以低階線性相位無限脈衝響應濾波器快速近似有限脈衝響應濾波器之數位濾波器設計工具Apparatus and method for efficiently approximating FIR filters by low-order linear-phase IIR filters

A method and apparatus, called the intelligent multipoint Arnoldi (IMA) method, for approximating FIR filters by low-order linear-phase IIR filters is disclosed. Based on special realizations of FIR filters, iterative natures of the Arnoldi algorithm, and frequency expansion points selection scheme, the proposed method is very efficient to determine the low-order IIR filters in terms of computational complexity. The low-order IIR filter can truly reflect dynamical features of the FIR filter and indeed satisfies original design specifications.