Envelope-constrained IIR filter design via Laguerre functions and ℋ∞ optimization methods

Envelope-constrained filtering problem is concerned with the design of a time-invariant filter to process a given input signal such that the output of the filter is guaranteed to be within a prespecified output mask. Using discrete-time Laguerre functions and ℋ_∞ optimization techniques, the envelope-constrained IIR filter design problem has been reformulated and solved as an ℋ_∞ model matching problem. To illustrate the usefulness of the design method, a numerical example is presented which is concerned with the design of an equalization filter for a digital transmission channel