Date Added: Oct 2010
In this paper, the authors present and analyze a secure spread spectrum communication system based on chaotic symbolic dynamics for an asynchronous multi-user case. This system performs without any need of a complex chaotic synchronization, and it integrates a spread spectrum unit using Gold sequences. This unit increases the security of transmission by reducing the probability of detection and achieves an efficient multi-user transmission. On the receiver side, the transmitted signal is first despread by the corresponding Gold sequence, followed by a maximum likelihood algorithm to estimate the chaotic sequence. The performance of the proposed system is analyzed under a pulsed-sinusoidal jammer, and an analytical bit error rate expression is derived.