Source Localization in Reverberant Environments : Part II - Statistical Analysis

The main di culty in building robust practical systems for acoustical source localization using microphone arrays, is the e ects of room-reverberation. In this paper, a statistical analysis is presented of the in uence of room reverberation on source localization techniques. Using a statistical reverberation model presented in a companion paper, the Cram erRao lower bound for time-deley estimation and maximum likelihood estimators are derived. The probability of a large error is investigated, and also the performance of common time-delay estimation techniques is analyzed. An interesting outcome of the analysis is that the so-called PHAT time-delay estimator is shown to be optimal among a class of cross-correlation based time-delay estimators.