A method and apparatus for outbound wave subtraction using a variable
offset amplifier is described. The method includes calibration of a
bi-directional signaling circuit in order to calculate one or more offset
codes for cancellation of an outbound wave within a bi-directional
communications link. Once the one or more offset codes are calculated, it
is determined whether a dual inbound wave is received by the
bi-directional signaling circuit. Once received, an offset code from the
one or more calculated offset codes is selected according to a value of
an outbound wave within the dual inbound/outbound wave. Finally, the
outbound wave is cancelled from the dual inbound wave at an output of a
variable offset amplifier using the selected offset code.