On the capacity of the copper cable channel using the common mode

The common-mode (CM) signal in wireline transmission systems has proven to provide valuable information exploited for mitigating narrowband noise at the receive side. We focus on the case of broadband noise. Treating the CM signal as an additional receive signal, we investigate the capacity of the copper cable channel for different levels of coordination among the users. We introduce a channel model which includes the common-mode paths and derive a suitable form of the channel capacity formula. CM crosstalk measurement results, essential for evaluation of the channel capacity, are presented. Using the measurement data, exemplary results of capacity gain achievable by CM-aided data transmission over the copper cable are shown.