一种基于非对称窗的相位差法  

Phase difference method based on asymmetrical windows

作　　者：罗久飞[1] 谢志江[1] 熊鹰[1] 

机构地区：[1]重庆大学机械工程学院,重庆400044

出　　处：《振动与冲击》2015年第18期147-153,共7页Journal of Vibration and Shock

摘　　要：提出一种新的相位差法,用来校正离散频谱中频率、相位和幅值的误差。由于经典窗函数的对称性,它们具有恒定的时延和相同的相位响应。解除窗函数的对称性限制,可以引入具有可变时延和不同相位响应的非对称窗函数。建立在非对称窗的可变相位基础之上的相位差法可以克服传统方法的一些固有缺点。仿真表明通过选择合适的窗函数,对相邻很近的频率成分,该方法校正也能保证精确的结果。该方法还可以从根本上避免最高谱线定位错误带来的误差。对带有加性高斯白噪声的理论信号分析,结果显示直接基于非对称窗的校正方法与传统方法的抗噪性能相似。另外,将传统方法中的对称窗替换为非对称窗可以提高算法的抗噪性能。An improved method, phase difference method based on asymmetric windows, was proposed aiming at correcting the errors of parameters in discrete spectrum. Several examples simulations show that with proper choice of asymmetric windows, the new method can correct the errors of frequency components located in less than five DFT bins. And it can also avoid the errors induced by the mistaken location of right spectral line. The corrected results of a theoretical signal involved in different noise conditions also exhibit a stronger robustness against additive noise when the symmetric windows are replaced with asymmetric windows.

关 键 词：窗函数 线性相位 频谱校正 相位差法 

分 类 号：TN911.6[电子电信—通信与信息系统]