Satellite Receiver Signal Tracking Technology And Its Implementation

Satellite navigation system is a hotspot of Space Telecommunications. Mordern satellite navigation system provides high precise time information and navigation service for military and became an important part of ocean succor and car navigation for civil.For some special using, the satellite receiver will work in the circumstance of high dynamic and low SNR. In such circumstance, the traditional synchronization method can not work. It is hard to get the satellite signals . So it is important to study how to receive satellite signals in this circumstance.Signal synchronization is the precondition of information getting, it often divide into two steps: acquisition and tracking. This paper sets GPS as the example to do some research on the signal tracking.GPS use The Direct Sequence Spread Spectrum (DSSS) technologies, the signal tracking includs carrier tracking and code tracking. The receiver has to suffer high dynamic and in the mean time it has to keep tracking exactly.This paper will propose a tracking structure in which PLL (Phase locked loop) assists with FLL(frequency locked loop) and carrier tracking loop assists code tracking loop.In view of the multipath interference, the code track system use both of normal correlator and narrow correlator. This can reduce the interference and improve the position precision.The system described in this paper was realized in FPGA, its performance satisfy the design target by validate it in a texting board.