Research And Implement Of Real Time Software GPS Receiver

In this paper software based GPS receiver technology has been researched and a real time software GPS receiver was realized. The research focused on real time baseband signal processing algorithms and navigation solution was realized under condition of PC and real-time satellite signals. The correlator was also implemented in hardware, which make the software receiver more flexible and easily modifiable.The major part of this paper was concentrated on expatiation of the major algorithms of baseband signal processing and navigation calculation in software GPS receiver. The acquisition of GPS signal individually employs time domain serial search and frequency domain parallel search by FFT algorithm. Analysis result shows that frequency domain acquisition by FFT algorithm has a much less computation load. Non-correlated DLL and PLL are used in the GPS signal tracking. Navigation messages and pseudoranges were successfully acquired from the base band processing results, thus receiver position, velocity and time were calculated.Finally, the whole system was analyzed,main function units and general flow chart of navigation solution were given.