A Uniform Spatial Channel Model for Underwater Wireless Optical Communication Links

Abstract

In underwater wireless optical communications(UWOC), absorption and scattering cause attenuation and dispersion in both time and space domains. There have been many studies on temporal channel investigation and modeling such as impulse response but fewer on spatial behavior. In this paper, we consider the characteristics of actual light sources, i.e., laser diodes (LDs) and light-emitting diodes (LEDs), and propose a uniform spatial channel (USC) model for UWOC system employing single or multiple light sources. We first simulate the irradiance distributions of single-source UWOC systems based on Monte Carlo method and fit them with a closed-form expression for both types of light sources. Then we generalize this single-source model to multiple-source link geometry considering uniform linear array and circular array of light sources. Numerical results suggest that the proposed model fits well with the irradiance distributions of UWOC links regardless of the type, number and array geometry of light sources for various water types.