Time delay estimation using integrated polyspectrum

The problem of estimating the difference in arrival times of a non-Gaussian signal at two spatially separated sensors is considered. The signal is assumed to be corrupted by spatially correlated Gaussian (or a class of non-Gaussian) noise of unknown cross-correlation. The authors present two new frequency-domain approaches for differential time-delay estimation using bispectrum or integrated bispectrum of the measurements. The approaches are asymptotically maximum-likelihood, hence, are optimal unlike the existing frequency-domain (bispectrum-based) approaches. Unlike the existing time-domain approaches, the input does not need to be a linear process