A Novel Noise Reduction Differential Chaos Shift Keying System Based on Quadrature Modulation

Abstract

To overcome the shortcomings of low transmission rate of Noise Reduction Differential Chaos Shift Keying (NR-DCSK), a novel Noise Reduction Differential Chaos Shift Keying system based on Quadrature Modulation (QM-NRDCSK) is proposed. The generator generates two chaotic sequences, the reference signal of each channel is P-time repetition of the information-bearing signal. The information of different users is distinguished by different time slots, and the two signals are transmitted on the same frequency band by using quadrature modulation. The reference signal of each channel is averaged P times by the moving average filter at the receiving end, and then non-coherently demodulated with the information signal. The correctness of the theoretical derivation is verified by simulations in AWGN and multi-path Rayleigh fading channels, and it shows that the system can effectively improve the transmission rate and has better bit error performance while having high spectrum utilization.