Title
Fundamental Approaches to Robust Differential Beamforming With High Directivity Factors
Abstract
Differential beamforming, which measures the spatial derivatives of the acoustic pressure field, can be used in a wide range of small devices that require high-fidelity sound and speech acquisition as it can achieve frequency-invariant spatial responses with high directivity factors (DFs). The most challenging problem in the design of any differential beamformer is how to achieve the maximum possible DF while maintaining a proper level of robustness for practical usage. This paper is devoted to dealing with this challenging problem. It presents a study on theory and methods to achieve the optimal and fundamental compromise between the white noise gain (WNG), which quantifies how robust is the beamformer, and the DF in differential beamforming. The major contributions of this work are as follows. 1) We show and prove that any null constrained fixed beamformer can be decomposed as the sum of two orthogonal filters, i.e., the maximum WNG (MWNG) beamformer and a reduced-rank one. Based on this decomposition, we develop three kinds of differential beamformers from the WNG perspective, which can achieve a flexible and optimal compromise between DF and WNG. 2) We show that a transformed null constrained beamformer can also be decomposed as the sum of two orthogonal filters, i.e., the transformed maximum DF (MDF) beamformer and another reduced-rank one. Based on this decomposition, we also develop three kinds of differential beamformers, which can obtain the desired level of DF while using the rest of the degrees of freedom to maximize the WNG.
Year
DOI
Venue
2022
10.1109/TASLP.2022.3209935
IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING
Keywords
DocType
Volume
Array signal processing, Sensors, White noise, Acoustics, Sensor arrays, Microphone arrays, Robustness, Beampattern, differential beamforming, directivity factor, microphone arrays, quadratic eigenvalue problem, robust beamforming, white noise gain
Journal
30
Issue
ISSN
Citations 
1
2329-9290
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Gongping Huang17613.39
Jacob Benesty21386136.42
Jingdong Chen31460128.79