Direction of Arrival Estimation Based on Delayed-Sum Method in Reverberation Environment
Keiichi Zempo, Tadashi Ebihara, Koichi Mizutani · Japanese Journal of Applied Physics · 2012
Microphone arrays have been used for estimating the direction of arrival (DOA). Owing to intercorrelation among direct and reflected sounds, there are difficulties in estimating DOA using microphone array in highly reverberant environments. The purpose of this research is to estimate the correct DOA in such environments using a small number of microphones with the aid of signal processing. The proposed signal processing uses the relationship that direct signals always arrive earlier than reflected signals. By comparing the delayed-sum signals corresponding to candidate direct signals, the DOA of direct sounds could be determined correctly. We have confirmed the usefulness of the proposed method by conducting several experiments. This proposed method is different from conventional methods because it has high tolerance to the effect of reverberation; it not only enables estimation of DOA but can also be applied to the measurement of the delay of time of flight in reverberant environments.