Design of DCSK based on modified time reversal technique

Abstract

In a Differential Chaos Shift Keying (DCSK) system, the reference and information chaotic bearing signals are transmitted in two consecutive time slots. This design requires twice the bit duration. In this paper, we present a system to double the data rate and enhance BER performance in Additive White Gaussian Noise (AWGN) channel. The system is based on adding reference signal and information bearing signal in one time slot without affecting its orthogonality. Information bearing signal is simply a time reversed and modulated version of the reference signal. The bit error performance of the proposed scheme, named Time Reversal Differential Chaos Shift Keying (TRDCSK), is studied analytically based on Gaussian Approximation (GA) for discrete time implementations. Excellent agreement between theoretical estimate and simulation results is obtained. Moreover, BER performance of the proposed scheme is compared with other differential coherent systems. Simulation results in AWGN channel environment show that TRDCSK outperforms the other standard systems at various $ {{E}_{b}}/{{N}_{o}} $ and with wide range of spreading factor values.

Keywords

• differential coherent system
• correlation
• chaos-based