Study On The P Code Acquisition Algorithm Of GPS Receiver

Spread spectrum communication technology is based on Claude E.Shannon's information theory, and compared with other communication technologies, which has the advantage of low probability of intercepting, a high immunity to interference, hiding the useful information and multiple-access communication ability. Now this technology has been applied in various communication fields.Compared to other communication technologies, Spread Spectrum(SS) technology has the advantages of low probability of intercepting, a high immunity to interference, hiding the useful information and multiple-access communication ability. In modern information times, it has been one of the three high-technological communication means and is developing from military use to commercial environment. In this paper, the author mostly research on Direct Sequence Spread Spectrum (DSSS), the most ordinary one within Spread Spectrum techonologies.Based on analyzing and contracting the ways referred by thesis and paper on GPS, this paper proposes a way of direct acquisition of the GPS P code. It is a way that uses FFT to achieve Circular Correlation by partition and zero padding (CCPAZP) and achieve frequency synchronisition. In this way, acquisition can be achieved very fast as it transfers two-dimensional search into parallel one-dimensional search. Also, it can be easily implemented in real GPS project for its low need in hardware resource. In the end, this paper gives the simulation result and the implemention result.The synchronisition ways proposed in this paper are all based on real project need. So it can be used in real GPS project, such as GPS receiver synchtonisition, GPS control and receiving base synchronisition.