Rejection of transmit signal leakage in wireless communication device

A method for filtering a transmit (TX) leakage signal from a received input signal in a radio frequency (RF) receiver, the method comprising:

• receiving an RF receive (RX) input signal having a TX leakage signal;
• subtracting a TX leakage signal estimate from the input signal to produce an output signal;
• and
• generating the TX leakage signal estimate exclusive of a TX signal and based on the output signal and an unmodulated reference signal at a carrier frequency of the TX leakage signal.

A filter circuit for a radio frequency (RF) receiver, the filter circuit comprising:

• means for receiving an RF receive (RX) input signal having a transmit (TX) leakage signal;
• means for subtracting a TX leakage signal estimate from the input signal to produce an output signal;
• and
• means for generating the TX leakage signal estimate exclusive of a TX signal and based on the output signal and an unmodulated reference signal at a carrier frequency of the TX leakage signal.

A radio frequency (RF) receiver, the receiver comprising:

• an antenna that receives a receive (RX) input signal;
• an amplifier that amplifies the RX input signal;
• a duplexer that couples the RX input signal from the antenna to the amplifier, and passes a transmit (TX) leakage signal to the amplifier as part of the RX input signal;
• a summer that subtracts a TX leakage signal estimate from the RX input signal to produce an RX output signal;
• an estimator that generates the TX leakage signal estimate exclusive of a TX signal and based on the RX output signal and an unmodulated reference signal at a carrier frequency of the TX leakage signal;
• and
• a mixer that downconverts the RX output signal to a baseband.