An improved and simplified design of cosine-modulated pseudo-QMF filterbanks

In this paper, a simple and efficient design of prototype filters for cosine-modulated filterbanks is proposed. Variable combinational window function with high side-lobe-fall-off-rate (SLFOR) has been used to design the prototype filter for cosine-modulated filterbanks. Cutoff frequency of the filter is optimized to minimize the reconstruction error, which is also selected as an objective function. Very small values of reconstruction and aliasing errors have been obtained with high SLFOR combinational window filters, resulting in near perfect reconstruction (NPR) filterbanks. However, higher filter order is required to get NPR solution.