Experimental investigation of underwater turbulence effect on BER for orthogonal OOK modulation

Underwater laser communication is a very attractive and efficient way to communicate in oceanic 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 turbulence effect of sea water and clean water on underwater laser propagation for different temperatures and other variables. As the underwater laser links are being considered for naval applications, we demonstrate a novel Orthogonal On-Off Keying modulation technique [8], which is also bandwidth efficient. At the received side, the data is recovered by means of code correlation. The proposed technique offers error control coding and synchronization on the same platform. Experimental results, based on LabVIEW and MATLAB simulation, are presented in terms of Fourier analysis to illustrate the concept.