An Efficient Constrained Optimisation Method for Designing Two-Channel Quadrature Mirror Filter Banks

In this paper, a constrained optimisation technique is used to design quadrature mirror filter banks with linear phase in frequency domain. A unique method is developed in which the design problem is formulated as a constrained optimisation that minimises the weighted sum of error of transfer function of the filter bank at quadrature frequency, stopband energy, the passband error and measure of ripple of the prototype filter. Numerical examples and comparisons with several existing methods are included to show the performances and the effectiveness of the proposed method in terms of reconstruction error, mean square error in passband and mean square error in stopbands.