Abstract: A method for uplink transmission in an OFDMA system is provided. The subcarrier transmission method includes arranging 4 pilot REs at different positions of a frequency axis in a basic unit when the basic unit includes 4 subcarriers on the frequency axis and 6 OFDM(A) symbols in a time axis, arranging data REs at remaining positions of the basic unit, and transmitting the basic unit to a receiving end.

Abstract: Provided are an apparatus and a method for monitoring a control channel in a multiple-carrier system. The user equipment monitors downlink control channels for a plurality of scheduled component carriers in an extended search space. The user equipment receives downlink control information for the scheduled component carrier via a successfully decoded downlink control channel.

Abstract: A method and apparatus of relaying data in a wireless communication system is provided. A relay station (RS) receives relay zone allocation information. A plurality of relay zones is allocated in a resource region by the relay zone allocation information. The relay station receives data transmitted from a super-ordinate station, detects a tunneling traffic destined to a subordinate station from the data, and transmits the tunneling traffic to the subordinate station. The tunneling traffic is transmitted over one of the plurality of relay zones.

Abstract: A method for uplink transmission in an OFDMA system is provided. The subcarrier transmission method includes arranging 4 pilot REs at different positions of a frequency axis in a basic unit when the basic unit includes 4 subcarriers on the frequency axis and 6 OFDM(A) symbols in a time axis, arranging data REs at remaining positions of the basic unit, and transmitting the basic unit to a receiving end.

Abstract: A device and method for communicating by a mobile communication terminal in communication with a base station. The method according to an embodiment includes exchanging a frame of data with the base station. The frame of data includes a) a plurality of first subframes each having a first number of orthogonal frequency division multiple access (OFDMA) symbols, and b) a plurality of second subframes each having a second number of orthogonal frequency division multiple access (OFDMA) symbols different from the first number. One of the second subframes includes an idle symbol.