A Performance Comparison of Code Acquisition Techniques in DS-CDMA System

This paper compares parallel acquisition with hybrid acquisition in terms of mean acquisition time in code acquisition system of forward link and reverse link of direct sequence code division multiple access (DS-CDMA) system. The mean acquisition time of the hybrid and parallel acquisitions is derived from the distribution of the multiple correct code-phase offsets. Especially, the mean acquisition time of the hybrid acquisition scheme is derived by considering both case 1 (the correct code-phase offsets are included in one subset) and case 2 (the correct code-phase offsets exist at the boundary of two subsets), which are caused by the distribution of the correct code-phase offsets in the subset. Results are provided for the performance comparison between hybrid acquisition and parallel acquisition under the same hardware complexity in the forward and reverse links. In our performance evaluation of code acquisition in DS-CDMA system, the hybrid acquisition shows a better performance than the parallel acquisition in terms of mean acquisition time of the both links in the frequency-selective Rayleigh fading channel.