A Bayesian dynamic time warping approach for nonuniform Doppler paths in acoustic multipath channel

Abstract

The estimation of Doppler effects is indispensable to many acoustic signal processing applications including reliable underwater acoustic communication. Computationally expensive ambiguity-function based methods have good performance in estimating slowly varying uniform Doppler shifts. However, for highly reverberant environments such as in shallow water acoustics, there has not been a robust approach to estimate non-uniformly time varying Doppler along each of the different propagation paths. In this paper, we propose a multidimensional dynamic time warping (DTW) algorithm to precisely estimate non-uniform time varying Doppler in acoustic multipath channels. The proposed algorithm exploits a Bayesian approach to map multidimensional temporal scaling, while guaranteeing polynomial time complexity in the length of the signal. Both simulation and experimental results for signals received from moving sources in confined reverberant spaces will be provided to show the capability of the proposed approach.