Fast Cross-Correlation for TDoA Estimation on Small Aperture Microphone Arrays

TL;DR

This paper presents the Fast Cross-Correlation (FCC) method for TDoA estimation that significantly speeds up computation on small microphone arrays, enabling real-time processing and longer battery life on embedded hardware.

Contribution

The paper introduces FCC, a novel low-rank decomposition-based method that accelerates TDoA estimation while maintaining accuracy, outperforming FFT-based GCC methods in speed.

Findings

FCC reduces computational flops by 4.5 times.

FCC speeds up execution by 3.5 to 8.3 times on embedded hardware.

FCC maintains TDoA accuracy comparable to state-of-the-art methods.

Abstract

This paper introduces the Fast Cross-Correlation (FCC) method for Time Difference of Arrival (TDoA) Estimation for pairs of microphones on a small aperture microphone array. FCC relies on low-rank decomposition and exploits symmetry in even and odd bases to speed up computation while preserving TDoA accuracy. FCC reduces the number of flops by a factor of 4.5 and the execution speed by factors between 3.5 and 8.3 on embedded hardware, compared to the state-of-the-art Generalized Cross-Correlation (GCC) method that relies on the Fast Fourier Transform (FFT). This improvement can provide portable microphone arrays with extended battery life and allow real-time processing on low-cost hardware.