Patent ID: 8725067

Claim:
A self-interference cancellation apparatus comprising: a channel estimator estimating a radio channel between a transmit antenna of a relay and a receive antenna of the relay; an estimated self-interference generator generating an estimated self-interference based on an estimated radio channel; and a self-interference cancellation unit canceling the estimated self-interference in a received signal received via the receive antenna, wherein the relay transmits data and comprises: a reference signal generator configured to generate self-interference cancellation reference signal and an uplink reference signal, generating the uplink reference signal using an uplink reference signal sequence that is selected from a reference signal sequence group including a plurality of reference signal sequences, for the base station to perform a coherent demodulation, and a transmitter to transmit the self-interference cancellation reference signal, the data, and the uplink reference signal to a base station accessing the relay, and wherein the channel estimator receives the self-interference cancellation reference signal and estimates a radio channel based on the received self-interference cancellation reference signal.