Satellite-borne wireless communication system network clock and system clock synchronization method and system

Abstract

The invention provides a satellite-borne wireless communication system network clock and system clock synchronization method and system, and the system comprises a wireless communication node which is composed of a wireless node controller, a wireless transceiver chip and an antenna, and a satellite-borne terminal single machine which is in wired connection with the wireless communication node to form a wireless terminal single machine. And the plurality of wireless terminal single machines form a satellite-borne wireless communication system. And the reference node periodically broadcasts a synchronization message frame carrying own time information, and the node to be synchronized synchronizes the local time to the reference node to complete synchronization of the network clock and the system clock. According to the invention, a one-way message transmission and linear fitting mode is adopted, and high time synchronization precision is obtained with low communication overhead.

Description

Technical Field

[0001] The present invention relates to the technical field of short - range wireless communication for satellite bus networks, and specifically, to a method and system for synchronizing network clocks and system clocks in an on - satellite wireless communication system network. Background Art

[0002] Various single - machine devices inside a satellite are usually interconnected by buses, serial communications, and analog interfaces. The sharp increase in service data such as on - satellite processing and mission planning has led to an increasingly complex in - satellite cable network. With the gradual development and increasing maturity of short - range wireless technologies, it has become possible to use wireless communication inside a satellite. Using wireless transmission to replace the traditional wired transmission method inside the satellite can reduce the cable weight and simplify the cable connection relationship, bringing great convenience to product testing and overall satellite integration.

[0003] Time synchronization of each system and single - machine inside the satellite is the basis for ensuring the normal operation and mission implementation of the satellite. It not only relates to the coordinated work among various satellite systems but also directly affects the accuracy of data acquisition, processing, and transmission. Different time settings among systems may lead to data loss, mission failure, and even affect the safety of the satellite. Therefore, reliable time - synchronization technologies must be adopted to ensure the time consistency and stability of each system inside the satellite.

[0004] The time of a wireless node is generated by a crystal oscillator, which drives a digital - circuit timer to represent time information in a short - cycle cyclic - counting manner, called the internal clock or network clock. Similarly, at the application end of the wireless node, a clock circuit generates time information for representing the time of the external physical world, called the external clock or system clock. Internal - clock synchronization is used to ensure the consistency of data reception and transmission and serves information transmission, while external - clock synchronization is used to ensure the orderliness of actions and serves mission execution.

[0005] Through a literature search of the prior art, many methods have been proposed to achieve internal clock synchronization in wireless networks and improve synchronization accuracy. For example, the patent application No. 202410734699.8, "A Clock Synchronization Method for a Dual-Mode Communication Module", discloses a method for clock synchronization in a carrier Bluetooth dual-mode heterogeneous communication network; the patent application No. 202211239808.6, "A Clock Synchronization Method, Device, Equipment and Medium for a Wireless Sensor Network", uses a weighted average algorithm to iteratively process the weight matrix corresponding to the wireless sensor network to improve the accuracy of clock synchronization in the wireless sensor network. The patent application No. 202210482484.2, "A High-Precision Wireless Clock Synchronization Method and System Based on UWB", realizes high-precision multi-network node clock synchronization without GNSS assistance in a wireless network based on ultra-wideband timestamps. The patent application No. 202210659123.0, "A Clock Synchronization Method, Device, Equipment and Medium Based on a Wireless Network", proposes to achieve clock synchronization between slave clock devices and master clock devices through edge clock devices, effectively reducing the cost of clock synchronization. The patent application No. 202010362722.7, "A Clock Synchronization Method and System for a Wireless Network Based on the IEEE1588 Protocol", inputs the time deviation and network delay into a preset correction formula to obtain the corrected time, and uses the corrected time to adjust the slave clock to improve the accuracy of clock synchronization.

[0006] The above methods achieve time synchronization through multiple message exchanges between nodes, resulting in high communication overhead. When the system scale is large, they will occupy too many resources and have high requirements for the quality of the wireless channel, making it difficult to apply to the environment where the metal cabin inside the satellite is blocked. In addition, all the above methods only achieve the synchronization of the internal clock of the network and do not involve the clock synchronization of the system. Summary of the Invention

[0007] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method and system for synchronizing the network clock and system clock of a spaceborne wireless communication system.

