| The elements required for simulation of an underwater acoustic communications system test environment are developed. Pulse shaped, spread-spectrum, phase shift keying transmit waveforms are discussed. An underwater acoustic channel model is detailed including empirically derived spreading, absorption and noise power spectral density models. A method of noise process generation given a noise power spectral density is discussed and an algorithm is presented with guidelines for its successful implementation. The process of signal demodulation, using matched and MMSE filter receivers, is then discussed. Finally, simulation products are presented that including bit error rate as a function of propagation range and carrier frequency as well as comparisons of generated noise process power spectral densities with the theoretical model. |
