Weighted least-squares design of recursive allpass filters
Sunder S. Kidambi · IEEE Transactions on Signal Processing · 1996
A method for the design of allpass filters is described. In this method, an error reflecting the difference between the desired phase response and the phase response of the practical allpass filter is formulated in a quadratic form. The coefficients are obtained by solving a system of linear equations involving the sum of a Toeplitz and an Hankel matrix.