Amelioration of Acquisition of a Degraded Signal in a GNSS Receiver Embeded in an Observation Satellite by Using Double Bloc Zero Padding Method (DBZP)

In this paper, we study the acquisition of signal in a GPS (Global Positioning System) receiver on board of an observation satellite that receives information on a carrier wave L1 frequency 1575.42 MHz .We simulated GPS signal acquisition. This allowed us to see the behavior of this type of receiver in AWGN channel. Block Zero-Padding (DBZP) acquisition method, known for his efficiency, is deeply analyzed to highlight the acquisition of the modernized GNSS signals can be seriously degraded by the presence of bit sign transitions at each spreading code period. It appears clear that there is a need to use an acquisition method which is bit sign transition insensitive. To tackle this problem an improved and innovative acquisition method, the Double-Block Zero-Padding. Besides this major improvement, other developments are proposed to limit losses on the acquisition performance, in. This paper we will focus on the study of the acquisition of weak signals. The performance study and the results point out the efficiency of this method for the acquisition signals, in comparison with a classical acquisition method which is also data insensitive.