On the Statistical Modeling of the Underwater Optical Wireless Channel Subject to Air Bubbles

Abstract

In underwater wireless optical communications (UWOC), the obstruction of light propagation by air bubbles is one of the main factors which causes light power to fluctuate at the receiver. In this thesis, we construct a statistical model for the received power in the presence of air bubbles. First, we postulate some random variables based on some real experiments, such as the size of a bubble, the generation of each bubble, and the horizontal and vertical movements of a bubble. Second, we mathematically express the amount of obstructed power which the shade of each bubble causes over the beam area and sum them all up to get the total obstructed power. In order to use the method of moments, we find the expectation, the second and/or the third moments of the total obstructed power. Lastly, we use these two or three moments of it to find suitable distributions that match the simulation data, which are the Weibull distribution and Generalized gamma distribution respectively. With these distributions, we construct the statistical model of the received power. Furthermore, we show that those distributions fit well to the simulation data.