Broadband array processing using subband techniques

In this paper, we consider array processing techniques for broadband signals. The optimisation techniques and associated performance results correspond to steerable but fixed beam microphone arrays, to be used in a variety of applications, both in free-space and in reverberant conditions. The proposed arrays maximize the energy concentration around the desired look directions, minimize reverberant disturbance, cancel individual interferers, and control the amount of signal distortion. Optimization criteria for array subband processing are also given. The uniformly spaced subband and the non-uniformly spaced subband using quadrature mirror filter approaches are treated. Finally, various simulation results for free-space and reverberant conditions are presented to demonstrate the usefulness of this class of microphone array, as well as the feasibility of quadrature mirror filter-based subband processing