[0008] According to a method for synchronizing the network clock and system clock of a spaceborne wireless communication system provided by the present invention, it includes:

[0009] Step S1: In a spaceborne wireless communication system, define a single wireless terminal as a clock synchronization reference node, and other single wireless terminals as nodes to be synchronized;

[0010] Step S2: The reference node periodically broadcasts a synchronization message frame carrying its own time information, and the nodes to be synchronized synchronize their local time to the reference node to complete the wireless network clock synchronization and system clock synchronization;

[0011] The wireless network clock synchronization realizes the clock synchronization of wireless communication nodes, and the system clock synchronization realizes the clock synchronization of single wireless terminals.

[0012] Preferably, the spaceborne wireless communication system includes: a wireless communication node composed of a wireless node controller, a wireless transceiver chip, and an antenna, a spaceborne terminal single unit, and a wireless communication node are connected by wire to form a wireless terminal single unit, and a plurality of wireless terminal single units form a spaceborne wireless communication system.

[0013] Preferably, the physical layer frame format is adopted when transmitting the synchronization message frame; the physical layer frame format includes a preamble, a physical layer frame header, and a physical layer frame application data field;

[0014] Among them, the physical layer frame application data field includes a clock synchronization cycle sequence number and reference time information;

[0015] The clock synchronization cycle sequence number is used to determine the continuity of the synchronization message frame and calculate the number of message frames lost by the node to be synchronized when a wireless communication anomaly occurs;

[0016] The reference time information includes the network clock and system clock of the reference node and is used to calculate the network clock and system clock deviation between the node to be synchronized and the reference node.

[0017] Preferably, the method includes: the reference node triggers the acquisition of the local timestamp according to the synchronization message frame transmission status interrupt signal, and sends the acquired local timestamp as the reference time information of the synchronization message frame application data field in the next synchronization cycle; the node to be synchronized triggers the acquisition of the local timestamp according to the synchronization message frame reception status interrupt signal;

[0018] Among them, the transmission status interrupt information includes:

[0019] At the sending end, the preamble transmission completion signal fed back by the wireless transceiver chip to the wireless node controller is used as the transmission status interrupt signal; at the receiving end, the preamble detection signal fed back by the wireless transceiver chip to the wireless node controller is used as the frame reception status interrupt signal;

[0020] Or at the sending end, the physical layer header transmission completion signal fed back by the wireless transceiver chip to the node controller is used as the transmission status interrupt signal; at the receiving end, the physical layer header detection signal fed back by the wireless transceiver chip to the node controller is used as the frame reception status interrupt signal;

[0021] Or at the sending end, the frame transmission completion signal fed back by the wireless transceiver chip to the node controller is used as the transmission status interrupt signal; at the receiving end, the frame reception completion signal fed back by the wireless transceiver chip to the node controller is used as the frame reception status interrupt signal.

[0022] Preferably, the wireless network clock synchronization includes:

[0023] Step S2.1: At the start of the clock synchronization period, the reference wireless node controller constructs a synchronization message frame by using the sequence number of the previous clock synchronization period incremented by one and the reference node timestamp triggered by the transmission status interrupt signal obtained in the previous period.

[0024] Step S2.2: The reference wireless node controller writes the synchronization message frame to the reference wireless transceiver chip. After the frame writing is completed, frame transmission is started, and the antenna begins to transmit the synchronization message frame outward.

[0025] Step S2.3: When the preamble transmission is completed, the physical layer frame header transmission is completed, or the synchronization message frame transmission is completed, the reference node wireless transceiver chip feeds back a transmission status interrupt signal to the reference wireless node controller.

[0026] Step S2.4: When the reference wireless node controller receives the transmission status interrupt signal, it triggers the acquisition of the local timestamp for constructing the synchronization message frame of the next period.

[0027] Step S2.5: When the preamble, physical layer frame header, or frame reception is detected as completed, the wireless transceiver chip of the node to be synchronized feeds back a reception status interrupt signal to the wireless node controller to be synchronized.

