrier lock indication, decoding lock indication, bit error rate indication, and received signal-to-noise ratio indication. Step 2: The main control unit makes a judgment based on the link status reported by the current primary channel. If it is determined that the primary satellite is under interference attack from a high-power jammer, resulting in communication link interruption or degradation exceeding a predetermined threshold, the main control unit controls the service access and processing unit to switch user service data from the current primary channel to the backup channel. At the same time, a backup satellite is selected as the primary satellite based on the channel status reported by the backup channel, and the backup channel is used as the current primary channel. The processing process on the central station / regional station side is as follows: Step 3: Multiple antenna radio frequency units and channel processing units in the central station / regional station simultaneously receive wireless signals from multiple communication satellites. The service access and processing unit in the central station / regional station detects user service data, selects the primary channel, and sends the service data to the dual-beam user terminal side via the primary satellite. Step 4: When the primary satellite is attacked by interference from a high-power jammer, causing the communication link to be interrupted or degraded beyond a predetermined threshold, the remote dual-beam user terminal switches to the primary channel. The central station / regional station receives and detects the user service data transmission channel switch and synchronously switches the user service data transmission signal to the channel that matches the received signal. Step 5: Continue to maintain the communication status until the communication channel is switched in step 4 when interference occurs again. When the user mission is completed, the satellite communication link is dismantled and the communication is terminated.

2. The high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites according to claim 1, characterized in that: In step 2, the link status reported by the current active channel is used for judgment. The specific process is as follows: When the carrier lock indication and decoding lock indication of the original normal communication link are both lost, it means that the communication satellite has been attacked by interference, resulting in communication interruption and link unavailability; when the carrier lock indication and decoding lock indication are both locked, the bit error rate indication increases beyond the preset threshold and the received signal-to-noise ratio decreases beyond the preset threshold, it means that the communication satellite has been attacked by interference, resulting in degradation of the communication link capability.

3. The high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites according to claim 1, characterized in that: The selection of multiple communication satellites must meet the following requirements: ① The satellite beam can cover the dual-beam user terminal of the user communication station type and meet the requirement that the elevation angle of the dual-beam user terminal antenna beam to the satellite is not less than 15°; ② The satellite beam can cover the communication target of the dual-beam user terminal or can use another communication satellite to cover the communication target via the intersatellite link; ③ The satellite frequency band is consistent with the dual-beam user terminal frequency band and has transponder bandwidth and time slot resources that can meet user communication needs; ④ One of the communication satellites is the primary satellite, and the remaining communication satellites are backup satellites. Both the primary satellite and the backup satellite have reserved communication resources for the dual-beam user terminal.

4. The high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites according to claim 1, characterized in that: In step 1, the backup channel periodically polls and detects between multiple backup satellites to obtain channel status, including the following steps: Step 1: The dual-beam user terminal uses a backup channel to send a sounding signal via a backup satellite; Step 2: The central station / regional station receives the detection signal from the remote dual-beam user terminal and estimates the received signal-to-noise ratio and received bit error rate parameters; Step 3: The central station / regional station uses the corresponding backup satellite to send a probe response signal, and carries the locally estimated receive signal-to-noise ratio and receive bit error rate parameters along with the probe response signal; Step 4: The remote dual-beam user terminal uses the backup channel to receive the probe response signal from the central station / regional station, estimates the received signal-to-noise ratio and received bit error rate parameters, and simultaneously analyzes the received signal-to-noise ratio and received bit error rate parameters sent by the central station / regional station. Step 5: The backup channel of the remote dual-beam user terminal records the received signal-to-noise ratio and received bit error rate parameters of both ends when using the backup satellite to detect and handshake with the central station / regional station, and reports the parameters to the main control unit; Step 6: After completing a detection handshake, the dual-beam user terminal uses the backup channel to adjust its alignment to another backup satellite and repeats steps 1 to 5 until all backup satellites are polled and detected.

5. The high-resilience anti-interference satellite communication method based on dual-beam user terminals and multiple satellites according to claim 4, characterized in that: In step 2, the main control unit divides multiple channels into three states: standby, emergency, and emergency according to the channel quality. When the receiving bit error rate meets the mission requirements, the channel states are sorted according to the receiving signal-to-noise ratio; the communication satellite in the standby state is preferentially selected as the backup satellite, and when the communication satellite in the standby state is interrupted by interference, the communication satellite in the emergency state is selected as the backup satellite; when the communication satellite in the emergency state is interrupted by interference, the communication satellite in the emergency state is selected as the backup satellite.

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