Performance Analysis on Delay-multiply Acquisition for Space-borne GNSS Receivers

Delay-multiply acquisition method is a well known acquisition method but is seldom used in ground GNSS receivers for the sensitivity loss introduced by the multiplication step. As to space-borne GNSS receivers, doppler offset may extend to tens of kHz due to rapid movement of space vehicles at a speed near the first cosmic velocity, which makes delay-multiply acquisition method a prior candidate for GNSS signal acquisition. In this work, we give a detailed mathematical analysis on the performance of delay-multiply acquisition method based on real data only. Comparisons are made between delay-multiply acquisition method and coherent integration acquisition method both in terms of detection probability and equivalent correlators. The results show that for space borne GNSS receivers, delay-multiply acquisition method is equivalent to millions of correlators which easily cancel its sensitivity loss side effect.