【作者】 杨君； 袁嗣杰； 吕镜清；

【Author】 YANG Jun~(1,2),YUAN Sijie~1,LV Jingqing~(2,3) 1.TT&C Research Center,the Academy of Equipment Command & Technology,Beijing 101416,China; 2.National Information Control Laboratory,Chengdu 610036,China; 3.Southwest China Research Institute of Electromic Equpiment,Chengdu,610036,China

【机构】 装备指挥技术学院航天测控工程研究中心； 信息综合控制国家重点实验室； 中国电子科技集团公司第二十九研究所；

【摘要】 针对工程中FFT滤波性能难以达到预期效果的问题对FFT的滤波原理进行了深入研究。分析指出了FFT存在频率响应误差,导出了误差项,给出了消除频率响应误差的方法;分析了相位超前现象产生的原因,给出了有效应对措施;最后详细讨论了如何应用频域抽取和补零的方法解除FFT点数与低通原型滤波器长度之间的固定关系,从而能够设计出高性能的低通原型滤波器以进一步提高FFT的滤波质量。更多还原

【Abstract】 Serious study results on FFT filtering theory are presented in this paper to solve the problem that the FFT can not precisely attain the expected filtering performance.The frequency response error of FFT is point out,and the error term is educed based on which the methods to completely avoid the error are presented.The reason caused the phase advance error is found and a effective method to solve this problem is presented.At last,a detailed discussion is presented about how to unchain the fixed relationship between the FFT length and the low-pass prototype filter length by using the frequency domain decimation and adding zeros,so that high quality of the prototype filter can be achieved and the filtering quality of FFT can be ulteriorly improved.更多还原