Research And Design On The Swift Synchronization Of PN Code In Compass Receiver In High Dynamic Station

Compass Positioning System is researched and developed by our country. The system provides swift location, real-time navigation, simple communication as well as precise time service, and takes a great important role in the field of development of national defense and civil navigation and orientation. This system is a system based on direct sequence spread spectrum (DSSS) technique. In DSSS system, if the synchronization of Pseudo Noise Code is very bad, exact information do not received. So, it affects the performance of the whole system, because this technology is not only the precondition of working well, but also the key of precise positioning. Research and implement synchronization of the Pseudo Noise Code of Compass is of great significance to improve the positioning precision and the user terminal's performance index.This paper is finished in the process of research and development of Compass receiver. First of all, This paper introduced the spread spectrum, and especially do research of DSSS. Then the composition, trait, function, the principle of working and signal structure of Compass is analyzed. It deeply researches the theory of the Pseudo Noise Code's synchronization and compares and analyzes the algorithmic of Code's synchronization. In terms of the signal trait and the style of modulation and the protocol of navigation information the algorithmic of synchronization of PN code is put forward which Code acquisition uses the principle of sliding correction method and code tracking uses advance-delay tracking method.The paper proposed the design scheme of base band module adopt bulky resources of FPGA. After the design, compilation, fit and download of synchronization's module, module is debugged and tested. The test result indicates that the design project can satisfy the system's design wants and proves the validity and feasibility of the project.