Class of novel broadband chaos‐based coherent communication systems

Abstract

As opposed to chaotic communication systems where a message signal directly modulates a broadband chaotic signal, it is also possible to indirectly utilise a chaotic signal to form a chaos-based communication system. This study proposes a class of novel broadband chaos-based coherent communication systems and demonstrates that their theoretical probability of error expressions match those of their counterpart conventional narrowband systems in the additive white Gaussian noise and the Rayleigh flat fading channel. The results are confirmed with the corresponding empirical bit error rate (BER) simulations. It is demonstrated that the chaos-based quadrature phase shift keying system offers an overall best performance while the chaos-based amplitude shift keying and frequency shift keying equivalent systems offer a possibility of performance optimisation. Most importantly, it is shown that the proposed systems outperform the chaotic communication systems in terms of BER while also being more practicable. The proposed systems thus hold high promise as the chaotic communication systems pose implementation difficulties, lack robust synchronisation techniques and are generally considered of academic interest only.