Performance Analysis of Underwater Optical Wireless Communication Using O-RIS and Fiber Optic Backhaul (Extended version)

TL;DR

This paper introduces a hybrid underwater optical communication system combining optical access points with fiber-optic backhaul, employing reconfigurable surfaces and switching mechanisms to improve reliability and performance in challenging underwater environments.

Contribution

It proposes a novel hybrid UWOC system with O-RIS integration, passive/active configurations, and switching mechanisms, evaluated through analytical and simulation methods.

Findings

Optimal O-RIS placement improves performance.

Too close placement near receiver degrades signal due to path loss.

Increasing O-RIS elements enhances system adaptability.

Abstract

This Letter presents a novel hybrid underwater wireless optical communication (UWOC) system that integrates underwater optical access points (UOAPs) with a passive optical network (PON)-based fiber-optic backhaul to provide a resilient backbone. A hard switching mechanism is employed between direct and optical reconfigurable intelligent surface (O-RIS)-assisted links to ensure reliable connectivity. Unlike previous studies, the proposed system is evaluated under both active and multiple passive O-RIS configurations. To enhance reliability, the Selection Combining (SC) and Maximal Ratio Combining (MRC) schemes are applied. Analytical and simulation results demonstrate that optimal O-RIS placement significantly enhances system performance. However, in the linear regime, placing it too close to the receiver causes degradation due to increased path loss and beam jitter in an identical water type. Moreover, increasing the number of O-RIS elements within practical limits further improves overall system performance and enhances adaptability to variations in the underwater channel.