A Note on Wavelet-Based Estimator of the Hurst Parameter

• Published in: Entropy (Basel, Switzerland) Vol. 22; no. 3; p. 349
• Main Author: Wu, Liang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.03.2020; MDPI
• Subjects: Bias; Brownian motion; Computer simulation; Dependence; Empirical analysis; Fractals; fractional brownian motion; hurst parameter; long-range dependence; Mathematical models; Methods; Normal distribution; Parameter estimation; Regression analysis; Self-similarity; Signal processing; Simulation; Studies; Trends; Wavelet analysis; Wavelet transforms; Hurst parameter; fractional Brownian motion; long-range dependence; wavelet analysis
• ISSN: 1099-4300; 1099-4300
• DOI: 10.3390/e22030349

The signals in numerous fields usually have scaling behaviors (long-range dependence and self-similarity) which is characterized by the Hurst parameter H. Fractal Brownian motion (FBM) plays an important role in modeling signals with self-similarity and long-range dependence. Wavelet analysis is a common method for signal processing, and has been used for estimation of Hurst parameter. This paper conducts a detailed numerical simulation study in the case of FBM on the selection of parameters and the empirical bias in the wavelet-based estimator which have not been studied comprehensively in previous studies, especially for the empirical bias. The results show that the empirical bias is due to the initialization errors caused by discrete sampling, and is not related to simulation methods. When choosing an appropriate orthogonal compact supported wavelet, the empirical bias is almost not related to the inaccurate bias correction caused by correlations of wavelet coefficients. The latter two causes are studied via comparison of estimators and comparison of simulation methods. These results could be a reference for future studies and applications in the scaling behavior of signals. Some preliminary results of this study have provided a reference for my previous studies.