Time-delay estimation using the Wigner-Ville distribution

TL;DR

This paper introduces a time-delay estimation method using the Wigner-Ville Distribution, demonstrating improved accuracy and lower uncertainty over traditional methods, especially in energetic frequency bands.

Contribution

The paper proposes a novel time-delay estimation approach based on the Wigner-Ville Distribution, offering better resolution and accuracy than wavelet-based methods.

Findings

WVD provides more accurate delay estimates in energetic frequency bands.

The method achieves lower uncertainty compared to traditional approaches.

Applicable to nonstationary signals in wave-physics scenarios.

Abstract

Accurately calculating time delays between signals is pivotal in many modern physics applications. One approach to estimating these delays is computing the cross-spectrum in the time-frequency domain. Linear time-frequency representations, such as the continuous wavelet transform (CWT), are widely used to construct these cross-spectra. However, it is well known that the frequency resolution is inherently limited by the localized nature of the convolving wavelet. Moreover, the functional form of the CWT cross-spectrum is not a proper correlation measure and typically requires post-processing smoothing. Conversely, quadratic representations achieve joint time-frequency resolution approaching the Gabor-Heisenberg limit while also providing an adequate measure of similarity between the signals. Motivated by these advantages, we propose a time-delay estimation method based on the Wigner-Ville Distribution (WVD). Considering nonstationary signals arising from two typical wave-physics scenarios, we show that the WVD yields more accurate time-delay estimates with lower uncertainty, particularly in the most energetic frequency bands.