Modeling and Analysis of Underwater Optical Wireless Communication Channels

Abstract

Underwater optical wireless communication (UOWC) has emerged as a highly efficient method for high-speed, low-latency data transfer in underwater environments, driven by the growing demand for applications in environmental monitoring, underwater exploration, disaster prevention, and military operations. The deployment of UOWC systems, however, faces significant challenges due to the underwater medium's inherent complexities, including light absorption, scattering, and turbulence-induced fading. This paper offers an in-depth analysis and modeling of UOWC channels, employing theoretical and simulation-based approaches to evaluate critical channel parameters. Key factors such as water type, attenuation coefficients, scattering properties, and turbulence effects—modeled through log-normal, Gamma-Gamma, Generalized Gamma, and Weibull fading distributions—are analyzed to characterize signal propagation accurately. Using a 450 nm blue laser diode-photo-source (LD-PS) and an avalanche photodetector with a receiver sensitivity of -35 dBm, the study evaluates the performance of UOWC systems employing OOK modulation techniques under various environmental conditions. Comprehensive noise modeling includes thermal noise, dark noise, shot noise, and ambient light noise, all of which significantly influence communication reliability. The paper focuses on critical output metrics such as bit error rate (BER) and received power to assess system performance. Simulation results emphasize the challenges of achieving robust communication over extended distances and varying turbidity levels. By examining the interplay between optical path loss, turbulence-induced fading, and noise contributions, this work advances the understanding of underwater optical channels and provides valuable insights for optimizing UOWC system design. These findings lay the groundwork for future underwater communication systems that leverage optical signals for enhanced performance.