Research On Baseband Signal Processing Technology Of Satellite Navigation Receivers

The development of the satellite navigation system puts forward new requirements for satellite navigation receivers. Research high-performance baseband signal processing algorithm and develop new generation of multiple system compatible receivers has become the trend. This topic is from a key project of NCUT. It aims to develop a high-performance satellite navigation receiver which with GPS, GLONASS and with quickly capture and high dynamic. Baseband signal processing is one of important technology in the research. The research of this subject is based on spread spectrum communication theory, and the object is civil C/A code of GPS and GLONASS, the hardware platform is FPGA and DSP. The purpose of research is to develop efficient acquisition and tracking algorithm, and so as to improve the overall performance of receiver.There are several ways of acquisition. This paper analyzed them and then selected circular correlation that based on Fast Fourier Transform (FFT). This paper analyzed the performance through simulation, realized and verified. Finally, applicated them in real-time receiver and tested through experiments. It is faster than traditional methods by several times. Several tracking algorithms are analyzed in this topic. According to the performance between them the paper determined the second-order FLL assisted the third-order PLL as carrier tracking loop and the DLL as code tracking loop. Then realized all logic modules, verified them with simulation and realized discriminators, loop filter and control procedures. Finally the static and dynamic test results show that the tracking loop can normal work and satisfy the requirement of design.