April 2013
Intermediate
536 pages
15h 39m
English
8
Frequency-Domain Array Beamformers for Noise Reduction
This chapter gives a fresh perspective on beamforming in the frequency domain with a microphone array. This is also an overview of the most important array beamformers that can be found in the literature, where several of them are easy to implement in the context of speech enhancement. To simplify the presentation, we focus on the noise reduction problem only. The generalization of the concepts exposed here can be extended, with some efforts, to the problem of joint reverberation and noise reduction.
8.1 Signal Model and Problem Formulation
We consider a uniform linear sensor array1 consisting of 
omnidrectional microphones and for which the distance between two successive sensors is equal to 
. In a general way, the received signals at the frequency index 
are expressed as [1, 2]
where 
is the mth microphone signal, 
is the unknown ...
