Design and simulation of a new model for shallow water multipath acoustic channel in the Persian Gulf

In this paper, for the purpose of investigating the horizontal sound propagation, based on the results obtained from practical measurements in the Strait of Hormuz and available data on sound speed variations at different depths, a comprehensive model for shallow water multipath acoustic channel is presented. The mathematical modeling of the multipath effect is based on the ray theory and the image method. In the channel modeling, the attenuation due to wave scatterings at the surface and their bottom reflections is accounted for. In addition, we consider the attenuations due to the absorption of sound by different materials and the presence of ambient noises such as the sea state noise, shipping noise, thermal noise and turbulence noise. Then, an underwater communication system consisting of a transmitter, channel and receiver is simulated. We use the Quadrature Phase Shift Keying (QPSK) modulation in the transmitter. In this case, data is transmitted at a rate of 5 Kbit/sec with a carrier frequency of 27 KHz for a maximum range of 1Km. The channel behavior recognition by the receiver is based on a training sequence which allocates the first 10% of the submitted signal to itself.