[0028] Step S2.6: When the wireless node controller to be synchronized receives the reception status interrupt signal, it triggers the acquisition of the local timestamp, stores the reference node transmission timestamp carried in the synchronization message frame and the acquired reception timestamp in the network clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

[0029] Preferably, the system clock synchronization includes:

[0030] Step S2.7: At the start of the clock synchronization period, the on-board terminal single unit of the reference node generates a local system timestamp and transmits it to the reference wireless node controller.

[0031] Step S2.8: The reference wireless node controller constructs a synchronization message frame by using the sequence number of the previous synchronization period incremented by one and the system timestamp.

[0032] Step S2.9: The reference wireless node controller writes the synchronization message frame data to the wireless transceiver chip. After the frame writing is completed, frame transmission is started, and the antenna begins to transmit the synchronization message frame outward.

[0033] Step S2.10: After receiving the synchronization message frame, the wireless transceiver chip of the node to be synchronized transmits it to the wireless node controller to be synchronized.

[0034] Step S2.11: After receiving a complete and correct synchronization message frame, the controller of the node to be synchronized transmits it to the on-board terminal single unit of the node to be synchronized.

[0035] Step S2.12: The on-board terminal single unit of the node to be synchronized obtains the local system timestamp, stores the reference node sending system timestamp carried in the synchronization message frame and the system timestamp obtained locally in the system clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

[0036] Preferably, the node to be synchronized in the on-board wireless communication system independently maintains a network clock synchronization time table and a system clock synchronization time table; after the synchronization time table is full, it shifts the synchronization time table according to the first-in-first-out rule and continues to store the sending timestamp and receiving timestamp of the latest synchronization period.

[0037] Preferably, the method further includes: when the synchronization period serial number in the application data field of the latest received synchronization message frame is not continuous with the synchronization period serial number in the application data field of the previously received synchronization message frame, two processing methods of discarding or interpolation are adopted;

[0038] The discarding processing method includes: the receiving end ignores the reference time information in the lost synchronization message frame and directly writes the sending timestamp and receiving timestamp obtained in this period into the synchronization time table;

[0039] The interpolation processing method includes: the receiving end calculates the time intervals between the sending timestamp and receiving timestamp respectively according to the sending timestamp and receiving timestamp stored latest in the synchronization time table and the sending timestamp and receiving timestamp obtained in this period, determines the number of interpolation according to the number of lost frames of the synchronization message frame, calculates the interpolation step size, and writes the interpolation calculation results into the synchronization time table in sequence.

[0040] According to an on-board wireless communication system network clock and system clock synchronization system provided by the present invention, it includes:

[0041] Module M1: In the on-board wireless communication system, a wireless terminal single unit is defined as a clock synchronization reference node, and other wireless terminal single units are nodes to be synchronized;

[0042] Module M2: The reference node periodically broadcasts a synchronization message frame carrying its own time information, and the node to be synchronized synchronizes the local time to the reference node to complete the wireless network clock synchronization and system clock synchronization;

[0043] The wireless network clock synchronization realizes the clock synchronization of wireless communication nodes, and the system clock synchronization realizes the clock synchronization of wireless terminal single units.

[0044] Preferably, the on-board wireless communication system includes: a wireless communication node composed of a wireless node controller, a wireless transceiver chip and an antenna, a wireless terminal single unit composed of a wired connection between an on-board terminal single unit and the wireless communication node, and several wireless terminal single units form an on-board wireless communication system;

[0045] The physical layer frame format is adopted when transmitting the synchronization message frame; the physical layer frame format includes a preamble, a physical layer frame header, and a physical layer frame application data field;

[0046] Wherein, the physical layer frame application data field includes a clock synchronization cycle serial number and reference time information;

[0047] The clock synchronization cycle serial number is used to determine the continuity of the synchronization message frame and calculate the number of lost message frames of the node to be synchronized when a wireless communication anomaly occurs;

[0048] The reference time information includes the network clock and system clock of the reference node and is used to calculate the network clock and system clock deviation between the node to be synchronized and the reference node;

[0049] The wireless network clock synchronization includes:

[0050] Module M2.1: At the start of the clock synchronization cycle, the reference wireless node controller constructs a synchronization message frame by using the previous cycle clock synchronization cycle serial number plus one and the reference node timestamp triggered by the previous cycle transmission status interrupt signal;

