An enhanced beamsteering algorithm based on MVDR for a multi-channel parametric array loudspeaker array

Yunxi Zhu, Yankai Zhang, Fengyi Fan, Wenyao Ma, Liwen Qin, Zheng Kuang, Ming Wu, Jun Yang*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A multi-channel parametric array loudspeaker (PAL) array can steer an audio beam using a digital signal processing technique. However, it faces the challenge posed by grating lobes in the ultrasonic radiation pattern, which leads to unwanted sidelobes in the steering audio beam when the Nyquist criterion is not satisfied due to short ultrasonic wavelengths. As a result, the audio beam not only fails to steer in the desired direction but also loses its inherent advantage of high directivity when using a beamsteer with a delay-and-sum (DAS) structure. This work proposes an enhanced beamsteering algorithm to suppress the sidelobes by optimizing the channel weight coefficients. The nonlinear optimization problem is transformed into a linear expression, making the minimum-variance-distortionless-response (MVDR) algorithm applicable. Both simulations and experiments validate the effective suppression of sidelobes and the mitigation of sound fuzziness within the range from the sidelobe to the mainlobe. The audio beam successfully steers in the desired direction and maintains a high directivity. However, the performance of the algorithm deteriorates at high audio frequencies due to the inherent physical limitations of wave interference in sound field control strategies.

Original languageEnglish
Article number118768
JournalJournal of Sound and Vibration
Volume595
DOIs
Publication statusPublished - Jan 20 2025
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2024 Elsevier Ltd

ASJC Scopus Subject Areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Acoustics and Ultrasonics
  • Mechanical Engineering

Keywords

  • Beamsteering
  • Directional audio beam
  • MVDR
  • Nonlinear sound field control
  • Parametric array loudspeaker
  • Sidelobe suppression

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