Performance comparison of chaotic spreading sequences generated by two different classes of chaotic systems in a chaos‐based direct sequence‐code division multiple access system

Abstract

In the world of wireless communications, achieving a highly secure transmission at the lowest possible performance degradation has presented a major challenge and a number of conventional direct-sequence-code division multiple access (DS-CDMA)-based solutions have been put forward that deals with the issue. This study aims to overcome the challenge by introducing a new approach that employs a chaotic sequence in DS-CDMA system over fading channels. The proposed algorithm, which assumes a perfect sync between the transmitter and the receiver, generates a binary code by using a three-dimensional (3D) chaotic system. Simulations based on a flat-fading channel with additive white Gaussian noise and inter-user interference reveal that the new approach outperforms codes generated by other classes of chaotic systems, that is, the 1D chaotic system. The results also proved the proposition's performance is comparable to conventional pseudo-noise spreading codes, the Gold code, in several key aspects including security of transmission, bit-error rate, code generation speed and the number of possible code sequences.