Performance analysis of high-altitude platform-underwater wireless optical communication systems with decode-and-forward relaying

We conduct a performance analysis of a dual-hop high-altitude platform-underwater wireless optical communication (HAP-UWOC) system employing decode-and-forward relaying. Realistic channel conditions are modeled by the system, such as combined absorption, scattering, and turbulence for the UWOC link and gamma–gamma fading for the HAP link. Meijer’s G-functions are used to derive closed-form expressions for average bit error rate and outage probability, which provide analytical insight into channel impairments. Strong agreement is found when results are validated using Monte Carlo simulations for different types of underwater, including turbid harbor, coastal, and clear ocean. Our results demonstrate that the UWOC link has a major effect on the overall performance of the system, particularly in the presence of extreme turbulence. Under combined atmospheric and underwater fading conditions, the suggested model provides improved analytical tractability in comparison to current methods.