An alternative implementation of quadratically constrained broadband beamformers

Abstract

This paper presents an alternative constraint system for implementing the quadratically constrained broadband beamformers. The resulting system involves a linear equality constraint and a quadratic inequality constraint. It offers some savings in the computation load as compared to the original problem in the sense that the quadratic constraint will be used as and when necessary. The relationship that the new constraint system has to other constraint systems is explored. It is shown that the constraint system with linear constraint is equivalent to the CCMP method and the constraint system with linear and quadratic constraints is equivalent to the improved CCMP method. The alternative formulation provides several insights into the CCMP method and the improved CCMP method.