A Study on Techniques of Underwater Optical Communication

Abstract

In recent years, the higher data rate and a higher degree of accuracy in transmissions have been achieved through wireless communication technology. The underwater communication is one of the trending technologies in wireless communication. The underwater data transmission is carried out by the acoustic waves which produce vibrations of sounds during its transmission. These vibrations have disturbed the creatures present underwater and additionally it may cause some noise. The results of many recent researches have concluded that the vibrations produced by the acoustic waves cause the disturbances in the earth plates and due to which the natural calamities like tsunami, earthquakes etc., have been occurring. The underwater communication is mostly used for military applications and for the transmission of sensitive information within the shortest distance of a particular area. The use of acoustic waves produces a low data rate and increased time delay. In addition to that, these waves are unreliable and complex due to multipath propagations in water. The acoustic waves employ modulation techniques like FSK, PSK and OFDM for the data transmission and consume more energy and power. So lately, the transmission of data in underwater is carried out by using the optical waves. ON–OFF keying technique is most commonly used modulation technique with attractive features such as high data rate, less delay, low power consumption, energy saving, and better accuracy than the other techniques.