比值法的频率估计精度分析  

Accuracy analysis for frequency estimation of amplitude ratio method

作　　者：柏林[1] 董鹏飞[1] 刘小峰[1] 徐冠基[1] 

机构地区：[1]重庆大学机械传动国家重点实验室,重庆400044

出　　处：《重庆大学学报（自然科学版）》2010年第10期7-13,31,共8页Journal of Chongqing University

基　　金：国家863计划资助项目(2008AA042408);重庆市自然科学基金资助项目(CSTC;2009BB3194;2009BB0355);重庆大学211项目(S-09106)

摘　　要：针对快速傅里叶变换(FFT)中的频谱泄漏现象,对目前工程信号处理中广泛采用的多种比值频率估计算法进行了系统深入的研究。首先综合论述了各种比值频率校正方法的原理、特点,具体分析了信噪比、采样序列含有的波数以及无量纲频率偏移量对各种方法频率估计精度的影响。然后,采用仿真实验对各种频率校正方法的性能进行了具体的分析与比较。实验结果表明,频率估计精度存在下限,并不总是随着信噪比的提高而提高;当信号含有的波数较少时,各种方法频率估计的精度较差,对于大部分方法,增加波数能够显著提高其精度,当波数较多时,各方法的精度较好且稳定;加窗能提高Rife-Jane方法和Vetterling方法的精度。最后结合具体的工程环境,给出了频率校正方法的选择规律和原则。Aiming at the spectrum leakage that exists in fast Fourier transform （FFT）,several ratio frequency estimation algorithms that widely used by engineering signal processing are deeply studied. Firstly,the principles and features of these algorithms are introduced,and the influences of three parameters on frequency estimation accuracy are concretely analyzed. These parameters are signal to noise （SNR）,cycles covered in record and the distance from the DFT output peak to the true frequency in bin widths. Then,related simulations are carried out to analyze and compare the performance of these frequency correction methods. The simulation results show that the frequency estimation accuracy has lower limit. When the number of the waves in the tone is small,the accuracy of these methods is poor,but can be improved observably by increasing the waves for the most methods. When the number of the waves in the tone is large,most methods have high and stable accuracy. The performance of the Rife-Jane＇s method and Vetterling＇s method can be improved by using Hanning-tapered data. Finally,considering specific engineering environment,some rules and principles about how to choose appropriate algorithm are provided.

关 键 词：频率估计 比值法 动平衡 校正精度 

分 类 号：TN911.6[电子电信—通信与信息系统]