A method of decoding a backhaul downlink signal of a relay node (RN), the method includes receiving a higher layer signal indicating a maximum transmission rank from a base station (BS), receiving control information through a relay control channel from the BS, and demodulating the control information, wherein the control information is mapped to resource elements which do not overlap with user equipment-specific reference signal resource elements (URS REs) in a control region which is used for the relay control channel transmission of the BS, the URS REs being reserved resource elements for user equipment-specific reference signals (URSs) according to the maximum transmission rank, and wherein the control information is demodulated based on user equipment-specific reference signals transmitted by the BS on one fixed antenna port n, where n is a natural number.