[0051] Module M2.2: The reference wireless node controller writes the synchronization message frame into the reference wireless transceiver chip. After the frame writing is completed, the frame transmission is started, and the antenna starts to transmit the synchronization message frame outward;

[0052] Module M2.3: The reference node wireless transceiver chip feeds back a transmission status interrupt signal to the reference wireless node controller when the preamble transmission is completed, the physical layer frame header transmission is completed, or the synchronization message frame transmission is completed;

[0053] Module M2.4: When the reference wireless node controller receives the transmission status interrupt signal, it triggers the acquisition of the local timestamp for constructing the synchronization message frame of the next cycle;

[0054] Module M2.5: The wireless transceiver chip of the node to be synchronized feeds back a reception status interrupt signal to the wireless node controller to be synchronized when detecting the preamble, the physical layer frame header, or the frame reception completion;

[0055] Module M2.6: When the wireless node controller to be synchronized receives the reception status interrupt signal, it triggers the acquisition of the local timestamp, stores the reference node transmission timestamp carried in the synchronization message frame and the acquired reception timestamp in the network clock synchronization time table for linear fitting, and calculates the time deviation from the reference node;

[0056] The system clock synchronization includes:

[0057] Module M2.7: At the start of the clock synchronization cycle, the on-board terminal single machine of the reference node generates a local system timestamp and transmits it to the reference wireless node controller;

[0058] Module M2.8: The reference wireless node controller constructs a synchronization message frame by using the synchronization cycle serial number of the previous cycle plus one and the system timestamp;

[0059] Module M2.9: The reference wireless node controller writes the synchronization message frame data into the wireless transceiver chip. After the frame writing is completed, the frame transmission is started, and the antenna starts to send the synchronization message frame outward;

[0060] Module M2.10: After receiving the synchronization message frame, the wireless transceiver chip of the node to be synchronized passes it to the wireless node controller to be synchronized;

[0061] Module M2.11: After receiving a complete and correct synchronization message frame, the controller of the node to be synchronized passes it to the on-board terminal single unit of the node to be synchronized;

[0062] Module M2.12: The on-board terminal single unit of the node to be synchronized obtains the local system timestamp, stores the system timestamp sent by the reference node carried in the synchronization message frame and the system timestamp obtained locally in the system clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] 1. In addition to completing the internal network clock synchronization to ensure the consistency of data transmission, the present invention also realizes the synchronization between the system clock and the external physical time to ensure the orderliness of task execution;

[0065] 2. Starting from the clock model, the present invention adopts the method of unidirectional information transmission and uses mathematical methods to calculate the time deviation, reducing the communication overhead of synchronization messages. Moreover, unidirectional communication is more suitable for the channel conditions in the on-board metal shielding environment.

[0066] 3. The present invention adopts the methods of unidirectional message transmission and linear fitting to obtain high time synchronization accuracy with low communication overhead. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Other features, objects and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0068] Figure 1 It is a schematic diagram of an on-board wireless communication system.

[0069] Figure 2 It is a schematic diagram of the physical layer format of the synchronization message frame.

[0070] Figure 3 It is a flowchart of network clock synchronization.

[0071] Figure 4It is a flowchart for system clock synchronization. Specific Embodiment

[0072] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those of ordinary skill in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0073] Embodiment 1

[0074] According to a method for synchronizing the network clock and system clock of a spaceborne wireless communication system provided by the present invention, as Figure 1 shown, a wireless communication node is composed of a wireless node controller, a wireless transceiver chip, and an antenna. A spaceborne terminal single machine and a wireless communication node are connected by wire to form a wireless terminal single machine. N wireless terminal single machines form a spaceborne wireless communication system;

[0075] In the spaceborne wireless communication system, the wireless terminal single machine 1 is defined as the clock synchronization reference node, and the wireless terminal single machines 2 to n are the nodes to be synchronized; the reference node periodically broadcasts a synchronization message frame carrying its own time information, and the nodes to be synchronized synchronize their local time to the reference node to complete clock synchronization;

[0076] The clock synchronization includes wireless network clock synchronization and system clock synchronization. The wireless network clock synchronization realizes the clock synchronization of wireless communication nodes, and the system clock synchronization realizes the clock synchronization of wireless terminal single machines;

[0077] Specifically, for the synchronization message frame, the physical layer frame format is as Figure 2 shown, and it includes a preamble, a physical layer frame header, and a physical layer frame application data field;

[0078] The physical layer frame application data field includes a synchronization cycle sequence number and a reference time information field;

[0079] The clock synchronization cycle sequence number is used to determine the continuity of the synchronization message frame and calculate the number of message frames lost by the nodes to be synchronized when wireless communication is abnormal;

[0080] The reference time information includes the network clock and system clock of the reference node and is used to calculate the network clock and system clock deviations between the nodes to be synchronized and the reference node.

