A time service and data broadcasting ground station baseband system

Abstract

This application discloses a ground station baseband system for timing and data broadcasting. The system receives downlink intermediate frequency (IF) signals and local location information via a baseband signal processing module. It analyzes the downlink IF signals to obtain a first timing message, a first broadcast data message, and measurement data, generating a timing signal. Based on the received second timing message and second broadcast data message, it generates an uplink IF signal. A time interval measurement module compares the timing signal with a preset timing reference signal to obtain a timing deviation monitoring value. A monitoring and data processing module analyzes the received first broadcast data message and first timing message to obtain the bit error rate, frame error rate, and frame loss rate, outputting these values. It also acquires the second timing message and second broadcast data message. This application enables simultaneous timing, timing performance monitoring, and data broadcasting services within a single ground station baseband system.

Description

Technical Field

[0001] This application relates to satellite communication technology and satellite timing technology, and in particular to a ground station baseband system for timing and data broadcasting. Background Technology

[0002] Building an integrated space-ground time service system is an important national strategic plan, playing a fundamental supporting role in economic and social development and national defense.

[0003] With the construction of my country's high-precision ground-based time service system, a ground-based time service network is about to be formed. However, there is currently a lack of a ground station baseband system that integrates satellite time service and service performance monitoring, satellite-ground fusion time service information, and time service performance monitoring information broadcasting. Summary of the Invention

[0004] The main objective of this application is to provide a time synchronization and data broadcasting ground station baseband system, which aims to solve the technical problems of time synchronization and data broadcasting ground station baseband systems.

[0005] To achieve the above objectives, this application provides a ground station baseband system for timing and data broadcasting, comprising: a baseband signal processing module and a monitoring and data processing module communicatively connected, and a time interval measurement module communicatively connected to both the baseband signal processing module and the monitoring and data processing module; wherein, the baseband signal processing module is used to receive a baseband downlink intermediate frequency signal and local location information, analyze and process the baseband downlink intermediate frequency signal to obtain a first timing message, a first broadcast data message, and measurement data, generate a timing signal based on the first timing message, the local location information, and the measurement data, and send the first broadcast data message, the first timing message, and the measurement data. The timing signal, and the baseband uplink intermediate frequency signal generated based on the received second timing message and the second broadcast data message, and the baseband uplink intermediate frequency signal transmitted; the time interval measurement module is used to compare the timing signal with a preset timing reference signal, obtain a timing deviation monitoring value, and transmit the timing deviation monitoring value; the monitoring and data processing module is used to parse the received first broadcast data message and the first timing message, obtain the bit error rate, frame error rate and frame loss rate, and output the bit error rate, frame error rate and frame loss rate, and acquire the second timing message and the second broadcast data message, and transmit the second timing message and the second broadcast data message.

[0006] Optionally, the baseband signal processing module further includes: a first processing submodule and a second processing submodule, an AD conversion submodule communicatively connected to the first processing submodule, and a DA conversion submodule communicatively connected to the second processing submodule; wherein, the AD conversion submodule is used to receive the baseband downlink intermediate frequency signal, perform downconversion processing on the baseband downlink intermediate frequency signal to obtain a near-zero frequency digital baseband signal, and output the near-zero frequency digital baseband signal; the first processing submodule is used to acquire and track the received near-zero frequency digital baseband signal to obtain a tracking signal, and sequentially process the tracking signal... The system performs message synchronization, channel decoding, and message extraction processing to obtain the first timing message, the first broadcast data message, and measurement data, and sends the first timing message and the first broadcast data message to the monitoring and data processing module. The second processing submodule performs channel coding, spread spectrum modulation, and intermediate frequency carrier modulation processing on the received second timing message and the second broadcast data message in sequence to obtain an uplink intermediate frequency signal, and sends the uplink intermediate frequency signal to the DA conversion submodule. The DA conversion submodule performs digital-to-analog conversion on the received uplink intermediate frequency signal to obtain the baseband uplink intermediate frequency signal.

