Satellite communication system and communication method with multi-mode capability

Abstract

The application provides a satellite communication system and method with multi-mode capability, belonging to the technical field of satellite communication. The signal processing module of the system comprises a load control unit and a baseband processing unit, the former is responsible for beam-related calculation, transmission rate control, antenna channel on-off control, etc., and the latter processes uplink and downlink signals and supports multiple modes in downlink. The frequency conversion processing module has up-conversion and down-conversion channels for processing transmitting and receiving signals respectively. The wide-beam receiving antenna is responsible for receiving uplink data. The phased array transmitting antenna is responsible for transmitting downlink data, has high gain and fast pointing adjustment, and supports multiple modes. In the communication method, the satellite transmits and receives by default, and the transmission serves as a beacon to assist user acquisition. The application can flexibly switch working modes, improve telemetry downlink transmission capability and information broadcast efficiency, and meet diversified communication requirements.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of satellite communication, and particularly relates to a satellite communication system with multi-mode capability and a communication method. BACKGROUND

[0002] In the traditional satellite communication system, the satellite measurement and control has been in a relatively fixed operation mode for a long time: the satellite measurement and control system is in a default on state under the receiving module, and its core task is to receive various instructions from the ground; the transmitting module is turned on according to the task planning; and the receiving and transmitting module generally uses a wide beam antenna. This architecture has played an important role in a specific stage of technical development, but with the diversification and complication of communication needs, its single function has become increasingly prominent, and obvious deficiencies have been exposed in multiple key links. In terms of telemetry downlink capability, the gain and directivity of signal transmission are greatly restricted due to the inherent performance of the wide beam antenna, which directly leads to a low rate of telemetry data downlink, and in a complex electromagnetic environment, the anti-interference capability is weak, and data loss or transmission errors are prone to occur. In terms of information broadcast function, the traditional mode has significant limitations in flexibility and pertinence, and it is difficult to meet the different needs of key users and ordinary users; key users usually have high requirements for the real-time performance, security and transmission rate of information, while ordinary users pay more attention to the coverage range of information and the convenience of obtaining information. SUMMARY

[0003] The application aims to provide a satellite communication system with multi-mode communication capability and a communication method, so as to overcome the defects of the traditional satellite system in telemetry downlink and information broadcast, and realize more efficient, flexible and targeted satellite communication. Through the innovative hardware architecture and process design, the system realizes flexible switching and optimized configuration of the measurement and control function and the information broadcast function, aiming to fundamentally improve the overall performance and adaptability of satellite communication, and meet the growing diversified communication needs.

[0004] The application is implemented as follows:

[0005] A satellite communication system with multi-mode capability, comprising a signal processing module, a frequency conversion processing module, a wide beam receiving antenna and a phased array transmitting antenna.

[0006] The signal processing module comprises a load control unit and a baseband processing unit; the load control unit is responsible for receiving the TT&C command injected by the ground station, and completes the calculation of the beam coverage range and the beam pointing according to the ephemeris and the star posture data broadcast by the satellite platform and the user position reported by the baseband processing unit, controls the downlink transmission rate of the baseband processing unit and the working mode and the beam pointing of the phased array transmitting antenna; the load control unit completes the switching of the channels of the phased array transmitting antenna according to the coverage range or the TT&C link margin; the load control unit adjusts the power or the beam through the phased array transmitting antenna under the condition of meeting the existing communication demand; the baseband processing unit is used for completing the uplink signal processing and the downlink signal processing; the uplink signal supports high, medium and low carrier signal processing, and respectively completes the analysis of the TT&C command injected by the ground station, the user network access information processing and the user network exit information processing; wherein, the low frequency carrier signal adopts a spread spectrum processing mode, different network access users complete the network exit information reporting through different spread spectrum codes, and information conflict is avoided; the TT&C command carried by the high frequency carrier signal controls the opening and closing of the medium and low carrier signal processing functions; the downlink signal processing supports the flexible switching of multiple modes through the injected TT&C command, including the beacon mode, the telemetry data transmission mode and the information broadcast mode.

