Computationally efficient simulation of underwater acoustic communication systems

We propose a statistical model for underwater acoustic channel simulation which addresses acoustic propagation laws as well as fading. The fading effects are studied on small-scale (involving distances on the order of the wavelength) and large-scale (due to location uncertainty). These effects are caused by various phenomena such as scattering, system motion and changing environmental conditions, and result in the variation of the instantaneous channel response as well as the average signal to noise ratio. We compare the simulator with real underwater acoustic data obtained during the Kauai Acomms MURI (KAM'11) experiment which was held in July 2011. Simulated and experimental channels exhibit complex Gaussian path fading with a Bessel-type time-correlation on the small scale, and log-normal distribution with an exponentially decaying time-correlation on the large scale. MSE performance is compared for coherent and differentially coherent detection of experimental and simulated data.