Photo-detector Selection in Cascaded Vertical Underwater VLC System

In this paper, we consider the photo-detector selection at the receiver in a vertical Underwater Visible Light Communication (UWVLC) system. In the considered vertical system, a laser source is located on the surface of sea water and N photo-detectors are placed at a few meters depth. The communication link between the laser and N-photo-detectors is considered as a cascade of non-mixing layers of water. The non-mixing layers are due to the in-homogeneous distribution of temperature and salt particles vertically. We assumed weak oceanic turbulence, therefore the cascaded channel is modeled with the multiplicative log-normal distribution. Further, we analyzed the outage probability, considering various depths of water with different fading coefficients. The derived results are validated with Monte Carlo simulations.