Broadband Adaptive Beamforming Base on the Sparse Constraint and Spatial Response Variation Constraint

Regarding the problem of the high sidelobe level and output SINR performance degradation of conventional broadband adaptive beamformer due to interference suppression and over-constraints with a less number of degrees of freedom (DOF) for interference suppression, a novel broadband beamformer with low sidelobe level and high array gain is proposed by employing sparse constraint and the spatial response variation constraint (SRV). To suppress the sidelobe level of adaptive beamforming, sparse constraint on the beam pattern is added to the narrowband minimum variance distortionless response (MVDR) beamformer.Then the algorithm is extended to broadband adaptive beamforming by the spatial response variation constraint with low computational complexity and high output signal to interference noise ratio (SINR).Moreover, lower Peak sidelobe lever (PSL) and well effect of interference suppression can be achieved in comparison with traditional methods. The effectiveness of this new method is illustrated by a few numerical examples.