Linearly Constrained Minimum Variance Beamforming
The concept of “beamforming” refers to multichannel signal processing techniques that enhance the acoustic signals coming from a particular a priori known position, while reducing the signals coming from other directions. A number of beamforming techniques exist, a review of which may be found in . In this chapter, we introduce linearly constrained minimum variance (LCMV) beamformers, which are widely used in acoustic array processing. The class of the LCMV beamformers is general enough to form a common framework to design beamforming algorithms for various physical setups.
Section 3.1 defines the LCMV beamforming principle. Section 3.2 provides the generalized sidelobe canceler (GSC) as an alternative formulation of the LCMV beamformer which can be implemented more efficiently. Section 3.3 shows how to apply the GSC to distributed and compact microphone arrays. Section 3.4 discusses the practical limitations of LCMV beamforming in reverberant environments.
KeywordsTarget Signal Interference Canceler Spatial Response Microphone Array Unit Impulse
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