Effective acquisition of a phase-coherent DSFH satellite telemetry signal

A hybrid direct sequence and frequency hopping (DSFH) spread spectrum signal can greatly improve ranging precision and jamming resisting capability in spacecraft telemetry. The frequency hopping adds another searching dimension to acquisition and increases the acquisition complexity. Therefore, this paper designs an phase-compensating-based effective acquisition algorithm. First, the model DSFH telemetry signal is introduced. Then the auto-correlation function and the acquisition problem are analyzed. Finally, a phase-compensating-based acquisition algorithm is proposed, its computation complexity is analyzed, and the signal-to-noise ratio(SNR) losses due to necessary approximations are shown. The proposed method can be modified to adapt to different PN chip rates and frequency hopping rates.