Adaptive equalization for partially bandwidth-occupied ADSL transceivers

A new optimization criterion for the design of a time-domain equalizer in asymmetric digital subscriber line systems is studied. It is shown that the new criterion maximizes the signal-to-noise ratio regardless of the profile of bandwidth occupancy. Based on the fact that the solution of the optimization problem is unique, two adaptation algorithms are developed in the time and frequency domains, respectively. The computational complexities of these two algorithms are comparable to that of the conventional least-mean-square algorithm. Simulation results show that the two algorithms converge at a satisfactory speed but the frequency-domain algorithm offers a slightly faster convergence and a smaller excess mean-square error.