An interference cancellation repeater according to the inventive concept includes: a first transmission/reception processing unit configured to adjust a gain of a radio frequency (RF) input signal input via a link antenna communicatively coupled to a base station; an interference canceller configured to cancel and output an interference signal from an output signal of the first transmission/reception processing unit; and a gain controller configured to extract a signal with constant magnitude regardless of a change in user traffic from the output signal of the interference canceller, and to adjust the gain of the RF input signal to a predetermined level by controlling the first transmission/reception processing unit based on the extracted signal.

Certain features relate to operating a distributed antenna system or repeater system communicating frequency-division duplexing (FDD) signals in a time-division duplexing (TDD) mode. A TDD mode scheduler is configured for monitoring a downlink communications channel for the start of a downlink frame, sub-frame, or resource slot. Based on the start of a downlink frame, sub-frame, or resource slot, the TDD mode scheduler can identify a TDD transmission time-slot. The TDD mode scheduler can schedule high-powered downlink sub-frames during the TDD transmission time-slots where higher power output may be desirable. Based on the indication of the TDD transmission time-slot, a transmit/receive controller can increase the gain of the downlink communication and reduce the gain of the uplink communication.

Provided is an interference cancellation relay device. The interference cancellation relay device includes: an interference cancellation unit cancelling an interference signal from an input signal and outputting the input signal from which the interference signal is removed; a gain control unit controlling a gain of an output signal of the interference cancellation unit; and a pre-distortion unit distorting the output signal of the interference cancellation unit, of which the gain is controlled by the gain control unit.

An apparatus, and method relating to control of radio repeaters is disclosed. The apparatus may comprise a means for transmitting one or more reference signals at a transmit power level using a transmit antenna of a repeater. The apparatus may also comprise a means for measuring a receive power level of the corresponding one or more reference signals received using a receive antenna of the repeater and determining a self interference power value based on the difference between the transmit power level of the one or more reference signals and the receive power level of the one or more corresponding reference signals. The apparatus may modify a gain associated with an amplifying means of the repeater based on the determined self-interference value.