An improved method for the design of FIR quadrature mirror-image filter banks

A new method for the design of general finite-duration impulse response (FIR) quadrature mirror-image filter (QMF) banks that eliminates the computation of large matrices is proposed. The design problem is formulated to include low-delay QMF banks, which are highly desirable in some applications. The paper concludes with design results and comparisons that show that conventional QMF banks can be designed with only a fraction of the computational effort required by a method due to Chen and Lee (1992). On the other hand, in the case of low-delay QMF banks, the proposed method can increase the stopband attenuation substantially compared with what can be achieved by existing methods