Efficient design considerations of QMF banks with low delay

Investigation have been carried out on the iterative method proposed by Wu-Sheng (see IEEE Trans on Signal Proc., vo1.46, p.1275-81, 1998) to design an efficient QMF banks with approximately constant group delay. Simulations show that it is quite sensitive to the choice of the initial filter. A new and important benefit of manipulating the initial filter design of QMF banks is its ability to design QMF banks with low and approximately constant group delay. By using a linear minimum phase efficient method proposed by Ivan (1996) as the initial filter, improvements in most of the design specifications Wu-Sheng have been obtained. The constraint of the transition band is added in the initial condition. Computer simulation shows that the proposed approach produce better results than those reported previously. However, the proposed approach requires more computational efficiency compared with existing methods.