Information rate bounds in common-mode aided wireline communications

Communication over the copper twisted-pair channel is performed by transmitting and receiving differential-mode (DM) signals. In this paper, we extend the conventional DM receiver scheme by incorporating the common-mode (CM) signal, which is strongly correlated with the DM signal and can be extracted at the end of every wire pair. The wireline channel, including the CM receive signal, is modelled as a Gaussian vector (multiple-input multiple-output) channel with memory and an arbitrary number of disturbers that introduce interference which can be correlated both temporally and spatially. We investigate the potential of CM-aided reception in terms of information rate for single-user digital subscriber line systems (xDSL) operating on a single pair. Numerical results of information rate calculations using measured channel data are presented. The achievable information rate of the twisted-pair channel when incorporating the CM signal in practically relevant example scenarios can exceed the information rate of the conventional DM channel by a factor of up to two. Copyright (C) 2005 AEIT.