基于幅频谱估计系统时域响应的改进方法研究

Improved method for estimating time domain response based on the magnitude frequency spectrum

为弥补常规最小相位法估计的不足,提出了一种向量拟合法与最小相位法相结合的由幅频谱估计时域响应的改进方法,并通过无限大平面材料和暗箱窗口法测试的仿真数据检验了该方法的可行性.与常规的最小相位估计法相比,该方法减小了因反复进行时频转换而产生的数值误差,受噪声影响小、重复性好.但是对于非最小相位系统,该方法的估计结果会有一定误差.改进的方法可以用来替代常规最小相位估计法.

In order to remedy the method of conventional minimum phase estimation,an improved method combining of vector fitting and minimum phase was proposed for estimating the time-domain response of the system using the data of the amplitude spectrum in this paper.The feasibility of the improved method was verified through simulaion data of infinite plane materials and windowed semi-anechonic cabinet.Compared with the method of conventional minimum phase estimation,the improved method reduces the conversion number of time-domain to frequency-domain and the cumulative error caused by using repeatedly fast fourier transform algorithm.The improved method is not sensitive to noise and gets a good stability.But for nonminimum phase systems,estimation results with the improved method have some error.In summary,the improved method can be used to replace the method of conventional minimum-phase estimation.