Design and analysis of an OFDM-based orthogonal multilevel code-shifted differential chaos shift keying

Abstract

In this paper, a new non-coherent <span class="il">chaos</span>-<span class="il">based</span> communication that combined <span class="il">Orthogonal</span> <span class="il">Multilevel</span> <span class="il">Code</span>-<span class="il">Shifted</span> <span class="il">Differential</span> <span class="il">Chaos</span> <span class="il">Shift</span> <span class="il">Keying</span> with <span class="il">orthogonal</span> frequency division multiplexing named (<span class="il">OFDM</span>-OMCS-DCSK) modulation system. New <span class="il">orthogonal</span> chaotic signal sets are generated by hybrid Gram-Schmidt algorithm <span class="il">and</span> Walsh <span class="il">code</span> function <span class="il">and</span> used it to carry high data rate in the same time slot. The Bandwidth efficiency <span class="il">of</span> the <span class="il">OFDM</span>-OMCS-DCSK system is comparing with conventional system. Also, the BER analytic expressions are derived under (AWGN) <span class="il">and</span> multipath Rayleigh fading channels <span class="il">and</span> comparing with the simulation results. Furthermore, the BER performance is compared with <span class="il">OFDM</span>-DCSK to found that the proposed system has the best BER performance with high data rate feature.