Distortionless Beamforming Optimized With $\ell _1$ -Norm Minimization.

We propose a beamforming method that minimizes the $\ell _1$ norm of a beamformer output vector under the same distortionless constraint as that of the conventional minimum power distortionless response (MPDR) beamformer. Using the $\ell _1$ norm 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 $T_{60}$ = 300 ms in a simulation. [ABSTRACT FROM AUTHOR]