中文摘要：

该文给出了信号变化度的定义，并证明了独立源信号的线性混合信号（非零信号）的变化度介于源信号中的最小变化度和最大变化度之间。在此性质的基础上，给出了一种线性混合信号盲提取算法。该算法首先利用广义特征值理论从混合信号中提取出一个源信号，然后采用消源方法剔出混合信号中该源信号分量，重复这一过程，逐一提取出所有的源信号。该算法计算简单，仿真结果表明该算法是有效的，并具有很好的性能。

英文摘要：

In this paper, a measure of signal variability is defined. Given any set of statistically independent source signals, it is proved here that a linear mixture of those signals has the following property： the signal variability of any signal mixture is greater than （or equal to） minimal that of its component source signals, and is less than （or equal to） maximal that of its component source signals. Based on the property, an algorithm for linear blind signal extraction is proposed. In the proposed algorithm, the source signal is extracted one by one by using generalized eigenvalue theory and deflation approach. The presented algorithm has less computations. Simulation results illustrate the efficiency and the good performance of the algorithm.