[0007] The frequency conversion processing module comprises an up-conversion channel and a down-conversion channel; the up-conversion channel is used for completing the up-conversion processing of the transmitting signal of the signal processing module, and sending the signal to the phased array transmitting antenna; the down-conversion channel realizes the reception of the signal through the wide beam receiving antenna, completes the amplification and the down-conversion, and then sends the signal to the baseband processing unit;

[0008] The wide beam receiving antenna adopts an omnidirectional antenna form, receives the wireless signal and sends the signal to the down-conversion channel of the frequency conversion processing module.

[0009] The phased array transmitting antenna adopts a phased array antenna form and is independently composed of multiple channels; the phased array transmitting antenna receives the signal of the up-conversion channel of the frequency conversion processing module and performs wireless output.

[0010] Further, the load control unit receives the receiving level and the signal-to-noise ratio margin injected by the ground station through the TT&C command, and adjusts the EIRP of the phased array antenna according to the margin condition and the coverage range.

[0011] Further, the downlink signal processing of the baseband processing unit sends the unique broadcast information generated by the satellite in combination with the user identifier and the encryption strategy and the spread spectrum code word used during the network access and the network exit to the user in the information broadcast mode.

[0012] Further, the phased array transmitting antenna is in a default state with part of the channels turned on, is used for beacon transmission in a large coverage range, assists the high dynamic user in capturing or the large aperture antenna in stable tracking adjustment, and can adjust the beam width and the EIRP through the switching of the channels.

[0013] A communication method based on a satellite communication system, implemented by the above-mentioned satellite communication system with multi-mode capability, the satellite transmission and reception are both turned on by default, the receiving adopts a wide-beam receiving antenna to receive instructions, the transmitting adopts a phased array transmitting antenna for beacon transmission, telemetry transmission or information broadcast, and the measurement and control function mode and the information broadcast mode are switched by instructions;

[0014] The execution of the measurement and control function mode includes the following processes:

[0015] Step 101, the ground station points to the satellite in advance according to the satellite ephemeris, and performs a micro-adjustment according to the beacon transmission signal to ensure the alignment of the satellite and the ground antenna;

[0016] Step 102, after the pointing adjustment is completed, the ground station successively uploads the geographical position and receiving capacity of the ground station, information, and sends a working mode switching instruction;

[0017] Step 103, after the satellite receives the instruction information from the ground station through the wide-beam receiving antenna, the channels of the phased array transmitting antenna are all opened, and the transmitting power reaches the maximum;

[0018] Step 104, the payload control unit in the signal processing module performs angle calculation according to the position of the ground station and the position and attitude of the satellite itself to realize the staring at the ground station;

[0019] Step 105, the baseband processing unit in the signal processing module is switched to the telemetry fast downlink working mode, and selects a suitable downlink rate according to the receiving capacity of the ground station;

[0020] Step 106, the satellite performs telemetry fast downlink, and the ground station acquires the telemetry data of the satellite; during the transmission process, the ground station uploads the information of the receiving level and the signal-to-noise ratio margin through the measurement and control instruction, and the payload control unit adjusts the EIRP of the phased array according to the margin to reduce the power consumption of the whole satellite while ensuring the transmission rate.

[0021] Further, the information broadcast mode includes ordinary user broadcast and key user broadcast;

[0022] The execution of the ordinary user broadcast includes the following processes:

[0023] Step 201, when a user needs to receive broadcast information, the user sends the own information to the satellite; different users adopt a contention access mode;

[0024] Step 202, after receiving the information, the satellite confirms the correct received user's own information, and judges whether the user is within the network service range;

[0025] Step 203, if in the network service range, confirm whether the current transmission coverage range supports the new user, support the new user to proceed to step 204, do not support the new user to proceed to step 205; if not in the network service range, exit the process;

[0026] Step 204, the satellite sends the unique broadcast information generated by combining the user identification and encryption strategy and the spread spectrum code word used when logging off to the user; the user decrypts, receives and uses the broadcast information according to the encryption strategy;

[0027] Step 205, judge the relative angle of the satellite and the user, proceed to table lookup, adjust the information rate according to the EIRP change caused by the angle change size, and complete the partial channel closing of the phased array transmitting antenna;

