Research And Implementation Of Baseband Signal Processing Algorithm For GPS Software Receiver Based On FPGA

Software-defined receiver is being paid more attention because of its flexibility. Baseband signal processing algorithm is the core of the software receiver, the precondition of the navigation solution, and can affecting the entire receiver performance. The researching of baseband signal processing algorithm for GPS will also provide theoretical support and practical experience for the researching of other satellite navigation systems.The paper introduces the structure properties and production processes of the GPS signal. The paper mainly discuss the baseband signal processing algorithm, and describe how the baseband get the navigation data and measurements from the GPS signal.The paper designs two kinds of acquisition circuit, time domain serial search and frequency domain parallel search by FFT algorithm. The paper simulates the processing of acquisition by Matlab, and analyzes their performance deeply.The tracking loop is designed by using frequency locked loop-assisted Costas loop and delay-locked loop. Based on the analyzing the principle of each crucial component in the loop, the algorithm is designed. Then the whole tracking loop is simulated by Matlab. The method of setting the parameters of the loop is also discussed.At last, the baseband signal processing component is realized in FPGA. And the whole GPS software receiver is simulated by Matlab, to assist the debugging of the receiver. The navigation data is transported to computer by serial port, for proving the correctness of the baseband signal processing algorithm...