Time Delay Estimation Using Spatial Correlation Techniques

ABSTRACT Recently there has been an increasing interest in the use of the TDE technique to locate and track acoustic sources in a conferencing environment. Typically, the delay estimate is obtained as the time-lag that maximizes the cross-correlation function between the filtered versions of two received signals. This so-called generalized cross-correlation technique, based on the measurements provided by two sensors, however, suffers significant performance degradation in the presence of reverberation. In this paper, the idea of cross-correlation coefficient between two signals is generalized to the multichannel case by using the notion of spatial prediction. The multichannel spatial correlation matrix is then deduced and applied for the purpose of TDE. It is shown that this new method can take advantage of the redundant information provided by multiple microphone sensors to help the estimator to better cope with reverberation and noise.