On correcting the phase bias of GCC in spatially correlated noise fields
Xi-Lin Li · Signal Processing · 2020
Generalized cross correlation (GCC) is arguably the most widely used time difference of arrival (TDOA) estimators. Most studies on GCC assume spatially uncorrelated noises, and focus on the design of weighting functions. However, real world noises tend to be spatially correlated, and such correlation introduces phase bias to the cross phase spectra used in GCC. This paper proposes a simple closed-form maximum likelihood (ML) cross phase spectra estimator for GCC by only assuming the prior knowledge of noise spatial complex coherence function, which can be predicted in theory or measured in advance. TDOA estimation experimental results on real world speech recordings confirm the usefulness of this simple new phase estimator.