Attenuation analysis of an underwater optical wireless communication system, based on red light-emitting diodes, in turbid water with preliminary uncertainty analysis

Underwater communication traditionally relies on acoustic systems, which suffer from high energy consumption, significant latency, and undesirable environmental impact. Optical wireless communication (OWC) technologies represent a promising alternative, yet they are strongly limited by light attenuation in water, especially under turbid conditions. In this work, an innovative low-cost underwater optical wireless communication (UOWC) system based on red LEDs (light-emitting diodes) and photodiodes was developed, allowing not only data transmission, but also experimental characterisation of signal degradation in turbid water. The system was tested by varying the concentration of suspended clay to evaluate the reduction in optical intensity and data transmission rate. Results show a maximum data rate of 1.5 Mbit/s in clear seawater, followed by an exponential decrease in performance as turbidity increases. The proposed approach provides a reproducible and low-cost method for studying the underwater optical channel and represents a foundation for future developments aimed at optimising UOWC systems in more complex and realistic scenarios.