A Computationally Efficient Technique to Design Two-Channel Quadrature Mirror Filter Banks

An efficient technique for designing two-channel finite impulse response quadrature mirror filter (QMF) bank is proposed. Low-pass analysis prototype filter of the filter bank is represented in polyphase form to reduce the computational complexity. An optimization problem is formulated as linear combination of square error of the overall transfer function of the QMF bank at the quadrature frequency and pass-band error, and stop-band residual energy of the low-pass analysis filter. An iterative solution which involves the computation of eigenvector corresponding to minimum eigenvalue of a matrix with a dimensionality equal to one half of filter coefficients is suggested. Simulation results show that the proposed method reduces the computational time and number of iterations with almost same peak reconstruction error (PRE) performance in comparison to other existing techniques. Design examples are included, illustrating the effectiveness and superiority of the proposed approach.