[0028] Step 206, after the user entering the network calculates that he will leave the coverage area or does not need to continue receiving the broadcast according to the received satellite ephemeris and his own position, report the state by combining the logging-off spread spectrum code word; after the satellite receives the logging-off information, adjust the coverage area;

[0029] The execution of the key user broadcast includes the following processes:

[0030] Step 301, when the user needs to receive the broadcast information, send his own information to the satellite;

[0031] Step 302, after the satellite receives it, confirm the correct user information received, judge whether the user is in the network service range;

[0032] Step 303, if in the network service range, the satellite calculates the link rate according to the position and receiving capacity of the user terminal, calculates the broadcast information residence period according to the size of the broadcast information, and proceeds to the next step; if not in the network service range, exit the process;

[0033] Step 304, the satellite first calculates whether the current agile coverage area supports the new user according to the user position, satellite position and beam width; if the current coverage area supports the new user, proceed to step 305; if the current coverage area does not support the new user, proceed to step 306;

[0034] Step 305, the satellite sends the unique broadcast information generated by combining the user identification and encryption strategy and the spread spectrum code word used when logging off to the user, and adjusts the residence period Tn of the beam, and the user receives and uses the broadcast information;

[0035] Step 306, a new coverage wave bit is generated for serving a new user, and the unique broadcast information generated in combination with the user identifier and encryption strategy and the spreading code word used when logging off are sent to the user; the number of wave bits changes from m to m+1, where m is the maximum ratio of satellite coverage range to beam width, and the flyback period of the beam changes from T0+T1+T2+… …+T m , to T0+T1+T2+… …+T m +T m+1 ; wherein T1, T2, T m represent the residence periods of the first, second, and mth wave bits, respectively.

[0036] Step 307, after the user calculates that it will soon leave the coverage area or does not need to continue receiving the broadcast according to the received satellite ephemeris and its own position, the state is reported in combination with the log-off spreading code word; after the satellite receives it, the coverage area is adjusted.

[0037] Compared with the prior art, the present application has the following beneficial effects:

[0038] It has working modes of remote sensing fast downlink, key user information broadcast, and ordinary user information broadcast, and can be flexibly switched according to actual needs, which can not only efficiently realize the function of measurement and control and improve the remote sensing downlink capability, but also meet the information broadcast needs of different users.

[0039] In terms of information broadcast, ordinary users and key users are distinguished, and different broadcast strategies are adopted, which improves the targeting and efficiency of the broadcast.

[0040] For the user access and log-off process, the stability of the communication and the rational use of resources are ensured by flexibly adjusting the coverage range, information rate, number of on-off channels of the phased array antenna, and the like. The transmission coverage range and beam parameters of the entire system can be dynamically adjusted according to the user access situation, which improves the adaptability and communication quality of the system and better meets the communication needs in different scenarios.

[0041] In the process design of user access and log-off, the system realizes efficient resource management through a differentiated mechanism: the user access is completed in a competitive manner in the access stage, and the satellite sends the unique broadcast information generated in combination with the user identifier and encryption strategy and the spreading code word used when logging off to the user during the access process, and the user completes the broadcast information reception and log-off according to the parsed encryption strategy and spreading code word.

[0042] To sum up, the transmission and reception of the satellite in the present application are both in the default on state, which is used for receiving instructions and transmitting beacon signals to assist the acquisition of high dynamic users. The reception adopts a wide beam antenna, and the transmission adopts a phased array antenna form, which defaults to the minimum number of channels and is powered on. The phased array antenna can adjust the channel switching and beam width. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 This is a schematic diagram illustrating the implementation principle of the satellite communication system in this invention.

[0044] Figure 2 This is a schematic diagram of the phased array transmitting antenna channel layout of the satellite communication system in this invention.

[0045] Figure 3 This is a schematic diagram illustrating the application of the satellite communication system in this invention. Detailed Implementation

[0046] The specific embodiments of the present invention will be described in detail below with reference to specific scenarios.

[0047] Reference Figure 1 The satellite communication system in this embodiment includes a signal processing module, a frequency conversion processing module, a wide-beam receiving antenna, and a phased array transmitting antenna.

