Method and apparatus for cancelling in-band energy leakage from transmitter to receiver

A system for cancelling an undesired signal produced on a receiver line by a source of interference, comprising:

• means coupled to the source of interference for sampling a reference signal generated by the source of interference;
• means coupled to the receiver line for sampling a receiver signal comprised of the undesired signal and a desired signal;
• means for processing the reference signal and the receiver signal to generate a correction signal, the correction signal comprising estimates of the gain and phase of the undesired signal within the receiver signal;
• means for processing the reference signal and the correction signal to adjust the gain and phase of the reference signal according to the estimates of the gain and phase in the correction signal and generate a cancellation signal substantially gain and phase matched to the undesired signal;
• and
• means for subtracting the cancellation signal from the receiver signal to cancel the undesired signal produced on the receiver line.