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

Addressed in this paper is a parallel code acquisition technique for M-ary orthogonal signals in a cellular code division multiple access (CDMA) syste m where pilot signal or preamble is not available for code acquisition. The proposed code acquisition system consists of parallel M-ary orthogonal dem odulators each having M correlators, The system also employs two operating modes, i.e., search and verification modes with the decision variables form ulated with successive maximums of M correlator outputs. The mean acquisiti on time is first derived for a multiple H-1 cell case and then the probabil ities of detection, miss, and false alarm are obtained for Frequency-select ive Rayleigh fading environments. Also provided is a computationally effici ent solution for detection performance analysis by using quantized decision variables. The performance of the proposed code acquisition technique is n umerically evaluated when it is applied to the initial acquisition of the m obile station requesting hand over.