[0048] Signal processing module: This module includes a payload control unit and a baseband processing unit. The payload control unit receives telemetry and control commands from the ground and calculates beam coverage and beam pointing based on satellite platform ephemeris and attitude data, as well as user positions reported by the baseband processing unit. It also controls the downlink transmission rate of the baseband processing unit and manages the operating mode and beam pointing of the phased array transmitting antenna. Simultaneously, the payload control unit switches the phased array antenna channels based on coverage area or telemetry and control link margin. While meeting existing communication requirements, the payload control unit adjusts the power or beam of the phased array transmitting antenna. The baseband processing unit mainly performs uplink and downlink signal processing. Uplink signals support high, medium, and low carrier signal processing, respectively handling ground station uplink command parsing, user network access signal processing, and user network exit information processing. Among them, low-frequency carrier signals adopt spread spectrum processing, and different network access users complete network exit through different spread spectrum codes. The uplink telemetry and control commands can be used to determine whether to enable or disable medium and low carrier signal processing functions. Downlink signal processing supports flexible switching of multiple modes through uplink telemetry and control commands, including beacon mode, telemetry data transmission mode, and information broadcast mode.

[0049] The frequency conversion processing module includes one up-conversion channel and one down-conversion channel. The up-conversion channel mainly performs up-conversion processing on the signals transmitted by the signal processing module and sends them to the phased array transmitting antenna. The down-conversion channel mainly receives the signals through a wide-beam receiving antenna, amplifies and down-converts them, and then sends them to the baseband processing unit.

[0050] Wide-beam receiving antenna: The wide-beam receiving antenna adopts an omnidirectional antenna design, featuring a large antenna beam angle and low gain. It receives wireless signals and transmits them to the down-conversion module of the frequency conversion processing module.

[0051] Phased array transmitting antenna: in the form of phased array antenna, composed of multiple channels independently, with high output power, quick and flexible pointing characteristics. The phased array transmitting antenna receives the signal of the up-conversion channel of the frequency conversion processing module and performs wireless output. Each channel of the phased array antenna has independent power-on and power-off functions, and can support the gaze mode and the agile mode. The channel layout of the phased array transmitting antenna is shown in Figure 2 .

[0052] Referring to Figure 3 , in the default boot state, the satellite transmission and reception are both in working state, the receiving adopts wide beam antenna to receive instructions, and the phased array antenna is used as a beacon transmitter to assist the acquisition of high dynamic users. The system has multiple working modes, as follows:

[0053] (I) Implementation process of the measurement and control function mode:

[0054] When the telemetry and remote control functions need to be implemented,

[0055] Step 101, the ground station points to the satellite in advance according to the satellite ephemeris, and performs a micro-adjustment of the pointing according to the beacon transmission signal to ensure the alignment of the satellite and the ground station antennas.

[0056] Step 102, after the pointing adjustment is completed, the ground station successively uploads the ground station geographic position and receiving capacity information, and sends a working mode switching instruction.

[0057] Step 103, after receiving the ground station instruction information through the wide beam receiving antenna, the satellite opens all the channels of the phased array transmitting antenna, and the transmitting power reaches the maximum.

[0058] Step 104, the payload control unit in the signal processing module calculates the angle according to the ground station position and the satellite's own position and attitude, and realizes the gaze on the ground station.

[0059] Step 105, the baseband processing unit in the signal processing module switches to the telemetry fast downlink working mode, and selects an appropriate downlink rate according to the ground station receiving capacity.

[0060] Step 106, the satellite transmits the telemetry data fast, and the ground station acquires the telemetry data of the satellite; during the transmission process, the ground station uploads the information of the receiving level and the signal-to-noise ratio margin through the measurement and control instruction, and the payload control unit adjusts the EIRP of the phased array according to the margin to reduce the overall satellite power consumption while ensuring the transmission rate.

[0061] (II) Information broadcast mode

[0062] When broadcasting information, there are two specific implementation methods: ordinary user broadcast and key user broadcast.

