A rapid adaptive PN code acquisition with antenna diversity for DS-CDMA communication

In this paper, we propose an adaptive PN code acquisition scheme, named FAHAP (fuzzy adaptive hybrid acquisition processor). The proposed system combines an antenna diversity technique and a hybrid search scheme. Two fuzzy adaptive detectors (CA-CFAR and OS-CFAR) are used. Each detector computes the value of the membership function spanned by the false alarm space from the reference cell samples and transmits it to the fuzzy fusion center. We use two levels of the fuzzy fusion to derive the global membership function. The performance of the proposed acquisition scheme is analyzed in frequency-selective Rayleigh fading channels. The simulation results show that the FAHAP processor significantly outperforms the conventional schemes. The effects of the degree of parallelism, the number of resolvable paths, the signal-to-noise ratio (SNR) and the number of antennas on the acquisition performance are also investigated.