Blind Adaptive Multiuser Detection for Chaos CDMA Communication

Chaos-based CDMA communication has opened up a new category for spread spectrum communication, where the spreading code that is used to scramble data in the CDMA systems can be generated using a single mathematical relationship of a chaotic generator instead of using the pseudo-noise (PN) generator. Recent studies showed that this sequence can enhance the security and increase the capacity of the system at the physical link due to its bifurcation behavior. In this paper, we investigate the performance of multiuser detection schemes in chaos based and PN code-division multiple access (CDMA) systems. Two well- known schemes are applied and compared: adaptive filtering using the constant modulus algorithm (CMA) and matched filtering (using a correlator). Simulation results showed that, for both schemes, the chaos-based CDMA outperforms the PN-based CDMA in terms of bit error rate (BER) and mean-squared error (MSE).