【摘要】 频谱泄漏和栅栏效应是影响衰减信号离散傅里叶变换精度的主要因素。为了提高多频衰减信号离散傅里叶变换频谱参数的校正精度,提出一种加窗两点矢量插值校正算法。对信号加M阶余弦窗并计算加窗后信号的离散傅里叶变换,利用真实频率附近的两根谱线的矢量比建立方程,通过求解方程获得频率偏移量和衰减因子,利用上述获得的两个参数计算出信号的频率、幅值和相位。余弦窗的最大旁瓣衰减特性能有效的降低频谱泄漏的影响,两点矢量频域插值可以消除栅栏效应,两者结合极大地提高了算法的参数校正精度。仿真和试验结果表明,算法具有较高的参数校正精度和稳定性,且计算效率较高,适用于实时处理及对计算资源要求苛刻的场合,为多频衰减信号的特征提取提供了一种可选的方法。更多还原

【Abstract】 The major parameter estimation error source for discrete Fourier transform are spectrum leakage and picket fence effect. A weighted two points vector interpolation algorithm based on Rife-Vincent window for improving the estimation accuracy of parameters for the multi-frequency damped signals is presented, where the signals are weighted by M-order cosine window family before the discrete Fourier transform and the equations with nuknown of frequency deviation and decay factor is established by the ration of two adjacent spectral lines near the real frequency position. The frequencies, amplitudes and phases are calculated by the frequency deviation solved from the above equation. The cosine window family with the characteristic of maximum sidelobe decay can essentially remove the spectral leakage and two point vector interpolation will cope with the problem of the picket fence. To combine the merits of the above two method can effectively increase the accuracy. The simulation and test results show that the proposed algorithm has a higher estimate accuracy and steady estimates. The higher computational efficiency and lower memory demand are suggested especially for poor computing resource situations. It also can be used as an optional method for the features extraction of the multi-frequency damped signals.更多还原