A Directional-Derivative-Constrained Method for Continuously Steerable Differential Beamformers with Uniform Circular Arrays

TL;DR

This paper introduces a novel framework for designing differential beamformers with directional derivative constraints, enabling continuous steering and improved robustness in circular array-based acoustic signal acquisition.

Contribution

It proposes a new method that incorporates derivative constraints to achieve continuously steerable and robust differential beamformers for circular arrays.

Findings

Produces continuously steerable beampatterns

Enhances steering flexibility and robustness

Improves beampattern design intuitiveness

Abstract

Differential microphone arrays offer a promising solution for far-field acoustic signal acquisition due to their high spatial directivity and compact array structure. A key challenge lies in designing differential beamformers that are continuously steerable and capable of enhancing target signals arriving from arbitrary directions. This paper studies the design of differential beamformers for circular arrays and proposes a novel framework that incorporates directional derivative constraints. By constraining the first-order derivatives of the beampattern at the desired steering direction to zero and assigning suitable values to higher-order derivatives, the beamformer is ensured to achieve its maximum response in the target direction and provide sufficient beam steering. This approach not only improves steering flexibility but also enables a more intuitive and robust beampattern design. Simulation results demonstrate that the proposed method produces continuously steerable beampatterns.