Analysis of aperture averaging effect and communication system performance of wireless optical channels with from weak to strong turbulence in natural turbid water

The aperture averaging technique can alleviate the effects of optical signal scintillation on the performance of underwater wireless optical communication (UWOC) systems. This paper derives a simplified formula that allows for an accurate and efficient analysis of the aperture averaging effect. Based on the OTOPS (oceanic turbulence optical power spectrum) model, the analytical formulas of the scintillation index from weak to strong turbulent channels for the optical signals of Gaussian, spherical and plane waves with the aperture averaging effect, are obtained. Then, the simple approximation expressions are deduced, which are appropriate to evaluate the performances of UOWC systems with the receiving aperture greater than 0.05 m and the link length not larger than 100 m, and simultaneously, they are proved by theoretical analyses and numerical processes.