Minimax filters for microphone arrays

Conventionally, minimax spatial/spectral filters for microphone arrays are designed by first discretizing the spatial and frequency domains into a finite number of grid points and then performing the optimization over these points. The drawback with this approach is that the response of the spatial/spectral filters in between the grid points can be poor. More recently, an approach that performs the minimax design over the continuum of points in the decision space has appeared in the literature. In this brief, we describe an approach to solving this continuous decision space design problem that is numerically more elegant and efficient. The effectiveness of the new method is illustrated by a numerical example.