Study Of The Performance Improvements About The System Of Low-profile Vehicle-borne "Mobile Communication"

With the rapid development of satellite communication technology, satellite communication business is getting more and more broader, and its application is growing wider. Now, a large number of fixed stations and portable stations are widely used, but fixed satellite communication system will be unable to meet the requirements. Then mobile satellite communication system came into being. This thesis introduces the improvements of the vehicle-borne "mobile communication" earth station system's performance, including the improvement of the mechanical structure, hardware circuitry and software algorithms.This thesis describes a low-profile vehicle-borne "mobile communication" system's composition principle and the ways of working, analyzes the impact on the system from the antenna mechanical structure, the hardware architecture and software algorithms to get the improvements of system. Firstly, it describes the existing pitch transmission structure and analyzes this structure's impact on system, then proposes the improvements to enhance the performance of the pitch drive. Secondly, it introduces the system's hardware circuit, and gives the improvements about the parts of circuit which often cause a system failure. Finally, through analysis of system's control software, we obtained some filtering methods, PID algorithm, improvements of circular cone scans performance and the drift compensation algorithm of angular rate sensor to improve the system's performance. The system's performance has improved significantly after the improvements.Currently, the system improvement has been basically completed. The antenna can connect to the satellite exactly, and also can maintain the quality of communication, even on the three-dimensional motion simulator. Now ,the system is going through the final test and improvement, and expected to be delivered soon.