[0007] Optionally, the baseband signal processing module further includes: a measurement submodule, communicatively connected to the first processing submodule, the measurement submodule being used to analyze and process the received satellite downlink loopback signal to obtain a measured value of the code and carrier deviation, and to send the measured value of the code and carrier deviation to the virtual clock interface; and a frequency control submodule, communicatively connected to the second processing submodule, the frequency control submodule being used to receive virtual clock information sent by the virtual clock interface, generate frequency control information based on the virtual clock information, modulate the baseband uplink intermediate frequency signal using the frequency control information, and send the modulated baseband uplink intermediate frequency signal.

[0008] Optionally, the system further includes: a filtering and gain control channel module, which is communicatively connected to both the AD conversion submodule and the DA conversion submodule. The filtering and gain control channel module is used to receive the baseband uplink intermediate frequency signal, perform filtering and power control processing on the baseband uplink intermediate frequency signal to obtain a power-controlled baseband uplink intermediate frequency signal, and transmit the power-controlled baseband uplink intermediate frequency signal to the ground station antenna and radio frequency system. It also receives the baseband downlink intermediate frequency signal transmitted through the ground station antenna and radio frequency system, and performs filtering and power control processing on the baseband downlink intermediate frequency signal to obtain the baseband downlink intermediate frequency signal.

[0009] Optionally, the system further includes a frequency synthesizer module, used to provide the preset timing reference signal to the baseband signal processing module.

[0010] Optionally, the baseband signal processing module is further configured to generate device control and status display information based on the operating status. The monitoring and data processing module includes: a host computer monitoring submodule, configured to receive the device control and status display information and send the device control and status display information; and a data processing and storage submodule, configured to perform data storage, bit error comparison, frame error statistics, and frame loss statistics on the received timing deviation monitoring value, the first timing message, the first broadcast data message, and the measurement data to obtain the bit error rate, the frame error rate, and the frame loss rate, and send the bit error rate, the frame error rate, and the frame loss rate.

[0011] Optionally, the monitoring and data processing module further includes: an instruction issuing submodule, used to perform state control on the baseband signal processing module using parameter commands.

[0012] This application proposes a ground station baseband system for timing and data broadcasting. A baseband signal processing module receives downlink intermediate frequency (IF) signals and local location information, analyzes the downlink IF signals to obtain a first timing message, a first broadcast data message, and measurement data. Based on the first timing message, local location information, and measurement data, a timing signal is generated, and the first broadcast data message, the first timing message, and the timing signal are transmitted. Additionally, based on the received second timing message and second broadcast data message, a baseband uplink IF signal is generated and transmitted. The time interval measurement module is used to compare the timing signal with the preset timing reference signal, obtain the timing deviation monitoring value, and send the timing deviation monitoring value; the monitoring and data processing module is used to parse and process the received first broadcast data message and the first timing message to obtain the bit error rate, frame error rate, and frame loss rate, and output the bit error rate, frame error rate, and frame loss rate; and to acquire the second timing message and the second broadcast data message, and send the second timing message and the second broadcast data message. In a single ground station baseband system, it is possible to perform timing, timing performance monitoring and data broadcasting services simultaneously. Attached Figure Description

[0013] Figure 1 This is a hardware structure block diagram provided for an embodiment of the ground station baseband system for timing and data broadcasting in this application;

[0014] Figure 2 A schematic diagram provided for an embodiment of the ground station baseband system for timing and data broadcasting in this application;

[0015] Figure 3 This is an external interface provided for an embodiment of the ground station baseband system for timing and data broadcasting in this application.

[0016] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0018] The purpose of this invention is to provide a ground station baseband system for timing and data broadcasting based on a satellite transponder, which is used to generate, transmit and receive timing and data broadcasting signals, and realize integrated services of timing service, timing performance monitoring service and data broadcasting.

