A Square-Constellation-Based $M$ -Ary DCSK Communication System

In this paper, a square-constellation-based M-ary differential chaos-shift-keying (M-DCSK) communication system framework is proposed. The symbol-error-rate expression of the proposed system is derived over additive white Gaussian noise as well as multipath Rayleigh fading channels. Moreover, the peak-to-average-power-ratio (PAPR) performance is carefully analyzed for the newly proposed system. Based on the square-constellation-based M-DCSK framework, a simple least-square estimator is designed to demodulate the information exploiting pilot-assistant symbols. Analytical and simulated results show that the proposed system benefits from a lower energy consumption, but suffers from a higher PAPR compared with the circle-constellation-based M-DCSK system.