Interference cancellation circuit and operating method thereof

An operating method performed by an interference cancellation circuit, the operating method comprising:

• receiving a transmission path signal and a reception path signal;
• generating an activation control signal based on the transmission path signal and the reception path signal;
• setting a forgetting factor to a smallest first value from among a set of a first value to an N-th value based on the activation control signal;
• and
• comparing a control metric with a plurality of threshold values and setting the forgetting factor up to the N-th value based on the control metric compared with the plurality of threshold values.

A wireless communication device comprising:

• a first transmission radio frequency (RF) chain configured to output a first transmission signal;
• a second transmission RF chain configured to output a second transmission signal;
• a reception RF chain corresponding to a reception path in which a reception signal is input;
• and
• an interference cancellation circuit comprising:
• an activation circuit configured to generate an activation control signal in response to receiving (i) a first transmission path signal corresponding to the first transmission RF chain, (ii) a second transmission path signal corresponding to the second transmission RF chain, and (iii) a reception path signal corresponding to the reception RF chain,
• a forgetting factor control circuit configured to compare a control metric with a plurality of threshold values and configured to control a forgetting factor value based on the compared control metric with the plurality of threshold values,
• a kernel generation circuit configured to receive the first transmission signal and the second transmission signal and configured to generate an interference model, and
• an adaptive filter configured to receive a kernel signal from the kernel generation circuit, and configured to receive the forgetting factor value from the forgetting factor control circuit to cancel self-interference.