University of Cagliari
In these last years, many studies have focalized on the design of reliable under water acoustic communication systems. However, the ocean acoustic communication channel exhibits strong amplitude and phase fluctuations and the phenomena of diffraction, refraction and reflection. Due to the complexity of environment, the motions of transducers, sea surface, etc., the underwater acoustic signals exhibit random temporal and spatial frequency fluctuations in both amplitude and phase. These highly space, time and frequency dependent features introduce numerous obstacles for any attempts to establish reliable and long-range underwater acoustic communications.