关键词: 白噪声, 能量重心, 频率估计, 频谱分析

Abstract: The influence of noise on frequency estimation accuracy of energy barycenter correction method for discrete spectrum is studied. The theoretical formula for frequency estimation error is deduced by applying energy barycenter correction method for discrete spectrum in the presence of Gaussian white noise, which is multiplied by a symmetrical window function. The theoretical error is analyzed for either right or wrong maximal spectrum line searched and the reasons for the frequency estimation error increasing under some conditions are presented. Measures are proposed that will be chose for the threshold phase difference between two spectrum lines is taken as the threshold to be the basis for selecting three or four spectrum lines to carry out the correction, so as to improve the accuracy of frequency estimation. Simulation analysis of discrete spectrum multiplied by Hanning window function is finally performed, which is consistent with theoretical derivation and verifies the correctness thereof, the results demonstrate that there is high frequency estimation accuracy even if the signal is badly influenced by strong noise, and show that the improved energy barycenter correction method for discrete spectrum has higher anti-noise performance, which expands the application scope of energy barycenter correction method.

Key words: Energy barycenter, Frequency estimation, Spectrum correction, White noise