Three System Navigation Receiver Information Processing Technology Research

With the rapid development of the Global Navigation Satellite System, compatible with multiple navigation system (USA’s GPS, Russian’s GLONASS, European’s Galileo and China’s BDS (BeiDou System), etc) of the multi-system navigation receiver will become the important research direction in the future. Compared with the single-system navigation receiver, multi-system navigation receiver has a series of advantages, such as more satellites, good coverage, and high precision, good reliability and so on. This subject is amied at researching on a miniaturized, with high dynamic performance and can be compatible with GPS/L1, GLONASS/L1and BDS/B1three frequency points navigation receiver board.According to the principle of satellite navigation and positioning and the problems encountered in the actual development, the basic principles of the three-system navigation receiver and algorithms is studied in detail in this paper. Receiver based on DSP and FPGA architecture, FPGA completes the base-band signal acquisition and tracking, DSP completes the control on the base-band module and the PVT (Positioning Velocity and Timing) solution. Firstly, the article studies the BDS/B1frequency navigation receiver implementation, and then develops the three-system receiver on the basis of the original Dual-model receiver. Considering that the receiver need to deal with the three systems of satellite information, and need to meet36channels, lOHz positioning frequency, so reducing the FPGA resource utilization and improving the efficiency of DSP computation is a key point in the research of this paper. Reduce the resource usage of FPGA by using fast acquisition multiplexing module and frame synchronization multiplexing module; by reducing the DSP interrupt service subroutine, positioning satellites choosing and satellite orbit interpolation method are used to reduce the DSP computation overhead. Finally, several aspects of the PVT solution of the key technologies are analyzed, such as α-β-γ filter, three system of coordinate system conversion, carrier phase smoothing and the receiver weighted autonomous integrity monitoring (RAIM) and so on.