Nearly perfect-reconstruction cosine-modulated filter bank design for VDSL modems

In our previous paper, we applied the idea of perfect-reconstruction cosine-modulated filter banks to develop efficient transmultiplexers for multicarrier VDSL transmission systems of the discrete wavelet multitone type. However, it is sometimes judicious to relax perfect-reconstruction conditions by allowing amplitude and/or aliasing distortions. In this paper, we present a nearly perfect-reconstruction cosine-modulated transmultiplexer approach for VDSL modems. The effects of design parameters (roll-off, filter length, maximum allowable amplitude distortion, and maximum allowable aliasing distortion) on the performance of the transmultiplexer systems are evaluated through design examples.