This paper presents an exact formulation of Stochastic or Unconditional Maximum Likelihood (UML) estimation for directions-of-arrival (DOA) finding. In the previous formulation of UML estimation, an important condition is missing. That is the non-negative definiteness of the covariance matrix of signal components without additive noises. Because of the lack of the important condition, inadequat...

A procedure to synthesize asymmetrically shaped beam patterns is developed for planar antenna arrays. As it is based on the quasianalytical method of collapsed distributions, themain advantage of this procedure is the ability to realize a shaped (null-free) region with very low ripple. Smooth and asymmetrically shaped regions can be used for Direction-of-Arrival estimation and subsequently for ...

In wireless communication scenarios, local scatterers in the vicinity of the mobile sources cause angular spreading. As a result, the spatial signatures will not belong to the conventional array manifold parameterized by direction of arrival (DOA) alone. In this paper, a parameterized model for spatial signatures applicable in scenarios with local scattering is presented. Several algorithms tha...

We propose a new method that detects conversation groups when multi-conversation groups exist simultaneously. The proposed method uses hands-free microphone arrays without wearable microphones. It has two main features: (a) We integrate a conventional turn taking-based conversation detection method with Direction of Arrival (DOA) estimation-based Voice Activity Detection (VAD). (b) The proposed...

This paper addresses practical issues for the implementation of sequential Monte Carlo sampling schemes, also known as particle ltering, for application to tracking problems. The discussion focusses on ways to improve on previous resampling schemes, resulting in signi cantly improved performance. These conclusions are demonstrated and supported by examples of application of the particle lter to...

Sparse reconstruction methods have been used extensively for source localization over uniform linear arrays and circular arrays. In this paper a sparse reconstruction method for speech source localization using partial dictionaries over a spherical microphone array is proposed. The source localization method proposed in this work addresses two important research issues. It formulates the source...

This paper presents crystal-MUSIC, a method for DOA estimation of multiple sources in the presence of diffuse noise. MUSIC is well known as a method for the estimation of the DOAs of multiple sources but is not very robust to diffuse noise from many directions, because the covariance structure of such noise is not spherical. Our method makes it possible for MUSIC to accurately estimate the DOAs...

Direction-of-arrival (DOA) estimation of coherent sources is a significant problem in impulsive noise environments. In this paper, a robust estimation algorithm which combines the ideas of spatial smoothing (SS) and infinity-norm normalization (INF) is presented, referred to as INF-SSR. The proposed algorithm exploits the Root– MUSIC technique to computer the DOA estimates, thus avoiding the pe...

Multiple sound source localization remains a challenging issue due to the interaction between sources. Although traditional approaches can locate multiple sources effectively, most of them require the number of sound sources as a priori knowledge. However, the number of sound sources is generally unknown in practical applications. To overcome this problem, a spatial principal eigenvector based ...

This paper presents a new method for estimating the directions of source signals. We assume a situation in which multiple source signals are mixed in a reverberant condition and observed at several sensors. The new method is based on independent component analysis, which separates mixed signals into original source signals. It can be applied where the number of sources is equal to the number of...