一种改进的开关电流滤波器实现小波变换的方法  

An improved method for implementation of wavelet transform utilizing switched-current filters

作　　者：赵文山[1] 何怡刚[1] 

机构地区：[1]湖南大学电气与信息工程学院,长沙410082

出　　处：《物理学报》2009年第2期843-851,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50677014;60876022);高等学校博士点专项科研基金(批准号:20060532002);国家高技术研究发展计划(批准号:2006AA04A104);湖南省科技计划项目(批准号:06JJ2024;03GKY3115;04FJ2003;05GK2005);教育部新世纪优秀人才支持计划(批准号:NCET-04-0767)资助的课题~~

摘　　要：提出了一种小波变换的开关电流滤波器实现的新方案,基于网络函数逼近理论,采用一种函数逼近的系统算法将基本小波函数综合为有理分式和,并利用开关电流并联结构实现该基本小波函数滤波器.以高斯一阶导数函数为例,给出了逼近网络的具体构造过程和开关电流滤波器实现结构.该滤波器网络由六个以S2I存储单元为核的双二次开关电流滤波器并联而成.理论分析和仿真结果表明,新方案比原有实现方法在逼近精度、系统稳定性、电路性能方面均有明显改善.A new scheme of implementing wavelet transform using switched-current filters is proposed in this paper. Based on approximation theory of network function, the basic wavelet function is synthesized with the sum of rational fraction obtained by a systematic algorithm. And then the basic wavelet function filter is implemented by a parallel structure of switched-current circuits. Herein, the first derivative of Gaussian function is selected as an example with the construction procedure of approximation network and structure of switched-current filters elaborated. The filter network employs six biquadratic switched-current filters in a parallel connection, in which the S^2I memory cell is used as the core of the filter. Theoretical analysis and simulation result show that the proposed scheme is superior to the original method in approximation precision, system stability and circuit performance.

关 键 词：小波变换 开关电流 网络函数逼近 有理分式综合 

分 类 号：TN713[电子电信—电路与系统]