Wideband crosstalk interference cancelling on xDSL using adaptive signal processing and common mode signal

Crosstalk originating from multiple high-speed data services in the same telephone bundle is a limiting factor for the maximum bit rate, the loop length and the number of data services that a bundle can support. Due to the nature of twisted-pairs, external interferences (including crosstalk) mostly couple to the twisted-pair line in common mode, and then leaks to differential mode due to line imperfect balance. The result is a degradation of the received differential signal quality. This paper uses the common mode signal as a reference to an adaptive wideband crosstalk canceller, as an attempt to remove the effect of crosstalk on the differential signal. Simulation results show the potential benefits of using this technique to reduce the crosstalk levels.