Joint Energy and Correlation Detection Assisted Non-Coherent OFDM-DCSK System for Underwater Acoustic Communications

A joint energy and correlation detection aided orthogonal frequency division multiplexing differential chaos shift keying (JECD-OFDM-DCSK) system is presented in this paper, where the reference and information-bearing signals of JECD-OFDM-DCSK are superimposed in the same time slot so that the phase offset between the reference and information-bearing signals is addressed. In JECD-OFDM-DCSK, only some subcarriers are activated and additional information bits are transmitted by the indices of these activated subcarriers, thereby improving the data rate while reducing the energy consumption. The energy efficiency, peak to average power ratio (PAPR) performance and system complexity of JECD-OFDM-DCSK are analyzed and then compared to other systems. The comparison results show JECD-OFDM-DCSK can obtain higher energy efficiency and better PAPR performance compared to its competitors at the cost of higher system complexity. Furthermore, the bit error rate (BER) expressions of JECD-OFDM-DCSK are derived in additive white Gaussian noise (AWGN) and multipath fading channels. Simulation results show that the BER performance of JECD-OFDM-DCSK outperforms that of other OFDM-based DCSK systems. Finally, JECD-OFDM-DCSK performs much better than other systems over the underwater acoustic (UWA) channel, which validates the robustness of JECD-OFDM-DCSK.

Automated summary

This paper presents a joint energy and correlation detection aided orthogonal frequency division multiplexing differential chaos shift keying (JECD-OFDM-DCSK) system. The system superimposes the reference and information-bearing signals in the same time slot to address the phase offset issue. JECD-OFDM-DCSK improves the data rate and reduces energy consumption by activating only some subcarriers and transmitting additional information bits using their indices. The system is analyzed and compared to other systems in terms of energy efficiency, peak to average power ratio (PAPR), and system complexity. Simulation results demonstrate that JECD-OFDM-DCSK outperforms other OFDM-based DCSK systems in terms of bit error rate (BER) performance.