Patent ID: 6236645
Filing Date: 2001-05-22
Classification: H04B

Abstract:
A communications system comprising:a communication line having a plurality of twisted wire pairs;a plurality of transmitters, one transmitter at each end of each twisted wire pair;a plurality of receivers, one receiver at each end of each twisted wire pair, each receiver receiving a combination signal including a direct signal from the transmitter at the opposite end of the twisted wire pair with which the receiver is associated and a plurality of far-end crosstalk (FEXT) impairment signals, one from each of the remaining transmitters at the opposite end of the communications line;a plurality of FEXT cancellation systems, one associated with each receiver, each FEXT cancellation system for providing a replica FEXT impairment signal; anda plurality of devices, one associated with each receiver, each device responsive to the combination signal received by such receiver and the replica FEXT impairment signal provided by the FEXT cancellation system associated with such receiver for substantially removing the FEXT impairment signals from the combination signal;wherein each FEXT cancellation system is responsive to a tentative decision signal from a tentative decision detector in a digital adaptive filter system in each receiver, the each tentative decision detector being coupled to receive and derive the tentative decision signal from the combination signal before replica FEXT impairment signals are applied to each of the plurality of devices to remove the FEXT impairment signals from the combination signal.