The Effect of Medium Inhomogeneity in Modeling Underwater Optical Wireless Communication

Abstract

This paper introduces a stratified approach to modeling underwater optical wireless communication (UOWC). The influence of medium inhomogeneity, which many researchers ignore, was considered in modeling the UOWC channel to achieve an accurate model. The Monte Carlo technique to simulate the photon propagation was adapted to include medium inhomogeneity to estimate the received power, channel bandwidth, and delay spread of the proposed model. We use the depth-dependent chlorophyll profile that was established in Kameda empirical model to constitute the medium inhomogeneity. The empirical model used 0.5 mg m-3 and 2 mg m-3 of surface chlorophyll concentration to represent clear and coastal water. Besides, the comparison between collimated and diffused links was also studied to highlight the effect of the medium inhomogeneity on both links. Our findings indicate that the homogeneous model produces an underestimation result compared to the stratified model. The stratified model estimated significant increases in received power, lower delay spread, and higher bandwidth, which indicates the medium inhomogeneity is important for a realistic channel model.