Patent ID: 7860451

Claim:
An apparatus for controlling a power of a controlled relay, the apparatus comprising: a signal receiver which receives signals which are transmitted to a plurality of receiving antennas directly from a source or via at least one relay; a channel information acquisition unit which acquires channel information between the source and the at least one relay, and between the at least one relay and the plurality of receiving antennas; a power control signal generation unit which generates a power control signal, based on the acquired channel information and a signal-to-noise ratio (SNR) of at least one of the signals received; and a relay power control unit which transmits the generated power control signal to the controlled relay to control a transmit signal power of the controlled relay, wherein the SNR corresponds to a maximum SNR of the signals received which is calculated before the signals received are combined, and wherein the power control signal generation unit generates a power control signal based on an eigenvector corresponding to a maximum generalized eigenvalue with respect to each of the at least one relay, based on the acquired channel information and the maximum SNR.