Design and analysis of a novel differential chaos shift keying system with joint three-dimensional index modulation

This paper proposes a joint three-dimensional index modulation differential chaos shift keying system, referred to as JTDIM-DCSK. To meet the demands of high-speed communication, this system employs k-combination mapping at the transmitter to achieve three-dimensional index modulation of carriers, time slots, and Walsh codes. This significantly increases the number of implicitly transmitted bits and allows for the transmission of multiple physical modulation bits within a single selected time slot. Additionally, the receiver uses two noise reduction modules for the reference signal and Walsh code index detection signal, effectively reducing noise interference and improving bit error rate (BER) performance. The theoretical BER of the JTDIM-DCSK system is derived under additive white Gaussian noise (AWGN) and multipath Rayleigh fading channels, confirming its accuracy. Furthermore, the paper conducts a comparative analysis of the proposed system with other structurally similar systems in terms of data rate, spectral efficiency, complexity, and BER. The results highlight the overall superior performance of the JTDIM-DCSK system, providing strong support for achieving high-quality wireless communication.