A communication circuit comprises a near end transmitter, and adjustable
near end replication transmitter and a near end receiver. The near end
transmitter is configured to generate a transmission signal and comprises
a first plurality of current sources. Outputs of the first plurality of
current sources are summed to generate the transmission signal. The
adjustable near end replication transmitter comprises a second plurality
of current sources. Outputs of the second plurality of current sources
are summed to generate a replication signal in accordance with the
transmission signal. The replication signal from the adjustable near end
replication transmitter is subtracted from the transmission signal from
the near end transmitter and a received signal from a communication
channel to generate a subtraction signal. The near end receiver is
configured to receive the subtraction signal.