Numerical near field optimization of a non-uniform sub-band filter-and-sum beamformer

Abstract

A novel near field filter-and-sum beamformer using non uniform frequency sub-bands is presented. The concept is based on numerical optimization of the reception characteristic of the microphone array. In order to improve the reception characteristic over frequency and space, a non uniform filterbank is utilized to subdivide the frequency range. Individual optimization processes for each sub-band result in a clearly improved reception characteristic. The new system is able to closely approximate a target (independently of the frequency) which can be defined according to the application.