Analysis of Underwater Acoustic Channel based on Angle of Arrival Distribution

Owing to the unique geometry of the underwater acoustic (UWA) channel, analysis based on the angle of arrival (AoA) distribution is fundamental. The energy in the UWA channel remains confined due to the geometry, and the number of interactions with the surface and bottom (also referred to as bounce) tends to be substantial. The acoustic signal undergoes coherent or incoherent scattering at the sea surface, depending upon the surface roughness before reaching the receiver. In this work, we derive the AoA distribution for incoherent scattering for a single bounce path. Channel characteristics such as the autocorrelation function (ACF) and Doppler spread (DS) based on the AoA distribution have been evaluated. Their significance and effect under different underwater geometries have been studied.