New algorithms for constructing quasi-optimal subfamilies of GMW sequences for the applications in finite CDMA systems

Abstract

GMW sequence possesses desirable 2-valued auto-correlation functions however with less well controlled cross-correlation functions. This paper studies several algorithms for constructing those quasi-optimal sub-families in terms of minimized bit error rate under co-channel interference. The results show that performance of resultant sub-families is very sensitive to the algorithms and sub-family sizes. A new criterion based on combinational (even plus odd) maximum cross-correlation is introduced for code selection and the resultant highest-peak-deleting and most-peak-deleting algorithms are effective.