Decorrelation for adaptive beamforming applied to arbitrarily sampled spherical microphone arrays

Correlated signals lead to signal cancellation in adaptive beamformers applied to microphone arrays. This is commonly counteracted by spatial smoothing. Unfortunately, spatial smoothing can only be used with array geometries consisting of identical, shifted subarrays, making it unsuitable for spherical arrays in general. We suggest a transformation that makes spatial smoothing applicable to any well-sampled spherical array, and we show results for the case of Minimum Variance Distortionless Response (MVDR) beamforming.