FDME-RATE: Frequency-Domain-Based Multipath Extraction for Robust Acoustic TOA Estimation

High-accuracy time of arrival (TOA) estimation is essential for indoor acoustic localization, but traditional TOA estimation methods often fail to obtain accurate and robust TOA estimation performance due to severe multipath challenges, such as peak extraction by general cross correlation (GCC). To address the problem, this article presents a novel acoustic TOA estimation technique called FDME-RATE, a high-accuracy acoustic ranging system. The proposed method utilizes GCC to determine the coarse signal arrival time, followed by an enhanced frequency modulated continuous wave (FMCW) technique to convert the various arrival paths into distinct frequencies within the spectrum. In addition, we employ an adaptive multiple signal classification (AMUSIC) algorithm to achieve high-resolution TOA estimation. Through simulations and experiments conducted in a reverberant corridor, the results indicate that our method achieves an average TOA ranging error of just 0.16 and 0.19 m at the 95% confidence level across a 30-m span. Within a 20-m range, there is only a centimeter-level error. Additionally, in non line-of-sight (NLOS) scenarios, our proposed method further enhances TOA-based ranging accuracy by an additional 0.3 m over the same distance. The experimental results also demonstrate that our method outperforms traditional methods and recent research in terms of both estimation accuracy and robustness.