随机信号包络的统计特性与包络谱的计算

对随机信号的分析是研究、处理各种随机振动问题的必要步骤。各种随机信号的包络的计算统计特性和包络谱的计算已屡见于各方面的研究及应用领域。本文先综述有关研究结果，并就一些文献中关于包络谱实际计算结果里的一个问题提出质疑，指出很可能是因不恰当地运用了某种谱估计方法处理的计算所致。

STATISICAL CHARACTERISTICS OF THE ENVELOPE OF A RANDOM SIGNAL AND COMPUTATION OF THE ENVELOPE SPECTRUM

It is required to analyze random signals in treating many Stochastic vibration problems. Various examples of computation for the random envelope and its statistical characteristics, especially the envelope spectrum, are involved in many applied fields. After having reviewed general statistical properties of the random envelope, this paper concentrates on one question in computing the envelope spectrum. Our result, both in theory and in numerical examples of computation, shows that the envelope spectrum reaches maximum value at zero frequency, which is different from ones in some previous literatures. It is pointed out that the previous results are most likely produced by using the method for spectral estimation in an inappropriate way.