Performance Analysis of Mode Division Multiplexing-Based Underwater Optical Wireless Communication Systems in Varied Water Types

Abstract

Underwater optical wireless communication (UOWC) employs light signals to transmit data at high speeds in aquatic environments, enabling rapid and low-latency connectivity. This technology supports critical applications such as marine exploration, environmental monitoring, and underwater robotics, despite challenges like light absorption and scattering. UOWC systems have gained significant attention for their high data rate capabilities in underwater environments. This paper presents a comprehensive performance analysis of a mode division multiplexing (MDM)-based UOWC system employing four distinct Hermite-Gaussian (HG) modes, each supporting independent 10 Gbps data streams. The study evaluates the system's performance in diverse water conditions, including Pure Sea, Coastal Sea, Clear Sea, and Harbor waters. Key performance metrics such as bit error rate (BER) and Q factor are analyzed against increasing link ranges for each water type. The results demonstrate that all the 4-HG beams perform similarly under the effect of oceanic turbulence. The results demonstrate that the proposed system transmits 40 Gbps data up to 21.5 m under pure sea conditions which reduces to 15 m under clear ocean, 9.8 m under coastal ocean, and 5.6 m under Harbor I conditions, and 3.6 m for Harbor II conditions with acceptable Q factor $˜$ 4 dB and BER $\le {10}^{-3}$. Results demonstrate the impact of varying absorption and scattering properties of water on system performance, providing valuable insights into the feasibility and optimization of MDM-based UOWC systems for underwater environments. The findings highlight the potential of MDM techniques to enhance data transmission efficiency and reliability across diverse underwater conditions, paving the way for advanced underwater communication networks.