Performance of RSMA-Based UOWC Systems Over Oceanic Turbulence Channel With Pointing Errors

Underwater optical wireless communication (UOWC) systems face significant challenges due to oceanic turbulence and pointing errors (PE), which can degrade system performance. Moreover, interference is another challenge in UOWC, considering the consistent increase in underwater optical devices. In this study, the performance of rate splitting multiple access (RSMA)-based UOWC systems is investigated over an exponential-generalized gamma (EGG)-distributed oceanic turbulence channel with generalized PE. The RSMA scheme is employed to facilitate communication between a source and multiple users in the UOWC system while accounting for the combined effects of oceanic turbulence and generalized PE. The statistical characterization of the UOWC system is analyzed, including the probability density function (PDF) of the signal-to-noise ratio (SNR), outage probability, throughput, and sum ergodic capacity. Additionally, closed-form expressions for the outage probability and throughput are derived, and asymptotic expressions for the outage probability in the high SNR regime are provided. Moreover, the diversity order of the system is evaluated, and the impact of different parameters on the system performance is discussed. Our results demonstrate the effectiveness of the RSMA-based UOWC system in mitigating the adverse effects of oceanic turbulence and PE while achieving improved performance in terms of capacity and outage probability. The findings of this study provide valuable insights for the design and optimization of UOWC systems in challenging underwater environments.