Direct and rapid p code acquisition technique

Abstract

As GPS P code has a higher chipping rate and better anti-jamming property than C/A code, it is desirable to military users. Traditionally, P code was not designed to facilitate direct acquisition but rather through handover from the short and periodic C/A-code. This needs long acquisition time and the acquisition is unavailable when C/A-code is jammed. Therefore, it is necessary to research the Direct and rapid acquisition technique for long code such as P code. An algorithm named Divided Folding Acquisition Search Technique is proposed here for P code. This method divides the local P code into n reference sequences. Then it makes a combined code sequence by folding and adding the n reference sequences as the new reference code sequence. Description of this algorithm and preliminary simulation are given. The analysis and simulation results show that the new algorithm reduces the acquisition time and improves the frequency searching precision.