[0019] Reference Figure 1 The timing and data broadcasting ground station baseband system provided in the first embodiment of this application may include: a baseband signal processing module 1 and a monitoring and data processing module 2, which are communicatively connected, and a time difference measurement module 3, which is communicatively connected to both the baseband signal processing module 1 and the monitoring and data processing module 2; wherein, the baseband signal processing module 1 is used to receive the baseband downlink intermediate frequency signal and local location information, analyze and process the baseband downlink intermediate frequency signal to obtain a first timing message, a first broadcast data message and measurement data, generate a timing signal based on the first timing message, local location information and measurement data, and send the first broadcast data. The system includes a time synchronization message, a first time synchronization message, and a time synchronization signal; a baseband uplink intermediate frequency signal is generated based on the received second time synchronization message and the second broadcast data message, and the baseband uplink intermediate frequency signal is sent; a time difference measurement module 3 is used to compare the time synchronization signal with a preset time synchronization reference signal to obtain a time synchronization deviation monitoring value, and send the time synchronization deviation monitoring value; a monitoring and data processing module 2 is used to parse and process the received first broadcast data message and the first time synchronization message to obtain the bit error rate, frame error rate, and frame loss rate, and output the bit error rate, frame error rate, and frame loss rate; and to acquire the second time synchronization message and the second broadcast data message, and send the second time synchronization message and the second broadcast data message.

[0020] The baseband signal processing module 1 simultaneously extracts the time delay measurement value (i.e., measurement data) from the first time synchronization message, demodulates the virtual clock information and ephemeris information obtained from the first time synchronization message, and generates a time synchronization signal based on the time delay measurement value, virtual clock information, and ephemeris information. The time synchronization signal can be a 1PPS time synchronization signal, and the module completes the generation and output of the 1PPS time synchronization signal. The time difference measurement module 3 compares the time synchronization signal with a preset time synchronization reference signal to obtain the time synchronization deviation monitoring value, and sends the time synchronization deviation monitoring value to the monitoring and data processing module 2. Through the above process, the time synchronization and data broadcasting ground station baseband system realizes the generation of time synchronization signals and the detection of time synchronization deviations, and obtains time synchronization performance monitoring information. Finally, the baseband signal processing module 1 sends the time synchronization performance monitoring information to the monitoring and data processing software.

[0021] Furthermore, the monitoring and data processing module 2 is a single-board computer.

[0022] In the embodiments of this application, the baseband signal processing module 1 further includes: a first processing submodule 15 and an AD conversion submodule 13 communicatively connected to the first processing submodule 15, wherein the AD conversion submodule 13 is used to receive the baseband downlink intermediate frequency signal, perform downconversion processing on the baseband downlink intermediate frequency signal to obtain a near-zero frequency digital baseband signal, and output the near-zero frequency digital baseband signal.

[0023] Specifically, the AD conversion submodule 13 can perform AD analog-to-digital conversion on the baseband downlink intermediate frequency signal of the satellite downlink loopback link, the antenna radio frequency loopback signal receiving link, or the satellite downlink timing performance monitoring receiving link to obtain a near-zero frequency digital baseband signal, and send the near-zero frequency digital baseband signal to the first processing submodule.

[0024] The first processing submodule 15 is used to acquire and track the received near-zero frequency digital baseband signal to obtain a tracking signal. The tracking signal is then processed sequentially with message synchronization, channel decoding, and message extraction to obtain a first timing message, a first broadcast data message, and measurement data. The first timing message and the first broadcast data message are then sent to the monitoring and data processing module 2.

[0025] The first processing submodule 15 is a baseband signal receiving and processing module. The baseband signal receiving and processing module can capture and track the near-zero frequency digital baseband signal after down-conversion to obtain a tracking signal. Then, it performs message synchronization, channel decoding, and message extraction on the tracking signal to obtain extracted information. The extracted information is then demodulated to obtain the first timing message and the first broadcast data message, and the first timing message and the first broadcast data message are sent to the monitoring and data processing module 2.

