Abstract: Pseudo-code acquisition is an indispensable and important part in short-time burst GMSK spread spectrum communication.Especially in the case of weak signal at the receiving end,Doppler frequency shift will seriously affect the performance of pseudo-code acquisition at the receiving end.Aiming at the particularity of short-time burst GMSK spread spectrum system,a pseudo-code acquisition algorithm at the receiving end is designed,and the relevant formulas of the acquisition algorithm are deduced and analyzed.On this basis,a multi-channel parallel receiving acquisition method is proposed to adapt to the short-time burst condition.This method improves the pseudo-code acquisition performance of the GMSK spread spectrum communication system by expanding the Doppler adaptation range.Applying this method to the short-time burst GMSK spread spectrum communication system can increase the pseudo-code acquisition peak threshold by about 2.7 dB to meet the system sensitivity requirements,and occupy less hardware resources.

Key words: Pseudo-code acquisition, Doppler shift, Spread spectrum communication, GMSK