INVESTIGATION OF VARIOUS MODULATION TECHNIQUES FOR UNDER-WATER COMM.

Abstract

Underwater laser communication is a very attractive and efficient way to communicate in ocean environment without disturbing the marine life. Though acoustic communication is very popular in this kind of communication system, the laser communication would be the best way for transmitting and receiving signal or data in deep oceanic environment due to higher bandwidth and security. This system would be suitable to transfer intelligence, surveillance and reconnaissance (ISR) data between ships and from ship to shore, and could be used by the Navy and the US Marine Corps. In this paper, we investigate the transmission efficiency, channel capacity, peak to average power ratio and bandwidth of various modulation techniques like OOK, PPM, DPPM, and DPIM. Experimental results, based on Lab VIEW and MATLAB simulation. Key Word: Pulse Time Modulation, on-Off keying, Pulse Position Modulation, Digital PPM, Digital Pulse Interval Modulation