Direction-of-arrival estimation with blind surface impedance compensation for spherical microphone array.

Area of Science:

• Acoustics
• Signal Processing
• Array Signal Processing

Background:

• Direction-of-arrival (DoA) estimation using spherical microphone arrays relies on mode strength compensation to mitigate array surface impedance effects.
• Mismatches between actual and modeled surface impedances in spherical microphone arrays degrade DoA estimation accuracy.

Purpose of the Study:

• To propose a novel non-parametric beamformer for accurate DoA estimation in the presence of mode strength mismatch.
• To develop a method that reduces the DoA estimation's dependency on array surface impedance characteristics.

Main Methods:

• Utilized a non-parametric beamforming technique.
• Employed a block-diagonal covariance matrix.
• Incorporated order-dependent normalization of spherical harmonic coefficients.

Main Results:

• The proposed method demonstrated robust DoA estimation performance across various surface impedance mismatches.
• The technique significantly reduced the dependency of DoA estimation on the array surface impedance.
• Accurate DoA estimation was achieved even under challenging mode strength mismatch conditions.

Conclusions:

• The developed non-parametric beamformer provides a robust solution for DoA estimation with spherical microphone arrays.
• This approach effectively handles mode strength mismatches, enhancing practical applicability in real-world scenarios.