A new algorithm for designing prototype filters for M-band Pseudo QMF banks

This paper presents a simple and efficient method to design M-band Pseudo Quadrature Mirror Filter (QMF) banks. This method does not rely on a conventional nonlinear optimization method but rather on an Iterative Least Squares algorithm. The algorithm is rapidly converging, simple to implement and flexible. Its convergence does not depend on the starting point. Moreover iteratively calculated weighting functions can be used to shape the stopband of the prototype filter and the filter bank transfer function, and perform the minimax or the gain constrained least squares approximation. Design examples and a MATLAB program implementing the proposed algorithm are included.