[0063] Ordinary user broadcast

[0064] For ordinary user broadcast, when the ground station transmits the switching relay mode instruction, the receiving antenna of the satellite is in the omnidirectional state, and the transmission is in the full-channel power-on state by default. The channels can be powered on or off to adjust the beam coverage range according to the actual needs of the user access. The satellite receiving end has a large angle coverage, although the ability is weak, but it can meet the access request of a large range of users; the transmitting end has a relatively small angle and strong ability, and its coverage range can be flexibly adjusted. The broadcast content includes satellite information, access information and various broadcast information.

[0065] When the ordinary user needs to receive broadcast information, the user's position, identity, capacity and other information are informed to the satellite through competitive access. After receiving the user information, the satellite judges whether the user is within the network service range according to the user identity. If it is within the service range, it is further confirmed whether the current transmission coverage range can support the new user. If it can support, the satellite generates access confirmation information combined with the user identity and the encryption strategy of the satellite and sends it to the user, and sends the user's spread spectrum code when the user logs out. After the user analyzes the encryption strategy, the user can normally receive and use the broadcast information. If the current coverage range does not support the new user, the satellite will adjust the broadcast information rate according to the EIRP (Equivalent Isotropic Radiated Power) change caused by the change of the relative angle with the user, and then turn off part of the array elements from outside to inside to adjust the coverage range. After that, the unique broadcast access confirmation information and the logout spread spectrum code generated by combining the user identity and the encryption strategy of the satellite are informed to the new user. When the user calculates that it will leave the coverage area or does not need to continue to receive the broadcast, the user reports the logout information through the respective spread spectrum code of the user. After receiving it, the satellite adjusts the coverage area by turning on or off the channels of the phased array transmitting antenna. The specific process is as follows:

[0066] Step 201, when the user needs to receive broadcast information, the user's information (user position, user identity, user capacity and other information) is sent to the satellite; different users use competitive access;

[0067] Step 202, after receiving, the satellite confirms the correct user information, and judges whether the user is within the network service range;

[0068] Step 203, if it is within the network service range, it is confirmed whether the current transmission coverage range supports the new user, and the new user is supported to proceed to step 204, and the new user is not supported to proceed to step 205; if it is not within the network service range, exit the process;

[0069] Step 204, the satellite sends the unique broadcast information generated by combining the user identity and the encryption strategy and the spread spectrum code used when logging out to the user; the user decrypts, receives and uses the broadcast information according to the encryption strategy;

[0070] Step 205, judging the relative angle between satellite and user, looking up table, adjusting information rate according to EIRP change caused by angle change, and completing part channel closing of phased array transmitting antenna;

[0071] Step 206, after user calculates that he will leave coverage area or has no need to continue receiving broadcast according to received satellite ephemeris and his own position, he reports state combining off-network spread spectrum code word; after satellite receives off-network information, it adjusts coverage area.

[0072] Key user broadcast

[0073] For key user broadcast, after ground station sends switching relay mode instruction, satellite's phased array transmitting antenna works in full array mode, and no channel on-off operation of phased array transmitting antenna is performed. When key user needs to receive broadcast information, he sends his own position, identification, capability, periodic demand and other information to satellite. After satellite confirms correct reception of user information and judges that user is in service range, it calculates link rate according to user terminal's position and capability, calculates broadcast information residence period combining broadcast information size, then calculates whether the user is supported by agile coverage area according to user position, satellite position and beam width. If supported, it generates unique broadcast access confirmation information and off-network signal spread spectrum code combining user identification and encryption strategy, and adjusts minimum residence period Tn of the beam, so that user can normally receive information. If not supported, a new beam position is generated, and satellite's back-scan period is increased accordingly.

[0074] Ground station sends instruction, switching relay mode instruction, and phased array works in full array mode.

[0075] Step 301, when user needs to receive broadcast information, he sends his own information to satellite;

[0076] Step 302, after satellite receives, it confirms correct reception of user information, and judges whether the user is in network service range;

[0077] Step 303, if in network service range, satellite calculates link rate according to user terminal's position and reception capability, calculates broadcast information residence period according to broadcast information size, and proceeds to next step; if not in network service range, it exits the process;

[0078] Step 304, satellite first calculates whether the current agile coverage area supports new user according to user position, satellite position and beam width; if the current coverage area supports new user, it proceeds to step 305; if the current coverage area does not support new user, it proceeds to step 306;

