Angle of Arrival Analysis for Underwater Wireless Optical Links

In underwater wireless optical communications (UWOC), each emitted photon will be scattered with a random deviated angle when propagating through underwater channel. Then the light beam observed at the receiver plane suffers spatial angle spread which follows a certain angle of arrival (AOA) distribution. In this letter, we present a closed-form expression of AOA distribution to characterize how received intensity of ballistic and single scattering components distributes over AOA with respect to unit transmit power. Numerical results have validated the proposed AOA distribution by Monte Carlo approach in clear and turbid coastal and harbor water with relatively short link range.