General Scintillation for Gaussian Beam Propagating through Oceanic Turbulence and UWOC System Performance Evaluation

TL;DR

This paper derives a comprehensive formula for scintillation index of Gaussian beams in oceanic turbulence, enabling better analysis and optimization of underwater optical communication systems.

Contribution

It presents a universal, exact expression for scintillation index considering real oceanic turbulence parameters and microscale effects, extending prior models.

Findings

Nonlinear relationship between Kolmogorov microscale and SI.

Oceanic turbulence parameters vary with depth and affect SI.

Derived expressions improve UWOC system design and performance prediction.

Abstract

In this paper, we derive a general and exact closed-form expression of scintillation index (SI) for a Gaussian beam propagating through weak oceanic turbulence, based on the general oceanic turbulence optical power spectrum (OTOPS) and the Rytov theory. Our universal expression not only includes existing Rytov variances but also accounts for actual cases where the Kolmogorov microscale is non-zero. The correctness and accuracy of our derivation are verified through comparison with the published work under identical conditions. By utilizing our derived expressions, we analyze the impact of various beam, propagation and oceanic turbulence parameters on both SI and bit error rate (BER) performance of underwater wireless optical communication (UWOC) systems. Numerical results demonstrate that the relationship between the Kolmogorov microscale and SI is nonlinear. Additionally, considering that certain oceanic turbulence parameters are related to depth, we use temperature and salinity data from Argo buoy deployed in real oceans to investigate the dependence of SI on depth. Our findings will contribute to the design and optimization of UWOC systems.