Patent ID: 8315639

Claim:
A wireless communication system configured to participate in cooperative communication, the wireless communication system comprising: a relay station configured to transmit an orthogonal frequency division multiplexing (OFDM) symbol to a first user equipment (UE) with a first transmission pattern of reference signals selected from available transmission patterns via a first frequency band during a transmission duration, receive uplink data from the first UE via a second frequency band different from the first frequency band during the transmission duration, and not transmit allocation information related to the first transmission pattern; and a base station configured to transmit the OFDM symbol to the relay station with a second transmission pattern of reference signals selected from the available transmission patterns via the second frequency band during the transmission duration, and not transmit allocation information related to the second transmission pattern, wherein the available transmission patterns include a first pattern in which odd subframes include reference signals and even subframes do not include reference signals, a second pattern in which even subframes include reference signals and odd subframes do not include reference signals, and a third pattern in which every subframe includes reference signals, wherein the first transmission pattern is different from the second transmission pattern, wherein the OFDM symbol includes a frame consisting of ten subframes, and wherein the first UE is configured to detect the first transmission pattern by correlating the available transmission patterns with a received signal without using the allocation information.