[0026] In embodiments of this application, the baseband signal processing module 1 further includes a second processing submodule 16 and a DA conversion submodule 14 communicatively connected to the second processing submodule 16; wherein, the second processing submodule 16 is used to sequentially perform channel coding, spread spectrum modulation and intermediate frequency carrier modulation processing on the received second timing message and the second broadcast data message to obtain an uplink intermediate frequency signal, and send the uplink intermediate frequency signal to the DA conversion submodule 14; the DA conversion submodule 14 is used to perform digital-to-analog conversion on the received uplink intermediate frequency signal to obtain a baseband uplink intermediate frequency signal.

[0027] For example, the second processing submodule 16 is a baseband signal generation module, which is used to perform LDPC / convolutional code channel coding, spread spectrum BPSK (10) modulation and intermediate frequency 140MHz carrier modulation on the timing message and broadcast data message sent by the monitoring and data processing module 2, respectively, to generate a modulated intermediate frequency signal, and then output the analog 140MHz intermediate frequency signal to the filtering and gain control module 17 through the DA conversion submodule.

[0028] In summary, the baseband signal processing module 1 interacts with the monitoring and data processing module 2 via a network interface. The baseband signal processing module 1 receives the second timing message and the second broadcast data message from the monitoring and data processing module 2. After encoding, spreading modulation, and intermediate frequency modulation of the second timing message and the second broadcast data message, it outputs an intermediate frequency digital signal. This intermediate frequency digital signal undergoes DA conversion, filtering, and gain control to obtain the baseband uplink intermediate frequency signal, which is then output to the upconverter at the ground station. The satellite ground station receives the baseband downlink intermediate frequency signal and outputs a downconverted downlink intermediate frequency signal. This downlink intermediate frequency signal undergoes filtering, gain control, and DA conversion before entering the baseband signal processing module 1 for signal acquisition, tracking, decoding, and other processing to obtain the first timing message and the first broadcast data message. The module then reports the message information to the monitoring and data processing module 2. The baseband signal processing module 1 extracts the ephemeris and virtual clock information from the first timing message, and completes the timing function based on the obtained time delay measurement value and local location information, outputting a 1PPS timing signal. At the same time, it uses the time difference measurement module 3 to measure the deviation information between the 1PPS timing signal and the reference 1PPS, and sends the timing deviation monitoring information to the monitoring and data processing software.

[0029] Furthermore, the function of the baseband signal processing module 1 in receiving the satellite downlink and generating a 1PPS timing signal can be independent of other signal processing functions. The clock reference signal used in this timing signal is from a different source than the clock reference signal of the signal generation and processing function.

[0030] In the embodiments of this application, the baseband signal processing module 1 further includes a measurement submodule 11 and a frequency control submodule 12. The measurement submodule 11 is communicatively connected to the first processing submodule 15. The measurement submodule 11 is used to analyze and process the received satellite downlink loopback signal to obtain the measured value of the code and carrier deviation, and send the measured value of the code and carrier deviation to the virtual clock interface. The frequency control submodule 12 is communicatively connected to the second processing submodule 16. The frequency control module is used to receive virtual clock information sent by the virtual clock interface, generate frequency control information based on the virtual clock information, modulate the baseband uplink intermediate frequency signal using the frequency control information, and send the modulated baseband uplink intermediate frequency signal.

[0031] The baseband signal processing module 1 receives the transmission frequency adjustment from the virtual clock software interface, combines it with its own code and carrier deviation measurement values ​​to make a comprehensive judgment, completes the transmission frequency control, and sends the code and carrier deviation measurement values ​​to the virtual clock interface. The frequency control submodule 12 is communicatively connected to the second processing submodule 16. The frequency control submodule 12 is used to receive virtual clock information sent by the virtual clock interface, generate frequency control information based on the virtual clock information, modulate the baseband uplink intermediate frequency signal using the frequency control information, and send the modulated baseband uplink intermediate frequency signal, thereby realizing the frequency modulation of the baseband uplink intermediate frequency signal to obtain the final baseband uplink intermediate frequency signal.