[0081] Specifically, for the network clock synchronization, the reference node triggers the acquisition of the local timestamp according to the synchronization message frame sending status interrupt signal, and uses the acquired local timestamp as the reference time information in the application data field of the synchronization message frame to be sent in the next synchronization period; the node to be synchronized triggers the acquisition of the local timestamp according to the synchronization message frame receiving status interrupt signal.

[0082] Optionally, at the sending end, the preamble transmission completion signal fed back by the wireless transceiver chip to the node controller is used as the sending status interrupt signal, and at the receiving end, the preamble detection signal fed back by the wireless transceiver chip to the node controller is used as the frame receiving status interrupt signal.

[0083] Optionally, at the sending end, the physical layer header transmission completion signal fed back by the wireless transceiver chip to the node controller is used as the sending status interrupt signal, and at the receiving end, the physical layer header detection signal fed back by the wireless transceiver chip to the node controller is used as the frame receiving status interrupt signal.

[0084] Optionally, at the sending end, the frame transmission completion signal fed back by the wireless transceiver chip to the node controller is used as the sending status interrupt signal, and at the receiving end, the frame receiving completion signal fed back by the wireless transceiver chip to the node controller is used as the frame receiving status interrupt signal.

[0085] Specifically, the steps of the wireless network clock synchronization are as Figure 3 shown and include:

[0086] (1) At the start of the clock synchronization period, the reference node controller constructs a synchronization message frame by using the synchronization period sequence number of the previous period plus one and the reference node timestamp triggered by the sending status interrupt signal of the previous period.

[0087] (2) The reference node controller writes the synchronization message frame into the wireless transceiver chip. After the frame writing is completed, the frame transmission is started, and the antenna starts to send the synchronization message frame outward.

[0088] (3) When the preamble transmission is completed, the physical layer header transmission is completed, or the synchronization message frame transmission is completed, the reference node wireless transceiver chip feeds back the sending status interrupt signal to the reference node controller.

[0089] (4) When the reference node controller receives the sending status interrupt signal, it triggers the acquisition of the local timestamp for constructing the synchronization message frame of the next period.

[0090] (5) When the wireless transceiver chip of the node to be synchronized detects the preamble, detects the physical layer header, or detects the frame receiving completion, it feeds back the receiving status interrupt signal to the controller of the node to be synchronized.

[0091] (6) When the node controller to be synchronized receives the reception status interrupt signal, it triggers the acquisition of the local timestamp, stores the reference node transmission timestamp carried in the synchronization message frame and the acquired reception timestamp in the network clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

[0092] Specifically, the steps of system clock synchronization are as Figure 4 shown, including:

[0093] (1) At the start of the clock synchronization cycle, the on-board terminal single unit of the reference node generates a local system timestamp and transmits it to the reference node controller;

[0094] (2) The reference node controller constructs a synchronization message frame by using the synchronization cycle sequence number of the previous cycle plus one and the system timestamp;

[0095] (3) The reference node controller writes the synchronization message frame data into the wireless transceiver chip. After the frame writing is completed, it starts frame transmission, and the antenna starts to transmit the synchronization message frame outward;

[0096] (4) After the wireless transceiver chip of the node to be synchronized receives the synchronization message frame, it transmits it to the node controller to be synchronized;

[0097] (5) After the node controller to be synchronized receives a complete and correct synchronization message frame, it transmits it to the on-board terminal single unit of the node to be synchronized;

[0098] (6) The on-board terminal single unit of the node to be synchronized acquires the local system timestamp, stores the reference node transmission system timestamp carried in the synchronization message frame and the locally acquired system timestamp in the system clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

