A Method for Fast Acqusition of the PN Code in DS/SS System

In this paper a fast acquisition system is described for a DS-SS signal in the presence of a large Doppler shift.This technique is based on the FFT method.The maximum output of FFT module is selected as the estimation value of the present Doppler shift.In this situation,the system can test all the frequency offsets simultaneously.The theoretical simulation in a Gaussian channel of probability of detection and mean acquisition time is also presented in the paper.