Design of planar differential microphone arrays with fractional orders

Huang G, Chen J, Benesty J (2020)

Publication Type: Journal article

Publication year: 2020

Journal

IEEE/ACM Transactions on Audio, Speech and Language Processing Institute of Electrical and Electronics Engineers (IEEE)

Book Volume: 28

Pages Range: 116-130

Article Number: 8880528

DOI: 10.1109/TASLP.2019.2949219

Abstract

Differential microphone arrays (DMAs) often encounter white noise amplification, especially at low frequencies. If the array geometry and the number of microphones are fixed, one can improve the white noise amplification problem by reducing the DMA order. With the existing differential beamforming methods, the DMA order can only be a positive integer number. Consequently, with a specified beampattern (or a kind of beampattern), reducing this order may easily lead to over compensation of the white noise gain (WNG) and too much reduction of the directivity factor (DF), which is not optimal. To deal with this problem, we present in this article a general approach to the design of DMAs with fractional orders. The major contributions of this article include but are not limited to: 1) we first define a directivity pattern that can achieve a continuous compromise between the pattern corresponding to the maximum DMA order and the omnidirectional pattern; 2) by approximating the beamformer's beampattern with the Jacobi-Anger expansion, we present a method to find the proper differential beamforming filter so that its beampattern matches closely the target directivity pattern of fractional orders; and 3) we show how to determine analytically the proper fractional order of the DMA with a given target beampattern when either the value of the DF or WNG is specified, which is useful in practice to achieve the desired beampattern and spatial gain while maintaining the robustness of the DMA system.

Authors with CRIS profile

Gongping Huang

Involved external institutions

Northwestern Polytechnical University / 西北工业大学 (NPU/NWPU) CN China (CN) Université Laval (UL) CA Canada (CA)

How to cite

APA:

Huang, G., Chen, J., & Benesty, J. (2020). Design of planar differential microphone arrays with fractional orders. IEEE/ACM Transactions on Audio, Speech and Language Processing, 28, 116-130. https://doi.org/10.1109/TASLP.2019.2949219

MLA:

Huang, Gongping, Jingdong Chen, and Jacob Benesty. "Design of planar differential microphone arrays with fractional orders." IEEE/ACM Transactions on Audio, Speech and Language Processing 28 (2020): 116-130.

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