Ktonas P Y, Mallart R
Department of Electrical Engineering, University of Houston, TX 77204-4793.
Electroencephalogr Clin Neurophysiol. 1991 Feb;78(2):105-10. doi: 10.1016/0013-4694(91)90109-h.
A theoretical analysis of the variance for the time delay estimate between two EEG signals, obtained via the phase spectrum method, is presented. Explicit theoretical formulae for the variance are obtained and compared via simulations to experimentally derived results for estimate variability. The variance of the time delay estimate is inversely proportional to the frequency range of interest, to the number of data segments utilized for spectral estimation, and to the coherence between the two EEG signals. The simulations indicate that the formulae can be used even with non-gaussian and relatively narrow-band EEG-like data. A minimum-variance estimate for the time delay is also presented.
本文对通过相位谱方法获得的两个脑电信号之间时延估计的方差进行了理论分析。得到了方差的显式理论公式，并通过模拟将其与实验得出的估计变异性结果进行比较。时延估计的方差与感兴趣的频率范围、用于频谱估计的数据段数量以及两个脑电信号之间的相干性成反比。模拟结果表明，即使对于非高斯且相对窄带的类似脑电的数据，这些公式也可以使用。本文还给出了时延的最小方差估计。
