A Trinal-Code Shifted Differential Chaos Shift Keying System

In the differential chaos shift keying (DCSK) system, half of the symbol period is used to transmit the reference signal, resulting in the poor energy efficiency. The existing DCSK-based systems also inherit this disadvantage, restricting the development of DCSK-based systems significantly. To tackle this issue completely, we propose a trinal-code shifted differential chaos shift keying (TCS-DCSK) system, where information bits are sorely transmitted by specific indices of Walsh codes and thus this system removes the reference signal. Comparison results of energy efficiency show that the TCS-DCSK system achieves higher energy efficiency in contrast to its competitors. In addition, we derive the bit error rate (BER) expressions of the TCS-DCSK system over additive white Gaussian noise (AWGN) and multipath Rayleigh fading channels. Finally, the BER performance of the TCS-DCSK system is compared to that of other systems. It is shown that the TCS-DCSK system can obtain considerable performance gain compared to other state-of-the-art chaotic communication systems.