Block-sparse beamforming for spatially extended sources in a Bayesian formulation

TitleBlock-sparse beamforming for spatially extended sources in a Bayesian formulation
Publication TypeJournal Article
Year of Publication2016
AuthorsXenaki A., Fernandez-Grande E., Gerstoft P
JournalJournal of the Acoustical Society of America
Date Published2016/09
Type of ArticleArticle
ISBN Number0001-4966
Accession NumberWOS:000386932500042
Keywordslasso; regularization; sensor arrays; signal reconstruction; variable selection

Direction-of-arrival (DOA) estimation refers to the localization of sound sources on an angular grid from noisy measurements of the associated wavefield with an array of sensors. For accurate localization, the number of angular look-directions is much larger than the number of sensors, hence, the problem is underdetermined and requires regularization. Traditional methods use an l(2)-norm regularizer, which promotes minimum-power (smooth) solutions, while regularizing with l(1)-norm promotes sparsity. Sparse signal reconstruction improves the resolution in DOA estimation in the presence of a few point sources, but cannot capture spatially extended sources. The DOA estimation problem is formulated in a Bayesian framework where regularization is imposed through prior information on the source spatial distribution which is then reconstructed as the maximum a posteriori estimate. A composite prior is introduced, which simultaneously promotes a piecewise constant profile and sparsity in the solution. Simulations and experimental measurements show that this choice of regularization provides high-resolution DOA estimation in a general framework, i.e., in the presence of spatially extended sources. (C) 2016 Acoustical Society of America.

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