[0032] In the embodiments of this application, the system further includes a filtering and gain control module 17. The filtering and gain control module 17 is communicatively connected to the AD conversion submodule 13 and the DA conversion submodule 14. The filtering and gain control module 17 is used to receive the baseband uplink intermediate frequency signal, perform filtering and power control processing on the baseband uplink intermediate frequency signal to obtain the power-controlled baseband uplink intermediate frequency signal, and send the power-controlled baseband uplink intermediate frequency signal to the ground station antenna and radio frequency system. It also receives the baseband downlink intermediate frequency signal sent through the ground station antenna and radio frequency system, and performs filtering and power control processing on the baseband downlink intermediate frequency signal to obtain the power-controlled baseband downlink intermediate frequency signal.

[0033] For example, the filtering and gain control module 17 is used to filter and control the power of the analog intermediate frequency (IF) signal generated by the baseband signal processing module 1, and send the output 140MHz IF signal to the ground station antenna and radio frequency system for transmission. In the satellite downlink loopback link, the antenna radio frequency loopback signal receiving link, and the satellite downlink timing performance monitoring receiving link, the filtering and gain control module 17 filters and controls the power of the IF signal output by the ground station antenna and radio frequency system, and sends the 140MHz IF analog signal to the baseband signal processing module 1 for processing.

[0034] In embodiments of this application, the system further includes a frequency synthesizer module 20, which provides a preset timing reference signal to the baseband signal processing module 1. Specifically, the frequency synthesizer module 20 is used to generate and distribute the operating clocks of each module in the ground station baseband system, providing each module of the baseband system with an external timing reference signal or an operating clock from an onboard high-stability crystal oscillator.

[0035] Furthermore, the frequency synthesizer module 20 uses an external reference clock or an internal high-stability crystal oscillator as its clock source.

[0036] In the embodiments of this application, the baseband signal processing module 1 is further used to generate device control and status display information based on the operating status. The monitoring and data processing module 2 includes a host computer monitoring submodule 21 and a monitoring and data processing module 2. The host computer monitoring submodule 21 is used to receive and send the device control and status display information. The monitoring and data processing module 2 is used to perform data storage, bit error comparison, frame error statistics, and frame loss statistics on the received timing deviation monitoring value, the first timing message, the first broadcast data message, and the measurement data to obtain the bit error rate, frame error rate, and frame loss rate, and then send the bit error rate, frame error rate, and frame loss rate.

[0037] In the embodiments of this application, the monitoring and data processing module 2 further includes an instruction issuing submodule, which is used to perform state control on the baseband signal processing module using parameter commands.

[0038] Specifically, the monitoring and data processing module 2 is the interface for local human-machine interaction. The demodulated first timing message, first broadcast data message, and measurement data are transmitted from the baseband signal processing module 1 to the monitoring and data processing module 2. The monitoring and data processing module 2 performs operations such as data storage, error comparison, frame error statistics, frame loss statistics, and data display on the first timing message, first broadcast data message, and measurement data. The baseband signal processing module 1 packages the device control and status display information and timing performance monitoring information and actively reports them to the host computer monitoring submodule 21 of the monitoring and data processing module 2. The host computer monitoring submodule 21 receives the device control and status display information and sends the device control and status display information and timing performance monitoring information to the data management software.

