New Compress Sampling Algorithm for FFT-based GPS Signal Acquisition

Presently FFT usage in GPS receivers has been a topic of extensive study and many improved FFT-based acquisition methods with averaging correlation technique also have emerged. Although averaging arithmetic can reduce the instant processing points of FFT/IFFT, their noise performance is not promising. In this paper a novel compress-sampling algorithm for FFT-base GPS signal acquisition method is proposed. It not only diminishes the size of FFT/IFFT core but also enhances the noise immunity of receiver with its "redundancy" structure. Simulation results of Matlab testify that the computational complexity of the novel algorithm has been efficiently suppressed to only 0.93% over the 2D search method in time domain. At the same time the lower amplitude threshold obtained from the novel method gets a lower false alarm probability comparing with the direct DFT algorithm with no compression. The noise immunity is enhanced.