[0079] Step 305, the satellite sends the unique broadcast information combined with the user identification and encryption policy and the spreading code word used when logging off to the user, and adjusts the dwell period Tn of the beam, the user receives and uses the broadcast information;

[0080] Step 306, a new wave position is generated to serve the new user, and the unique broadcast information combined with the user identification and encryption policy and the spreading code word used when logging off is sent to the user; the number of wave positions changes from m to m+1 (m is the maximum ratio of the satellite coverage range to the beam width), the flyback period of the beam changes from T0+T1+T2+… …+T m , to T0+T1+T2+… …+T m +T m+1 ; wherein T1, T2, T m represent the dwell periods of the first, second, and mth wave positions respectively.

[0081] Step 307, after the user calculates that it is about to leave the coverage area or does not need to continue receiving the broadcast according to the received satellite ephemeris, its own position, etc., it reports the state combined with the logging-off spreading code word; after the satellite receives it, the coverage area is adjusted.

Claims

1. A satellite communication system with multi-mode capability, characterized in that, Includes a signal processing module, a frequency conversion processing module, a wide-beam receiving antenna, and a phased array transmitting antenna; The signal processing module includes a payload control unit and a baseband processing unit. The payload control unit is responsible for receiving telemetry and control commands from the ground and calculating the beam coverage and beam pointing based on the ephemeris and attitude data broadcast by the satellite platform and the user positions reported by the baseband processing unit. It also controls the downlink transmission rate of the baseband processing unit and the operating mode and beam pointing of the phased array transmitting antenna. The payload control unit switches the phased array transmitting antenna channels based on the coverage area or telemetry and control link margin. While meeting existing communication requirements, the payload control unit adjusts the power or beam of the phased array transmitting antenna. The baseband processing unit... The unit is used to complete uplink and downlink signal processing. Uplink signals support high, medium, and low carrier signal processing to complete the parsing of ground station telemetry and control commands, user network entry information processing, and user network exit information processing, respectively. Among them, the low-frequency carrier signal adopts a spread spectrum processing method, and different network entry users complete the reporting of network exit information through different spread spectrum codes to avoid information conflicts. The telemetry and control commands carried by the high-frequency carrier signal control the opening and closing of the medium and low carrier signal processing functions. Downlink signal processing supports flexible switching of multiple modes through uplink telemetry and control commands, including beacon mode, telemetry data transmission mode, and information broadcast mode. The frequency conversion processing module includes an up-conversion channel and a down-conversion channel; the up-conversion channel is used to perform up-conversion processing on the signal transmitted by the signal processing module and send it to the phased array transmitting antenna; the down-conversion channel receives the signal through a wide-beam receiving antenna, and after amplification and down-conversion, sends it to the baseband processing unit. The wide-beam receiving antenna is an omnidirectional antenna that receives wireless signals and transmits them to the down-conversion channel of the frequency conversion processing module. The phased array transmitting antenna is a phased array antenna, composed of multiple independent channels; the phased array transmitting antenna receives signals from the frequency conversion channel on the frequency conversion processing module and outputs them wirelessly. The payload control unit receives the received level and signal-to-noise ratio margin from the ground station via telemetry and control commands, and adjusts the EIRP of the phased array antenna according to the margin and coverage area.

2. A satellite communication system with multi-mode capability according to claim 1, characterized in that, In the information broadcast mode, the downlink signal processing of the baseband processing unit will send the unique broadcast information generated by combining the user identifier and encryption strategy, as well as the spreading code used when joining and leaving the network, to the user.

3. A satellite communication system with multi-mode capability according to claim 1, characterized in that, The phased array transmitting antenna has some channels powered on by default for beacon transmission over a large coverage area, assisting in high-dynamic user acquisition or stable tracking and adjustment of large-aperture antennas. The beamwidth and EIRP can be adjusted by switching the channels on and off.