[0099] Specifically, the depth of the synchronization time table can be customized and changed. The nodes to be synchronized in the on-board wireless communication system independently maintain a network clock synchronization time table and a system clock synchronization time table, and the table depth is K for both; after the synchronization time table is full, it is shifted according to the first-in first-out rule, and the transmission timestamp and reception timestamp of the latest synchronization cycle are continuously stored;

[0100] Specifically, for the method of synchronizing the network clock and system clock of the on-board wireless communication system, when the synchronization cycle sequence number of the latest received synchronization message frame is not continuous with the synchronization cycle sequence number of the previously received synchronization message frame, two processing methods of discarding or interpolation can be adopted;

[0101] For the discard processing method, the receiving end ignores the reference time information in the lost synchronization message frame and directly fills the transmission timestamp and reception timestamp obtained in this cycle into the synchronization time table;

[0102] For the interpolation processing method, the receiving end calculates the time intervals between the transmission timestamps and the reception timestamps respectively according to the latest stored transmission timestamp, reception timestamp in the synchronization time table and the transmission timestamp, reception timestamp obtained in this period, determines the number of interpolation values according to the number of lost frames of the synchronization message frame, calculates the interpolation step, and writes the interpolation calculation results into the synchronization time table in sequence.

[0103] The present invention also provides a synchronization system for the network clock and the system clock of a spaceborne wireless communication system. The synchronization system for the network clock and the system clock of the spaceborne wireless communication system can be implemented by executing the process steps of the synchronization method for the network clock and the system clock of the spaceborne wireless communication system. That is, those skilled in the art can understand the synchronization method for the network clock and the system clock of the spaceborne wireless communication system as a preferred implementation manner of the synchronization system for the network clock and the system clock of the spaceborne wireless communication system.

[0104] Those skilled in the art know that in addition to implementing the systems, devices and their respective modules provided by the present invention in the form of pure computer-readable program codes, the method steps can be logically programmed to enable the systems, devices and their respective modules provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same program. Therefore, the systems, devices and their respective modules provided by the present invention can be regarded as a kind of hardware components, and the modules included therein for implementing various programs can also be regarded as the structures within the hardware components; the modules for implementing various functions can also be regarded as either software programs for implementing the methods or the structures within the hardware components.

[0105] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for synchronizing the network clock and the system clock of a spaceborne wireless communication system, characterized in that Including: Step S1: In a spaceborne wireless communication system, define a single wireless terminal as a clock synchronization reference node, and other single wireless terminals as nodes to be synchronized. Step S2: The reference node periodically broadcasts a synchronization message frame carrying its own time information, and the nodes to be synchronized synchronize their local times to the reference node to complete wireless network clock synchronization and system clock synchronization. The wireless network clock synchronization realizes the clock synchronization of wireless communication nodes, and the system clock synchronization realizes the clock synchronization of single wireless terminals.

2. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 1, characterized in that, The spaceborne wireless communication system includes: a wireless communication node composed of a wireless node controller, a wireless transceiver chip, and an antenna; a single spaceborne terminal and the wireless communication node are connected by wire to form a single wireless terminal; and several single wireless terminals form a spaceborne wireless communication system.

3. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 2, wherein When transmitting the synchronization message frame, a physical layer frame format is adopted; the physical layer frame format includes a preamble, a physical layer frame header, and a physical layer frame application data field. Among them, the physical layer frame application data field includes a clock synchronization cycle serial number and reference time information. The clock synchronization cycle serial number is used to determine the continuity of the synchronization message frame and calculate the number of lost message frames of the nodes to be synchronized in case of wireless communication anomalies. The reference time information includes the network clock and system clock of the reference node, and is used to calculate the network clock and system clock deviations between the nodes to be synchronized and the reference node.

4. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 3, wherein The method includes: the reference node triggers the acquisition of a local timestamp according to the synchronization message frame transmission status interrupt signal, and uses the acquired local timestamp as the reference time information of the synchronization message frame application data field in the next synchronization cycle for transmission; the nodes to be synchronized trigger the acquisition of a local timestamp according to the synchronization message frame reception status interrupt signal. Among them, the transmission status interrupt information includes: At the sending end, use the preamble transmission completion signal fed back by the wireless transceiver chip to the wireless node controller as the transmission status interrupt signal; at the receiving end, use the preamble detection signal fed back by the wireless transceiver chip to the wireless node controller as the frame reception status interrupt signal. Or at the sending end, use the physical layer header transmission completion signal fed back by the wireless transceiver chip to the node controller as the transmission status interrupt signal; at the receiving end, use the physical layer header detection signal fed back by the wireless transceiver chip to the node controller as the frame reception status interrupt signal. Or at the sending end, use the frame transmission completion signal fed back by the wireless transceiver chip to the node controller as the transmission status interrupt signal; at the receiving end, use the frame reception completion signal fed back by the wireless transceiver chip to the node controller as the frame reception status interrupt signal.

5. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 4, characterized in that, The wireless network clock synchronization includes: Step S2.1: At the start of a clock synchronization cycle, the reference wireless node controller constructs a synchronization message frame by using the clock synchronization cycle serial number of the previous cycle plus one and the reference node timestamp triggered by the transmission status interrupt signal of the previous cycle. Step S2.2: The reference wireless node controller writes the synchronization message frame to the reference wireless transceiver chip. After the frame writing is completed, the frame transmission is started, and the antenna starts to send the synchronization message frame outward. Step S2.3: When the transmission of the preamble, the transmission of the physical layer frame header, or the transmission of the synchronization message frame is completed, the reference node wireless transceiver chip feeds back a transmission status interrupt signal to the reference wireless node controller; Step S2.4: When the reference wireless node controller receives the transmission status interrupt signal, it triggers the acquisition of the local timestamp for constructing the synchronization message frame in the next cycle; Step S2.5: When the wireless transceiver chip of the node to be synchronized detects the preamble, the physical layer frame header, or the completion of frame reception, it feeds back a reception status interrupt signal to the wireless node controller to be synchronized; Step S2.6: When the wireless node controller to be synchronized receives the reception status interrupt signal, it triggers the acquisition of the local timestamp, stores the reference node transmission timestamp carried in the synchronization message frame and the acquired reception timestamp in the network clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

6. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 4, characterized in that, The system clock synchronization includes: Step S2.7: At the start of the clock synchronization cycle, the on-board terminal single unit of the reference node generates a local system timestamp and transmits it to the reference wireless node controller; Step S2.8: The reference wireless node controller constructs a synchronization message frame using the synchronization cycle number of the previous cycle plus one and the system timestamp; Step S2.9: The reference wireless node controller writes the synchronization message frame data into the wireless transceiver chip. After the frame writing is completed, it starts frame transmission, and the antenna starts to transmit the synchronization message frame outward; Step S2.10: After the wireless transceiver chip of the node to be synchronized receives the synchronization message frame, it transmits it to the wireless node controller to be synchronized; Step S2.11: After the wireless node controller to be synchronized receives a complete and correct synchronization message frame, it transmits it to the on-board terminal single unit of the node to be synchronized; Step S2.12: The on-board terminal single unit of the node to be synchronized acquires the local system timestamp, stores the reference node transmission system timestamp carried in the synchronization message frame and the locally acquired system timestamp in the system clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

7. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 5 or 6, characterized in that The node to be synchronized in the on-board wireless communication system independently maintains a network clock synchronization time table and a system clock synchronization time table; after the synchronization time table is full, it shifts the synchronization time table according to the first-in-first-out rule and continues to store the transmission timestamp and reception timestamp of the latest synchronization cycle.

8. The method for synchronizing the network clock and the system clock of the spaceborne wireless communication system according to claim 3, wherein The method further includes: when the synchronization cycle number in the application data field of the latest received synchronization message frame is not continuous with the synchronization cycle number in the application data field of the previously received synchronization message frame, two processing methods of discarding or interpolation are adopted; The discarding processing method includes: the receiving end ignores the reference time information in the lost synchronization message frame and directly writes the transmission timestamp and reception timestamp acquired in this cycle into the synchronization time table; The interpolation processing method includes: the receiving end calculates the time intervals between the transmission timestamp and the reception timestamp respectively according to the latest stored transmission timestamp, reception timestamp in the synchronization time table and the transmission timestamp, reception timestamp acquired in this cycle, determines the number of interpolation according to the number of lost synchronization message frames, calculates the interpolation step size, and writes the interpolation calculation results into the synchronization time table in sequence.

