Code acquisition system using periodic property of PN code in Rayleigh fading channel

In this paper, we present a performance analysis of a serial acquisition system with an AWGN rejection filter using the periodic property of a PN code in the Rayleigh fading channel. The AWGN rejection filter is utilized to evaluate a running average value of the received signal for the noise rejection. In addition, we describe a robust acquisition scheme using the AWGN rejection filter and reference filter for fast and reliable acquisition. The reference filter is employed to estimate the noise variance at the output of the matched filter for the variable threshold. The results show that the mean acquisition time of serial acquisition with the AWGN rejection filter is reduced compared with the conventional serial acquisition system in low E/sub c//N/sub 0/ regions, and that with approximately the same degree of the mean acquisition time of the robust acquisition scheme with AWGN rejection filter and reference filter is comparable to the mean acquisition time of serial acquisition with the AWGN rejection filter. Thus, a robust acquisition scheme using the AWGN rejection filter and reference filter is faster and more reliable scheme than serial acquisition with an AWGN rejection filter in the Rayleigh fading channel.