单通道信号分离一直是信号处理领域中的重要问题,是被许多学者广泛研究的热点与难点问题之一。本文提出一种以时间自相关函数作为目标函数的最优化分离方法。先使用小波模极大值法来估计出迭代初始值与源信号的时间自相关函数,然后得到的最优解就是对待分离信号的估计。实验结果表明,该方法能够较好地应用于诱发电位信号的单通道单次提取。
The single channel signal separation is an important issue in signal processing field and has been widely researched in recent years.Its main purpose is to separate the signals of interest from the single channel observations.And one of its typical applications is the single channel extraction of evoked potentials.In this paper,we proposed an optimization method whose objective function is based on the temporal autocorrelation function of the underlying signal.The initial value of the optimization and the temporal autocorrelation were estimated by using the wavelet transform modulus maxima method.This approach was employed to extract the evoked potential signal in single-trial from single channel.The correlation coefficient and the power of the error signal between the extracted result and the underlying signal were respectively 0.98 and 0.25 under 0 dB signal-to-noise ratio conditions,and both the amplitude and latency of the evoked potential signal were accurately extracted.Experimental results showed that the algorithm could extract the evoked potential signal well in single-trial from single channel.