A Single-Carrier Delay-and-Superposition Based High Spectral Efficiency Differential Chaos Shift Keying for Maritime Internet of Vessels

The fast growing Internet of Vessels (IoV) requires maritime communications to be more spectral efficient to make full use of the scarce maritime spectral resource, provide a high data transmission rate and support massive communication nodes to access the network. However, the spectral efficiency of most existing maritime communications are still relatively low, and consequently maritime communications can hardly support high volume multi-user communications. Therefore, in this paper, a high spectral efficiency Differential Chaos Shift Keying system based on a single-carrier delay-and-superposition modulation technology (SCDS-DCSK) is proposed for IoV scenarios. In a SCDS-DCSK symbol, all sub-carriers have the same frequency, indicating that the symbol of SCDS-DCSK only occupies the bandwidth of a single sub-channel. As a result, a large amount of maritime communication resources can be saved for accommodating more communication nodes and the spectral efficiency is significantly improved. System architectures and principles are firstly demonstrated. Then, the spectral efficiency, peak mean power ratio (PAPR), complexity, and the origin of error bits of SCDS-DCSK are analyzed, and the bit-error-rate expressions are derived. Moreover, effects of various system parameters and levels of sea states on the system performance are simulated and discussed. Simulation results verify the theoretical analyses, and manifest that the SCDS-DCSK can achieve a high spectral efficiency under various sea states. Thanks to characteristics such as high spectral efficiency, flexible parameter configuration, and simple implementation, SCDS-DCSK is a promising technology for improving the quality of service (QoS) of future maritime IoV.