Study and Analysis of Modulation Schemes for Underwater Optical Wireless Communication

Communication technology is poised to play a crucial role in advancing the study of climate change, facilitating the monitoring of shifts in biological, biogeochemical, evolutionary, and ecological aspects within marine and oceanic environments. Additionally, it is imperative to ensure the efficient operation of underwater sensor networks, unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, existing underwater acoustic communication technology falls short of delivering the high data rates required for comprehensive investigation and surveillance in these environments and facilities. In response to this challenge, optical wireless communication has emerged as a promising alternative. This study focuses on the design and examination of an underwater optical communication link capable of communication over a horizontal distance of up to 130 meters at a depth of 40 meters. The proposed system is rigorously assessed under clear ocean conditions, considering a bit rate of 15 Gbps and employing both Differential Quadrature Phase Shift Keying (DQPSK) technique and Orthogonal Frequency Division Multiplexing-Quadrature Amplitude Modulation (OFDM-QAM) technique.