Method for estimating self-interference signal based on iterative estimation and apparatus using the same

An apparatus for estimating a self-interference signal, comprising:

• a processor configured to
• estimate third-order nonlinear distortion, which distorts a self-interference signal, based on a transmission signal and a reception signal for two preamble signals that are transmitted from a transmission antenna of a terminal to a reception antenna of the terminal,
• update the reception signal by eliminating the third-order nonlinear distortion from the reception signal,
• re-estimate the third-order nonlinear distortion based on the updated reception signal, and
• estimate the self-interference signal based on a final third-order nonlinear distortion, which is acquired by iteratively re-estimating the third-order nonlinear distortion;
• and
• a memory configured to store the transmission signal, the reception signal, and either one or both of the third-order nonlinear distortion and the final third-order nonlinear distortion,
• wherein the processor is further configured to estimate a channel coefficient for a channel between the transmission antenna and the reception antenna, estimate nonlinear distortion gain, generated by a High-Power Amplifier (HPA) for amplifying the transmission signal, based on the channel coefficient, and estimate a nonlinear factor, an order of which corresponds to a third-order Intercept Point (IP3), in a signal that is input to the HPA based on the channel coefficient and the nonlinear distortion gain.