The performance analysis of rapid PN code acquisition using iterative message passing algorithm

Exact synchronization of PN code is the precondition of the excellences of spread spectrum communicating system, and how to rapidly and effectively make the PN code to exact synchronization becomes the key of the excellent performance of spread spectrum communicating system. After the analysis of simple serial acquisition and hybrid acquisition, this paper introduces a new acquisition method called rapid PN code acquisition using iterative message passing algorithm (IMPA). According to the channel message, rapid PN code acquisition using IMPA can obtain the local sequence directly which is roughly synchronous with the received sequence via iterative computations of the message above factor graph. The method changes generating mode of local sequence in traditional PN code acquisition algorithm. The paper shows the principle and the process of realization of the new approach, and carries out the simulation of performance of rapid PN code acquisition using IMPA, simple serial acquisition and hybrid acquisition. Simulation results show that the mean acquisition time of rapid PN code acquisition using IMPA is much shorter than both serial and hybrid search strategies. The detection probability of proposed algorithm is equivalent to the detection probability of simple serial acquisition.