Near-perfect-reconstruction low-complexity two-band IIR/FIR QMF banks with FIR phase-compensation filters

In this paper, we present a novel approach for the design of near-perfect-reconstruction mixed allpass-/FIR-based two-band quadrature-mirror filter banks. The proposed design method is carried out in the polyphase domain, where FIR filters are employed for compensating the non-linear phase introduced by the allpass filters. In contrast to previous approaches in literature the FIR phase-compensation filters can be designed very efficiently using analytical expressions. Furthermore, starting from a generalized two-band structure, we introduce three special cases with different properties which are based on the same design principle. In all systems the remaining amplitude and phase distortions are controllable and can be made arbitrarily small at the expense of additional system delay. Simultaneously, aliasing can be minimized or completely canceled if further delay can be tolerated.