A fractional Fourier transform (FrFT) based estimation method is introduced in this paper to analyze the long range dependence (LRD) in time series. The degree of LRD can be characterized by the Hurst parameter. The FrFTbased estimation of Hu

hurst指数，用来预测将来的走势与现在的走势是否一致或者相反。-hurst index, used to predict the future trend is inconsistent or contrary to the current trend.