Summary: A BandwidthOptimized ReducedComplexity
Equalized Multicarrier Transceiver
Naofal AlDhahir \Lambda , Member, IEEE, and John M. Cioffi y , Fellow, IEEE
A bandwidth--optimized and equalized multicarrier transceiver that achieves near--optimum perfor
mance at a practical complexity level is described. The equalizer used is a relatively short FIR filter
whose taps and delay are set to optimize the performance of the multicarrier transceiver.
Simulation results on a set of carrier--serving--area digital subscriber loops are also presented to
demonstrate the separate and joint effects of bandwidth optimization and equalization on performance.
Finally, the intriguing idea of using a pole--zero equalizer to achieve the high performance of infinite--
complexity FIR equalizers at a much lower implementation cost is investigated.
The Discrete Multitone (DMT) transceiver has attracted considerable attention recently as
a viable technology for high--speed transmission on spectrally--shaped channels. Briefly, a DMT
modem uses an N--point Fast Fourier Transform (FFT) to partition the channel spectrum into
N ( N
) parallel, independent, and memoryless subchannels. To ensure the optimality of the
IFFT/FFT basis vectors as modulating/demodulating vectors (at least for the case of white noise),