Weak DSSS signal acquisition with fine Doppler frequency estimation

An efficient acquisition method is proposed for high sensitivity and fine Doppler frequency estimation for direct-sequence spread spectrum signals. The proposed method first refines the Doppler frequency after a parallel code-phase search via triangle fitting of the cross-Ambiguity function. Then, the information of amplitude and frequency before and after the frequency refining is used to exclude the false alarm. Compared to traditional acquisition methods, the proposed method has higher sensitivity and Doppler frequency estimation accuracy. Simulation results verify the validity of the proposed method.