4. A communication method based on a satellite communication system, implemented using a multi-mode satellite communication system as described in any one of claims 1 to 3, characterized in that, Both satellite launch and reception are powered on by default. Reception uses a wide-beam receiving antenna to receive commands, while launch uses a phased array transmitting antenna for beacon transmission, telemetry dissemination, or information broadcasting. The telemetry and control function mode and information broadcasting mode are switched via commands. The execution of the measurement and control function mode includes the following process: Step 101: The ground station points to the satellite in advance according to the satellite ephemeris, and makes fine adjustments to the pointing according to the beacon transmission signal to ensure that the satellite and ground antennas are aligned. Step 102: After the pointing adjustment is completed, the ground station will upload its geographical location and receiving capabilities, information, and send a working mode switching command. Step 103: After receiving the command information from the ground station through the wide-beam receiving antenna, the satellite opens all channels of the phased array transmitting antenna and the transmitting power reaches the maximum. Step 104: The payload control unit in the signal processing module calculates the angle based on the ground station location and the satellite's own position and attitude to achieve staring at the ground station. Step 105: The baseband processing unit in the signal processing module switches to the telemetry fast downlink working mode and selects an appropriate downlink rate according to the ground station's receiving capability. Step 106: Satellite telemetry is rapidly transmitted down, and the ground station acquires the satellite's telemetry data. During the transmission process, the ground station uploads the information on the received level and signal-to-noise ratio margin through telemetry and control commands. The payload control unit adjusts the EIRP of the phased array according to the margin, thereby reducing the overall power consumption of the satellite while ensuring the transmission rate. The information broadcasting mode includes broadcasting to ordinary users and broadcasting to key users; The execution of the ordinary user broadcast includes the following process: Step 201: When a user needs to receive broadcast information, they send their own information to the satellite; different users use a contention-based access method. Step 202: After receiving the data, the satellite confirms that the user's personal information has been correctly received and determines whether the user is within the network service range. Step 203: If within the network service range, confirm whether the current transmission coverage area supports adding new users. If it supports adding new users, proceed to step 204; otherwise, proceed to step 205. If you are outside the network service area, exit the process; Step 204: The satellite will send a unique broadcast message generated by combining the user identifier and encryption strategy with the spreading codeword used when decommissioning the network to the user; Users decrypt, receive, and use broadcast messages according to encryption policies; Step 205: Determine the relative angle between the satellite and the user, look up the table, adjust the information rate according to the EIRP change caused by the angle change, and complete the shutdown of some channels of the phased array transmitting antenna. Step 206: After the user calculates whether they are about to leave the coverage area or no longer need to receive broadcasts based on the received satellite ephemeris and their own location, they report the status in conjunction with the network withdrawal spread spectrum code; after the satellite receives the network withdrawal information, it adjusts the coverage area. The execution of the key user broadcast includes the following process: Step 301: When a user needs to receive broadcast information, they send their own information to the satellite; Step 302: After receiving the information, the satellite confirms that the user information has been correctly received and determines whether the user is within the network service range. Step 303: If within the network service range, the satellite calculates the link rate based on the user terminal's location and receiving capability, calculates the broadcast information dwell period based on the broadcast information size, and proceeds to the next step. If you are outside the network service area, exit the process; Step 304: The satellite first calculates whether the current agile coverage area supports adding new users based on the user's location, the satellite's location, and the beamwidth; If the current coverage area supports adding new users, proceed to step 305; if the current coverage area does not support adding new users, proceed to step 306. Step 305: The satellite will send the unique broadcast information generated by combining the user identifier and encryption strategy with the spreading codeword used when leaving the network to the user, and adjust the dwell period Tn of the beam. The user receives and uses the broadcast information. Step 306: A new coverage beam is generated to serve the new user, and a unique broadcast message combining the user's identifier and encryption strategy, along with the spreading codeword used during network decommissioning, is sent to the user; the number of beams changes from m to m+1, where m is at most the ratio of satellite coverage area to beamwidth, and the beam retracement period changes from T0 + T1 + T2 + ... + T m It becomes T0 + T1 + T2 + ... + T m +T m+1 ;where T1, T2, T m These represent the dwell periods of the first, second, and m-th wavelengths, respectively. Step 307: The user calculates whether they are about to leave the coverage area or no longer need to receive broadcasts based on the received satellite ephemeris and their own location, and then reports the status in conjunction with the network withdrawal spread spectrum code; after the satellite receives the report, it adjusts the coverage area.

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