Code acquisition of direct-sequence spread spectrum communication with Doppler shift

Abstract

We analyze the performance of the single dwell code acquisition in severe Doppler environment. Both the carrier frequency offset and code frequency offset due to the Doppler effect are taken into account. The effect of the code Doppler gives rise to the code chip slipping during the correlation process. Moreover, the power reduction through the bandpass filter caused by the carrier Doppler can degrade the acquisition performance significantly. However, this issue can be alleviated by properly choosing the bandwidth of the bandpass filter in the acquisition loop. Results are presented for cases which show that the acquisition loop can tolerate Doppler frequency offset at the price of a slight performance degradation.