Tracking And Message Processing Technology Research And Implementation For Multi-system Satellite Navigation Signals

The global satellite navigation system, as an important infrastructure in the field of national spatial and temporal reference, is the guarantee of national security and daily life. With the comprehensive construction of the navigation system, originally not abundant spectrum resources of navigation signal become more and more crowded. In order to solve this problem and improve the accuracy of positioning, enhance the ability to resist interference, reduce the bit error rate, a variety of new signals are proposed. The new signals have a great change in the message, spread spectrum code and modulation mode. Therefore, it is important to study the tracking loop and message processing technology of the new signals and the old signals.This paper begins with the introduction of the new signal system and the traditional signal system, and studies the tracking technology and message processing method of new system and the traditional system signals. Based on the platform of DSP and FPGA, the design of each module is designed, and the test environment is built to test the performance of each module.The main research work of this paper is summarized as follows:(1) The development status of satellite navigation system in the world and the research status of LDPC decoding technology are analyzed;(2) The differences between the new system and the traditional signals are analyzed from the message, spread spectrum and modulation mode;(3) According to the complexity, hardware conditions and tracking performance, the tracking methods of BPSK signals and BOC signals are studied. According to the characteristics of each frequency point, the compatible tracking loop is designed. The design of related channels in FPGA and loop control channels in Niosâ…¡are completed.(4) The bit structure, frame structure, interleaving mode and encoding mode of each frequency point signals are studied, and the design of the bit synchronization, frame synchronization, de-interleaving and decoding modules is completed;(5) The design of the receiver is introduced, and the function and performance of the tracking and message processing modules are verified.