中文摘要：

研究噪声对离散频谱能量重心法的频率校正精度的影响，推导了在高斯白噪声背景下用能量重心法对加对称窗的离散频谱进行校正的频率误差理论公式，分析找错和找对最大值谱线情况下的理论误差和某些情况下校正误差较大的原因，为了提高能量重心校正法的频率校正精度，提出用谱线间相位差为阈值作为选择用3条或4条谱线进行校正依据的改进措施。通过对加Hanning窗的离散频谱进行计算机仿真计算，结果表明在大噪声背景下改进的能量重心校正法有很高的频率校正精度，与理论推导十分吻合，验证了理论推导的正确性，表明改进后的能量重心法具有更高的抗噪性能，扩大了能量重心校正法的工程应用范围。

英文摘要：

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 Harming 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.