Faster methods for GPS signal acquisition in frequency domain

GPS signal acquisition is most important process in a GPS receiver followed by tracking and extraction of navigation bits. Frequency-domain acquisition methods using FFT are generally employed in a software GPS receiver. This paper exploits the symmetry of the power spectrum of the C/A code, thus reducing the number of FFT points used to perform circular correlation. Further reduction in acquisition time has been achieved by investigating the effect of length of the non coherent pre-integration period. Simulation results show that the proposed methods for software GPS receiver are able to perform faster and reliable acquisition. A trade-off study is also done to seek a good balance between the acquisition accuracy and the processing time.