New compress sampling algorithm for GPS signal acquisition in frequency domain

Due to the large and expensive FFT/IFFT core used in the receiver, the cost of realizing the traditional FFT-based fast GPS signal acquisition method is very high. Although some kinds of averaging correlation algorithm can reduce the instant processing points of FFT/IFFT, their noise performance is not promising. This paper proposed a new compress sampling algorithm with high noise immunity for GPS L1 signal acquisition in frequency domain, which allows a smaller and cheaper FFT/IFFT core for fast acquisition unit, and enhances the signal-to-noise ratio (SNR) due to its "redundancy" structure. Simulation results testify the efficiency of this algorithm: the computational complexity has been efficiently suppressed to only 0.93% of the one resulting from the 2D search method in time domain. At the same time the ratio of the maximal to the second maximal correlation value is improved 8.74% over the DFT algorithm that employs no compression and processes the IF (intermediate frequency) sampled signal directly. That means the probability of false alarm is reduced.