[0039] Reference Figure 3The working principle of the time synchronization and data broadcasting ground station baseband system (hereinafter referred to as the ground station baseband system) 100 is as follows: The ground station baseband system 100 receives broadcast messages from the performance analysis and monitoring subsystem 700, as well as ephemeris and virtual clock data from the orbit determination data center 200 and the virtual clock software 300. It then uses the message arrangement software 400 to arrange the data format, modulates it to an intermediate frequency (IF) signal, and outputs it to the upconverter of the satellite ground station 500. The ground station baseband system 100 receives the downlink IF signal output from the downconverter of the satellite ground station 500, and completes the acquisition, tracking, and message demodulation processing of the IF signal, calculating the bit error rate, frame error rate, and frame loss rate of the satellite-based broadcast messages. The ground station baseband system 100 performs time delay measurement through the satellite loopback link and sends the time delay measurement results to the virtual clock software 300. It then combines the frequency adjustment amount generated by the virtual clock software 300 with the equipment's own time delay measurement value to control the transmission frequency. The ground station baseband system 100 receives downlink intermediate frequency signals, performs time synchronization functions such as extracting satellite-to-ground time delay measurements, correcting ephemeris and virtual clock delays, and correcting propagation atmospheric errors, and outputs a 1PPS time synchronization signal. Simultaneously, it measures the time difference between the 1PPS time synchronization signal and a reference 1PPS signal. The ground station baseband system 100 outputs performance monitoring information such as time synchronization deviation monitoring values, bit error rate, frame error rate, and frame loss rate to the data management software 600.

[0040] Continue to refer to Figure 3 The ground station's time and frequency equipment traces to an external time and frequency subsystem, providing a 1pps pulse signal and a 10MHz frequency signal to the ground station baseband system 100. The data management software 600 sends the timing performance monitoring information output from the ground station baseband system 100 to the performance analysis and monitoring subsystem 700, providing an interface service to the outside world.

[0041] Specifically, refer to Figure 2 , Figure 3 The ground station baseband system 100 for timing and data broadcasting can complete the generation of timing signals, detection of timing deviations, and data transmission and reception functions through the following steps.

[0042] Step 1: Following the preset workflow, control commands carrying parameters are issued through the monitoring and data processing module 2;

[0043] Step 2: Timing and Data Broadcasting. The ground station baseband system 100 sets its status according to the control command and receives the baseband downlink intermediate frequency signal from the ground station antenna and radio frequency system through the filtering and gain control module 17.

[0044] Step 3: The message arrangement software 400 outputs the uplink message to the monitoring and data processing module 2. After the uplink signal encoding and modulation functions are completed on the baseband signal processing module 1, the baseband uplink intermediate frequency signal is output to the ground station antenna and radio frequency system and transmitted through the antenna.

[0045] Step four: The baseband signal processing module 1 completes the acquisition, despreading, demodulation, bit synchronization, frame synchronization, and decoding of the downlink intermediate frequency signal; the downlink message obtained by demodulation is output to the message arrangement software 400 through the monitoring and data processing module 2, and is stored and statistically analyzed locally.

[0046] Step 5: The baseband signal processing module 1 simultaneously extracts the measured values ​​of code and carrier deviation, sends them to the virtual clock software 300, and stores them locally.

[0047] Step six: The baseband signal processing module 1 also generates and outputs the 1PPS timing signal, and the time difference measurement module 3 performs time difference measurement to monitor the timing performance.

[0048] Step 7: The virtual clock software 300 outputs adjustment data such as time delay and frequency. The baseband signal processing module 1 processes the uplink message in real time, adjusts the transmission signal frequency, outputs the baseband uplink intermediate frequency signal, and then transmits the baseband uplink intermediate frequency signal through the ground station antenna and the radio frequency system.

[0049] Step 8: The baseband signal processing module 1 reports the device parameters and status to the data management software 600 in real time and monitors the task progress.

