功率谱平均及其估值的置信区间

Power Spectrum Average and the Confidence Interval of Its Estimation

信号源的相位噪声是一个随机过程,通常可用概率密度数函、自相关函数及功率谱等参量来作统计描述,其中尤以功率谱更被广泛采用。它是一个频域量度,以频谱分析仪作为测量基础。我们建立了一套双源法自动相位噪声测量系统,用HP3582A数字式频谱分析仪作为终端设备,并利用功率谱平均法来降低测量不确定度。本文着重分析这种方法所得功率谱估值的概率分布,以及在给定置信度时,置信区间与功率谱平均数的关系。

The phase noise of the signal source is a random process. Usually it is statistically described by means of probability density func- tion, autocorrelation function, and power spectrum. Among them power spectrum is used more widely. It is a frequency-domain parameter and measured with frequency spectrum analyzer. We have set up an automa- tic phase noise measurement system using the method of double sources. This system uses HP3582A digital frequency spectrum analyzer as its termi- nal equipment, and power spectrum average method has been used to dec- rease the uncertainity of measurement. In this paper we emphatically analyze the probability distribution of the power spectrum estimation obta- ined by this method, and give the relationship between confidence inter- val and power spectrum average for the given confidence.