Direction of Arrival Estimation of Wide-band Signals with Planar Microphone Arrays

TL;DR

This paper introduces a novel algorithm for estimating the unambiguous direction of arrival of wide-band signals using a single planar microphone array, effective in noisy conditions and without prior source location knowledge.

Contribution

The proposed method uniquely combines pair-wise time delay estimates to determine an unambiguous DOA with no need for prior source location information.

Findings

Robust against noise with a 3:1 error ratio

Achieved DOA estimation standard deviations between 15.2 and 20.4 degrees

Suitable for wide-band signals using cross-correlation for TDEs

Abstract

An approach to the estimation of the Direction of Arrival (DOA) of wide-band signals with a planar microphone array is presented. Our algorithm estimates an unambiguous DOA using a single planar array in which the microphones are placed fairly close together and the sound source is expected to be in the far field. The algorithm uses the ambiguous DOA estimates obtained from microphone pairs in the array to determine an unambiguous DOA estimate for the array as a whole. The required pair-wise DOAs may be calculated using Time Delay Estimations (TDEs), which may in turn be calculated using cross-correlation, making the algorithm suitable for wide-band signals. No a priori knowledge of the true Sound Source Location (SSL) is required. Simulations show that the algorithm is robust against noise in the input data. An average ratio of approximately 3:1 exists between the input DOA errors and the output DOA error. Field tests with a moving sound source provided DOA estimates with standard deviations between 20.4 and 15.2 degrees.