Performance Analysis of Multi-Hop Underwater Wireless Optical Communication Systems Over Exponential-Generalized Gamma Turbulence Channels

Underwater wireless optical communication (UWOC) has generated a much interest in the research community thanks to its wide range of applications, including submarine navigation, seafloor exploration, and military operation. Turbulence, scattering, and absorption phenomena generally can severely affect the performance of UWOC systems. The relaying methods have been shown as a promising technique to alleviate turbulence-induced and short-range fading. In this paper, under varying channel conditions, we present a unified framework to analyze the performance of multi-hop UWOC systems with both amplify-and-forward and decode-and-forward relaying techniques. In particular, for the end-to-end signal-to-noise ratio (SNR), we use the univariate and bivariate Fox-H functions to derive both the probability density function (PDF) and cumulative distribution function (CDF). Furthermore, for the performance of systems under both types of relaying techniques, we derive tight mathematical expressions for the outage probability and bit error probability. Besides, to highlight and provide some prominent engineering insights into the diversity order, an asymptotic analysis for the outage likelihood and average bit error rate (BER) is given. Consequently, results from Monte-Carlo simulations are used to verify the correctness of our derived mathematical expression.