General Iterative Receiver Design for Enhanced Reliability in Multi-Carrier Differential Chaos Shift Keying Systems

In this paper, we present a general iterative receiver for multi-carrier differential chaos shift keying (MC-DCSK) systems. The imperfect channels conditions may induce transmission errors which will degrade the reliability performances. In order to address this issue, we propose an iterative demodulation structure to improve bit error rate (BER) performances by improving the signal to noise ratio (SNR) of reference chaotic signals. At the presented iterative receiver, we propose to evaluate correlation coefficients between the reference chaotic signals and each information-bearing chaotic modulated signal. Then they are used to update and feedback the reference chaotic signal for the next iteration. With the aid of the renewed reference signals, a similar procedure is carried out until the iteration stopping criteria is reached and the threshold decisions are provided. The presented general iterative receiver can be applied to any MC-DCSK systems without introducing any additional modules at transmitters. Theoretical analysis is provided to prove the iteration convergence and to derive the BER performances. Simulation results verify the effectiveness of the theoretical analysis, which demonstrates that better reliability performances can be achieved over additive white Gaussian noise (AWGN) and fading channels compared with counterpart systems.