Distortionless Beamforming Optimized With $\ell _1$ -Norm Minimization
Satoru Emura, Shoko Araki, Tomohiro Nakatani, Noboru Harada · IEEE Signal Processing Letters · 2018
We propose beamforming method that minimizes the ℓ1norm of a beamformer output vector under the same distortionless constraint as that of the conventional minimum power distortionless response (MPDR) beamformer. Using the ℓ1norm makes the beamformer output sparse. This leads to reducing the residual elements of the interference signal. In addition, the sensitivity of the proposed beamformer can be controlled by adding a norm constraint as in the MPDR beamformer. The proposed method improved the signal-to-interference-noise ratio by 7 dB from that of the MPDR beamformer for reverberation time T60= 300 ms in a simulation.