Experimental validation of vector-based EB-ESPRIT technique for the localization of early reflections in a reverberant room

The eigenbeam (EB)-ESPRIT is one of the popular parametric direction-of-ofarrival (DOA) estimation techniques for a spherical microphone array. The EB-ESPRIT directly estimates the directional parameters by using a single recurrence relation of spherical harmonics, and has also been applied for the localization of early reflections in a reverberant environment. However, there are couple of limitations that hinder the use of the EB-ESPRIT for a real room data. The EB-ESPRIT exhibits a matrix ill-conditioning problem for sources positioned near the equator of the spherical coordinates, which can frequently occur by echoes impinging from those angles. Furthermore, the number of simultaneously detectable sources is also limited. To overcome these limitations, the vector-based EB-ESPRIT technique was introduced by utilizing three recurrence relations of spherical harmonics corresponding to x-, y-, and z- components of a vector in the Cartesian coordinates. In this work, we conduct experiments in a real reverberant room to validate the performance of vector-based EB-ESPRIT, and demonstrate that the vector-based EB-ESPRIT can successfully localize the first-order echoes from the data recorded in the reverberant room.