Design and Experimental Validation of Short Range Underwater Li-Fi Communication System

Abstract

Underwater communication is a a big challenge. The Radio waves do not travel proper in underwater because water conducts electricity and absorbs them faster . Acoustic modems can work over longer distances, but they are quite expensive, bulky, and slow since sound travels slowly underwater .In this paper , a simple and low-cost underwater optical communication system is designed that avoids the above mentioned issues by visible light for transmission of short text messages. This setup has two parts: a transmitter and a receiver, both built and programmed with the Arduino IDE. The receiver compares the signal to a threshold to decode the binary data back into text. The Serial Monitors at the transmitter and receiver represents the process of data transmission in real time Increasing the feedback resistor from 220 kΩ to 1 MΩ significantly improved range from few centimeters to meters and reliability. Adding double convex lenses on both ends focus and collects the light better, boosting signal quality even more. Overall, this work shows that underwater optical communication can be built inexpensively with easyto-find parts, making it a practical option for things like underwater sensor networks, diver communication etc