Shallow water acoustic channel modeling and OFDM simulations

Underwater acoustic communication can be divided into two categories on the basis of water depth: shallow water and deep water communications, both have their own challenges to be dealt with. The effects of some factors are more in shallow water than in deep water like surface noise, temperature gradients, and impact of multipath propagation due to reflections. A simple and comprehensive underwater acoustic communication model is proposed here to reliably predict the propagation delay, transmission loss, multipath effect, ambient noise effect and bit error rate based on OFDM modulation for shallow water acoustic communication. MacKenzie' model is used to calculate the accurate speed of sound in shallow water and Wenz' model is used to find the effects of ambient noises. The widely used Thorp's model is compared with Fisher & Simmons' model to analyze the attenuation of the acoustic signal. Ray model is used as the basis of the multipath propagation modeling. Finally, performance of OFDM communication approach is simulated based on the shallow water acoustic channel model.