Selection of Spreading Sequence Subsets for DS-CDMA Systems over Multipath Channels

The performance of a direct-sequence code division multiple access (DS-CDMA) system is largely dependent on the correlation properties of the spreading sequences in use. Given a set of sequences, it is thus important to select an appropriate subset for optimal performance. In this paper, two new selection criteria of sequence subsets are given for synchronous and asynchronous DS-CDMA systems over multipath fading channels respectively when the multipath intensity profiles (MIP) are known. Simulation results show that subsets of sequences based on the proposed selection criteria can provide better bit-error rate (BER) performance than those based on the existing mean-square correlation selection criteria