9. A network clock and system clock synchronization system for a spaceborne wireless communication system, characterized in that, including: Module M1: In a spaceborne wireless communication system, a single wireless terminal is defined as a clock synchronization reference node, and other single wireless terminals are nodes to be synchronized; Module M2: The reference node periodically broadcasts a synchronization message frame carrying its own time information. The nodes to be synchronized synchronize their local time to the reference node to complete the wireless network clock synchronization and the system clock synchronization; The wireless network clock synchronization realizes the clock synchronization of wireless communication nodes, and the system clock synchronization realizes the clock synchronization of single wireless terminals.

10. The network clock and system clock synchronization system of the spaceborne wireless communication system according to claim 9, characterized in that, The spaceborne wireless communication system includes: A wireless communication node composed of a wireless node controller, a wireless transceiver chip and an antenna. Single spaceborne terminals and wireless communication nodes are connected by wire to form single wireless terminals, and several single wireless terminals form a spaceborne wireless communication system; When transmitting the synchronization message frame, the physical layer frame format is adopted; the physical layer frame format includes a preamble, a physical layer frame header, and a physical layer frame application data field; Among them, the physical layer frame application data field includes a clock synchronization cycle serial number and reference time information; The clock synchronization cycle serial number is used to determine the continuity of the synchronization message frame and calculate the number of message frames lost by the nodes to be synchronized when a wireless communication anomaly occurs; The reference time information includes the network clock and system clock of the reference node, and is used to calculate the network clock and system clock deviation between the nodes to be synchronized and the reference node; The wireless network clock synchronization includes: Module M2.1: At the start of a clock synchronization cycle, the reference wireless node controller constructs a synchronization message frame by using the clock synchronization cycle serial number of the previous cycle plus one and the reference node timestamp triggered by the transmission status interrupt signal of the previous cycle; Module M2.2: The reference wireless node controller writes the synchronization message frame to the reference wireless transceiver chip. After the frame writing is completed, the frame transmission is started, and the antenna starts to send the synchronization message frame outward; Module M2.3: The reference node wireless transceiver chip feeds back a transmission status interrupt signal to the reference wireless node controller when the preamble transmission is completed, the physical layer frame header transmission is completed, or the synchronization message frame transmission is completed; Module M2.4: When the reference wireless node controller receives the transmission status interrupt signal, it triggers the acquisition of a local timestamp for constructing the synchronization message frame of the next cycle; Module M2.5: The wireless transceiver chip of the node to be synchronized feeds back a reception status interrupt signal to the wireless node controller to be synchronized when it detects the preamble, the physical layer frame header, or the frame reception is completed; Module M2.6: When the wireless node controller to be synchronized receives the reception status interrupt signal, it triggers the acquisition of a local timestamp, stores the reference node transmission timestamp carried in the synchronization message frame and the acquired reception timestamp in the network clock synchronization time table for linear fitting, and calculates the time deviation from the reference node; The system clock synchronization includes: Module M2.7: At the start of a clock synchronization cycle, the single spaceborne terminal of the reference node generates a local system timestamp and transfers it to the reference wireless node controller; Module M2.8: The reference wireless node controller constructs a synchronization message frame by using the synchronization cycle serial number of the previous cycle plus one and the system timestamp; Module M2.9: The reference wireless node controller writes the synchronous message frame data to the wireless transceiver chip. After the frame writing is completed, the frame transmission is started, and the antenna begins to send the synchronous message frame outward; Module M2.10: After the wireless transceiver chip of the node to be synchronized receives the synchronous message frame, it is passed to the wireless node controller to be synchronized; Module M2.11: After the controller of the node to be synchronized receives the complete and correct synchronous message frame, it is passed to the on-board terminal single unit of the node to be synchronized; Module M2.12: The on-board terminal single unit of the node to be synchronized obtains the local system timestamp, stores the reference node transmission system timestamp carried in the synchronous message frame and the locally obtained system timestamp in the system clock synchronization time table for linear fitting, and calculates the time deviation from the reference node.

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