Performance Evaluation of Acoustic Model-Based Blind Channel Estimation in Ocean Waveguides

Blind channel estimation (BCE) which does not require the knowledge of the source signals becomes increasingly important in various underwater acoustic applications. Unlike the conventional methods that utilize the statistical properties of the received signals, this paper proposes an acoustic model-based BCE method that exploits the properties of the acoustic propagation and the acoustic environmental information. This method is implemented by localizing the source with a matched-field processing algorithm first, then, uses the physical model of the ocean waveguides to determine the channel impulse response. Its performance is investigated by making comparisons with the mode-based artificial time reversal and the ray-based synthetic time reversal methods, using the array data measured from the SWellEx-96 experiment at four source-array ranges. Cross-correlation coefficient and normalized projection misalignment are adopted to evaluate the performance of the proposed method, and the simulation results for different multipath channels confirm the effectiveness of the proposed method.