Modeling of a High-Frequency Hydroacoustic Communication Channel in Shallow Water of the Black Sea

A paper presents results of investigation of a high-frequency wideband hydroacoustic channel for high-speed communication with small ROVs using its model. A simulation is performed for typical conditions of the Black Sea in a warm season. A channel model takes into account multipath propagation due to reflection from the water surface and the bottom, a typical radiation pattern of high-frequency transducers, the Doppler effect due to the motion of the water surface and the receiver/transmitter fluctuation, wideband nature of the channel under consideration and the unevenness of its transfer function, in-band noise in the channel, acoustic wave speed profile inherent to the Black Sea in the warm season, as well as its salinity, pH, shallow water temperature. The model is implemented on the base of an open source software Bellhop and Acoustic Channel Simulator. The simulation results show that, if the channel occupies band 125-175kHz and the transmitter power is 150 dB µPa, the signal can be transmitted over 400m with signal-to-noise ratio up to 40 dB at the receiver side. At the same time, multipath propagation and non-stationarity due to motion, which are inherent to the channel, should be reduced for high-speed communication purpose. Reduction of unwanted rays strength using transducer with narrow beam pattern is shown during simulation.