DOA estimation with histogram analysis of spatially constrained active intensity vectors

The active intensity vector (AIV) is a common descriptor of the sound field. In microphone array processing, AIV is commonly approximated with beamforming operations and utilized as a direction of arrival (DOA) estimator. However, in its original form, it provides inaccurate estimates in sound field conditions where coherent sound sources are simultaneously active. In this work we utilize a higher order intensity-based DOA estimator on spatially-constrained regions (SCR) to overcome such limitations. We then apply 1-dimensional (1D) histogram processing on the noisy estimates for multiple DOA estimation. The performance of the estimator is shown with a 7-channel mobile microphone array, in reverberant conditions and under different signal-to-noise ratios.