Design of stable IIR digital filters with equiripple passbands and peak-constrained least-squares stopbands

This paper describes an algorithmic development for the design of stable infinite impulse response (IIR) digital filters with equiripple passbands and peak-constrained least-squares stopbands. Central to the development is a re-formulation of the design problem as an iterative quadratic programming problem where the stability and equiripple passbands and peak-constrained requirements are met by imposing a system of linear inequality constraints while the LSS property is satisfied by minimizing a weighted least-squares type objective function.