Adaptive Optics Effects on Average Channel Capacity of Oceanic Optical Wireless Communication Systems in Strong Turbulence

Abstract

The adaptive optics technique is employed in oceanic optical wireless communication (OOWC) systems to correct wavefront deformations (or aberrations) caused by oceanic turbulence. This way, intensity fluctuations (i.e., scintillation) or power loss in the received signal intensity are reduced, and thus the channel capacity is improved. In this study, the channel capacity of the OOWC system operating in strong oceanic turbulence is evaluated with and without adaptive optics compensation, then a performance comparison is made between the two on a percentage basis. For the channel capacity evaluations, the required optical entities, namely the scintillation index and the signal intensity are predicted by the help of the extended Rytov theory and the Huygens-Fresnel principle, respectively. Zernike filter functions are used to model the turbulence-induced deformations in the wavefront of the Gaussian laser and the operation of adaptive optics in this study can be described as the act of correcting aberrations.