ISI-free FIR filterbank transceivers for frequency-selective channels

Discrete multitone modulation transceivers (DMTs) have been shown to be very useful for data transmission over frequency-selective channels. The DMT scheme is realized by a transceiver that divides the channel into subbands. The efficiency of the scheme depends on the frequency selectivity of the transmitting and receiving filters. The receiving filters with good stopband attenuation are also desired for combating narrowband noise. The filterbank transceiver or discrete wavelet multitone (DWMT) system has been proposed as an implementation of the DMT transceiver that has better frequency band separation, but usually, intersymbol interference (ISI) cannot be completely cancelled in these filterbank transceivers, and additional equalization is required. We show how to use over interpolated filterbanks to design ISI-free FIR transceivers. A finite impulse response (FIR) transceiver with good frequency selectivity can be designed, as demonstrated by the design examples.