On WLS-Chebyshev IIR digital filters
Sergio Lima Netto, Paulo S. R. Diniz · 2003
A method for approximating infinite-duration impulse response (IIR) digital filters is given. The method is able to compromise maximum stopband attenuation and minimum stopband energy requirements. The proposed approach performs a series of weighted-least-squares (WLS) iterations, with a weight function which is made constant within a given frequency interval at each iteration. The highly nonlinear problem characteristic of IIR filter design is pseudo-linearized using the Steiglitz-McBride formulation. As a result, IIR digital filters with partially WLS-like and partially equiripple stopbands are efficiently designed.