Underwater chaos-based DS-CDMA system

In this paper, an underwater chaos-based DS-CDMA system is proposed. This system adopts a novel spreading sequence called chaotic phase modulation (CPM) sequence. Comparing with conventional pseudo-noise (PN) sequences, CPM sequence possesses series of advantages, such as higher security, much more quantity available and smaller cross-correlation coefficient, etc. The bit error rate (BER) is compared between CPM and M sequence under Additive White Gaussian Noise (AWGN) channel. Simulation results show that CPM sequence behaves much better BER performance especially in the case of large number of users. Besides, it shows superior performance in time varying acoustic channels. Hence, the proposed chaos-based DS-CDMA system has potential applications in confidential underwater networks.