A novel fast acquisition algorithm for GPS C/A signals

In a GPS system, the process of acquisition costs most time of the whole, which is due to the large number of required operations in the correlator. Common methods usually use FFT or PFA(Prime Factor Algorithm) to calculate the correlation, choosing float as the data type of the operation, which will obviously increase computational complexity. In consideration of the specific storage mode of GPS data, we propose a novel algorithm using 2-bit data as the operand in PFA. In this method, GPS data, carrier frequency and twiddle factors of the butterfly calculation will be transformed into bit type, and FFT will be performed only with fixed bit-wise method. Experiments show the significant performance and efficiency improvements of the proposed algorithm, which is one promising solution for fast software GPS receivers.