A parallel code acquisition technique for M-ary orthogonal signals in a cellular CDMA system

Abstract

Addressed in this paper is a parallel code acquisition technique for M-ary orthogonal signals in a cellular code division multiple access (CDMA) system where pilot signal or preamble is not available for code acquisition. The proposed code acquisition system consists of parallel M-ary orthogonal demodulators each having M correlators. The system also employs two operating modes, i.e., search and verification modes with the decision variables formulated with successive maximums of M correlator outputs. The mean acquisition time is first derived for a multiple H/sub 1/ cell case and then the probabilities of detection, miss, and false alarm are obtained for frequency-selective Rayleigh fading environments. Also provided is a computationally efficient solution for detection performance analysis by using quantized decision variables. The performance of the proposed code acquisition technique is numerically evaluated when it is applied to the initial acquisition of the mobile station requesting hand over.