谐波和间谐波参数估计的新方法

New Estimation Method for Harmonic and Inter-Harmonic Parameters

为解决谐波和间谐波参数估计受噪声影响的难题,从被检测信号噪声的基本特性出发,提出了一种基于现代互谱、总体最小二乘、旋转不变参数估计和改进普罗尼技术的谐波和间谐波参数估计新方法.该方法采用互谱技术处理不同采样序列的互相关矩阵;根据不同时刻白噪声相互独立的原理划分信号子空间和噪声子空间,并结合总体最小二乘与旋转不变参数估计判定被检测信号的频率;最后,根据白噪声均值为0的特性,采用改进普罗尼技术估计信号分量的幅值和初始相角.仿真结果表明,该方法在低信噪比环境下可检测出多个子信号,且频率的相对误差均小于0.4%,而耗时仅0.058 s,具有良好的估计精度和估计效率.

In order to analyze the effect of noise signals on the estimation of harmonic and inter-harmonic parameters,a new method was proposed on the basis of the essential property of noise information and the several useful strategies including the modern cross-spectrum,total least square,ESPRIT（estimation of signal parameters via rotational invariance） and improved Prony techniques.In this method,the cross-spectrum technique is used to deal with the cross-correlation matrix of different sampled signal sequences,and signal and noise subspaces are identified validly with the help of the independent principle of white noise at different times.And then the frequencies of signal components can be extracted directly by combining the total least square technique with the ESPRIT technique.Finally,based on the estimated frequency of every signal component and the characteristic of zero average value of noise signals,the magnitude and initial phase of the signal components are obtained by using the improved Prony technique.The results show that conditioned upon low signal-to-noise ratio,the proposed method can distinguish more sub-signals and the relative errors of frequencies are less than 0.4% with merely time consumption of 0.058 s,characterizing a high estimation accuracy and efficiency.