Effect of transmitter divergence-angle on the performance of underwater visible light communication system.

Underwater visible light communication emerges as a promising technique to enhance the capacity of underwater wireless communication networks for upcoming generation. Major technical problem with underwater visible light communication systems in motion is the pointing, acquisition, and tracking. To ease pointing, acquisition, and tracking, hence it is important to navigate optical information beam over broad range and adjust the transmitter beam divergence angle according to the link condition, which is adjusted by the Optisystem software. In this paper, performance comparison among wide range of transmittance optical beams in underwater visible light communications system for high-speed communication is presented for PIN as well as for Avalanche photodiode. The effect of using variable transmittance beam-divergence angle on the bit-error rate, signal-to-noise ratio, communication link distance is also investigated. OptiSystem and MATLAB software is used to implement the underwater visible light communication transceiver system. Finally, it is shown in the paper that in the presence of pointing errors, adaptive beam control techniques improve the performance of high-speed Underwater visible light communication system. [ABSTRACT FROM AUTHOR]