Design and Performance Analysis of Multilevel Code-Shifted $M$ -Ary Differential Chaos Shift Keying System

The multilevel code-shifted differential-chaos-shift-keying system transmits multiple information-bearing chaotic signals together with a reference chaotic signal in the same transmission symbol duration by orthogonal code sequences of a Walsh matrix. In order to obtain higher bandwidth efficiency (BE), a multilevel code-shifted M-ary differential chaos shift keying (MCS-MDCSK) system is proposed in this brief. We derive the theoretical bit-error-rate (BER) formula for the proposed system over the additive white Gaussian noise channel and the multipath fading channel. Finally, numerical results verify our derivations and superiority of the MCS-MDCSK. The proposed system not only greatly boosts the BE, but also obtains better BER performance.