Fast acquisition method of navigation receiver based on folded PMF-FFT

摘要

To overcome the influence of Doppler shifts for the acquisition time of navigation receiver in high dynamic situation, a improved method adopts an acquisition algorithm composed of Partial Matched Filter (PMF) and Fast Fourier Transform (FFT) method. The algorithm changes the traditional two-dimensional searching strategy based on spread spectrum code phase and signal-carrier frequency into one-dimensional searching strategy based on spread spectrum code phase. Moreover, PMF not only consumes many hardware resources but also fails to acquire long period Pseudo-Noise (PN) code. Considering of these drawbacks, an improved algorithm is proposed by using folded matched filter and accelerating the operation speed. The results of test show that folded PMF saves hardware resources and achieves double parallel fast acquisition of carrier and PN code.