[0050] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A ground station baseband system for time synchronization and data broadcasting, characterized in that, include: The baseband signal processing module and the monitoring and data processing module are connected in communication, and the time difference measurement module is also connected in communication with both the baseband signal processing module and the monitoring and data processing module; The baseband signal processing module is configured to receive a baseband downlink intermediate frequency signal and local location information, analyze and process the baseband downlink intermediate frequency signal to obtain a first timing message, a first broadcast data message and measurement data, generate a timing signal based on the first timing message, the local location information and the measurement data, send the first broadcast data message, the first timing message and the timing signal, and generate a baseband uplink intermediate frequency signal based on the received second timing message and the second broadcast data message, and send the baseband uplink intermediate frequency signal. The time difference measurement module is used to compare the time synchronization signal with the preset time synchronization reference signal to obtain the time synchronization deviation monitoring value, and send the time synchronization deviation monitoring value. The monitoring and data processing module is used to parse and process the received first broadcast data message and first timing message to obtain the bit error rate, frame error rate and frame loss rate, and output the bit error rate, frame error rate and frame loss rate; and to obtain the second timing message and the second broadcast data message, and send the second timing message and the second broadcast data message. The baseband signal processing module further includes: The measurement submodule is communicatively connected to the first processing submodule. The measurement submodule is used to analyze and process the received satellite downlink loopback signal to obtain the measured value of the code and carrier deviation, and send the measured value of the code and carrier deviation to the virtual clock interface. A frequency control submodule is communicatively connected to the second processing submodule. The frequency control submodule is used to receive virtual clock information sent by the virtual clock interface, generate frequency control information based on the virtual clock information, modulate the baseband uplink intermediate frequency signal using the frequency control information, and send the modulated baseband uplink intermediate frequency signal. The baseband signal processing module is also used to generate equipment control and status display information based on operating conditions, and the monitoring and data processing module further includes: The host computer monitoring submodule is used to receive the device control and status display information and send the device control and status display information. The data processing and storage submodule is used to perform data storage, bit error comparison, frame error statistics, and frame loss statistics on the received timing deviation monitoring value, the first timing message, and the first broadcast data message to obtain the bit error rate, the frame error rate, and the frame loss rate, and to send the bit error rate, the frame error rate, and the frame loss rate.

2. The time synchronization and data broadcasting ground station baseband system as described in claim 1, characterized in that, The baseband signal processing module includes: a first processing submodule and an AD conversion submodule communicatively connected to the first processing submodule; The AD conversion submodule is used to receive the baseband downlink intermediate frequency signal, perform downconversion processing on the baseband downlink intermediate frequency signal to obtain a near-zero frequency digital baseband signal, and output the near-zero frequency digital baseband signal. The first processing submodule is used to acquire and track the received near-zero frequency digital baseband signal to obtain a tracking signal. The tracking signal is then processed sequentially with message synchronization, channel decoding, and message extraction to obtain the first timing message, the first broadcast data message, and the measurement data. The first timing message and the first broadcast data message are then sent to the monitoring and data processing module.

3. The time synchronization and data broadcasting ground station baseband system as described in claim 2, characterized in that, The baseband signal processing module further includes: a second processing submodule and a DA conversion submodule communicatively connected to the second processing submodule; The second processing submodule is used to sequentially perform channel coding, spread spectrum modulation and intermediate frequency carrier modulation on the received second timing message and the second broadcast data message to obtain an uplink intermediate frequency signal, and send the uplink intermediate frequency signal to the DA conversion submodule. The DA conversion submodule is used to perform digital-to-analog conversion on the received uplink intermediate frequency signal to obtain the baseband uplink intermediate frequency signal.

4. The time synchronization and data broadcasting ground station baseband system as described in claim 3, characterized in that, The system also includes: The filtering and gain control channel module is communicatively connected to both the AD conversion submodule and the DA conversion submodule. This module receives the baseband uplink intermediate frequency (IF) signal, performs filtering and power control processing on it to obtain a power-controlled baseband uplink IF signal, and transmits this power-controlled signal to the ground station antenna and radio frequency system. It also receives the baseband downlink IF signal transmitted through the ground station antenna and radio frequency system, performs filtering and power control processing on it to obtain a power-controlled baseband downlink IF signal.

5. The time synchronization and data broadcasting ground station baseband system as described in claim 1, characterized in that, The system also includes: The frequency synthesizer module is used to provide the preset timing reference signal to the baseband signal processing module.

6. The time synchronization and data broadcasting ground station baseband system as described in claim 1, characterized in that, The monitoring and data processing module also includes: The instruction issuing submodule is used to perform state control on the baseband signal processing module using parameter commands.

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