基于扩展傅里叶变换的可变带宽滤波器设计  

Design of variable-bandwidth filter based on EFT

作　　者：吴伟[1] 唐斌[1] 

机构地区：[1]电子科技大学电子工程学院,成都610054

出　　处：《仪器仪表学报》2007年第5期826-831,共6页Chinese Journal of Scientific Instrument

基　　金：国防预研项目(41101041101030402)资助

摘　　要：本文提出了一种基于扩展傅里叶变换(EFT)的可变带宽滤波器(VBF)设计方法。文中定义了扩展傅里叶变换和线性准时不变(LQTI)系统,分析了线性准时不变系统在扩展傅里叶变换域的频率特性,并利用线性准时不变系统的可变带宽频率特性来构建可变带宽滤波器,同时详细分析了可变带宽滤波器的通带变化情况。这种可变带宽滤波器基于一种简单的更新机制,能够有效降低运行时的复杂度。实验结果证明了基于扩展傅里叶变换的可变带宽滤波器的有效性。This paper proposes a design technique of variable-bandwidth filter （VBF） based on extended Fourier transform （ EFT）. The frequency characteristics of the variable-bandwidth filter are derived by investigating the linear quasi-time-invariant （LQTI） system and analyzing its extended Fourier transform frequency characteristics. The frequency characteristics of four kinds of variable-bandwidth filters are discussed. Based on a simple updating mechanism, the proposed variable-bandwidth filter can considerably reduce the complexity during normal operations. Design examples are provided, and experiment results illustrate the correctness and validity of the variable-bandwidth filter based on extended Fourier transform.

关 键 词：可变带宽滤波器 线性准时不变系统 扩展傅里叶变换 时变信号处理 

分 类 号：TN957[电子电信—信号与信息处理]