Design of high speed underwater optical communication using On-Off keying algorithm

Abstract

The growing need for underwater observation and subsea monitoring systems have stimulated considerable interest in advancing the technologies of underwater wireless communication. This communication technology is expected to play an important role in investigating climate change, monitoring biogeochemical, ecological and biological change in the ocean and lake environments, which helps to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), ships, buoys, and submarines. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environmental factors. To overcome this problem, Optical wireless communication has been proposed as the best alternative to meet this challenge. In this paper, optical communication using LEDs is presented as an advancement over acoustic modems for scenarios where high speed but only limited access applications is required and also lower power, less complex communication systems are desired. On the basis of Beer-Lambert's law it was deduced that blue light (470 nm) of the visible spectrum suffered the least attenuation underwater. We attempt to design an ultra-bright blue LED based transmitter system by optimizing it with opto-coupler and an enhanced photodiode based receiver system are developed with the goal of transmitting data at higher rates by using On-Off keying technology. The objective was to transmit the data at a rate of at least 1 Mbps over a distance of 30 meters. Here, real time data could be sent or received with the help of simulation results.