Reseach On Technology Of Timing Synchronization In Anti-interference Satellite Communication Systems

Satellite communications is an important means to ensure the military's large-scale,long-range mobile operations command information transmission.With the continuous improvement of the status of satellite communication systems in information-based warfare,the types of interference they face are increasing and more complex.The protected anti-jamming satellite communication system has become an important development direction of satellite communications.The protected communication system utilizes various anti-jamming and security enhancement methods to avoid or reduce the degradation,interruption,and intrusion of communication signals caused by the enemy or the environment.Modern anti-jamming satellite communication systems mostly adopt high-speed frequency hopping channel anti-jamming systems,and combine protected technologies such as on-board processing and on-board multi-beam switching routing to achieve protected satellite communications.The timing synchronization technology is one of the key technologies of the anti-jamming satellite communication system,and it is the basis for realizing the satellite-ground/inter-satellite frequency hopping synchronization,network communication and service transmission.This thesis analyzes the research scheme of the timing synchronization technology of anti-interference satellite communication systems on the satellite.According to the technical characteristics of the anti-jamming satellite communication system,the overall architecture,algorithm and flow of the system's synchronous control technology are proposed,and the typical system is calculated,simulated and verified to obtain the main parameters of the timing synchronization technology.The main research results are as follows:(1)The background technology related to timing synchronization is studied to analyze the technical features of the same type of systems in foreign countries.The system architecture and technical parameters related to the synchronous control of the anti-jamming satellite communication system on the satellite were proposed,and the technical requirements for the timing synchronization function of the system were analyzed and given.(2)According to the basic requirements and interdependence of the system's timing synchronization technology,the timing synchronization characteristics of the system are studied,and a timing synchronization system based on time information(TOD)is proposed.Synchronous reference,downlink timing acquisition,uplink ranging synchronization,frame synchronization,inter-satellite link synchronization and other technical solutions are designed,and the impact of timing synchronization scheme on system time synchronization and application system timing is analyzed.(3)In this thesis,two key technical solutions of frequency hopping synchronization and timing synchronization are proposed.The design procedure of frequency hopping synchronization and various parameters required are designed.The key parameters involved in the solution are calculated and given.The symbol synchronization model under the parameter agility frame structure was established,and the influence of high dynamics and the parameter index of symbol timing were simulated and analyzed.(4)A verification system for timing synchronization technology is designed and implemented.Based on a verification system composed of a satellite simulator and a ground terminal,a timing synchronization control software architecture,flow,and main module design scheme are proposed.Software code was written to implement timing synchronization and test validation.