Research on fast acquisition algorithm of spread spectrum signal based on PMF-FFT

Abstract

Aiming at the attenuation problem when doppler frequency shift is large, pmF-FFT algorithm based on matched filter is introduced to compensate the attenuation of matched filter through FFT method, but at the same time, PMF-FFT algorithm also introduces scallop loss due to the introduction of FFT operation. In this paper, the mathematical model of PMF-FFT algorithm is given, the basic principle of acquisition is analyzed, and the characteristics of amplitude-frequency response are deduced and analyzed mathematically. Aiming at the selection of partial matched filter length in the design of PMF-FFT capture system, this paper studies the influence of the change of partial matched filter length on several performance indexes, and gives the selection criteria of partial matched filter length. In this paper, the scallop and related losses in PMF-FFT algorithm are compensated in two ways: adding zero and adding window. Finally, the performance of the improved algorithm is analyzed, and it is proved that the improved algorithm has better performance than the original algorithm. At the same time, several performance indexes are proposed, which proves the superiority of the improved algorithm.