Patent ID: 8218520

Claim:
A method of transmitting an uplink ACKnowledge CHannel (ACKCH) for a downlink data channel in a mobile communication system using Orthogonal Frequency-Division Multiple Access (OFDMA), the method comprising: receiving a downlink control channel; receiving a downlink data channel; generating uplink acknowledgement information by analyzing the received downlink data channel; assigning, if the downlink control channel includes at least two Control Channel Elements (CCEs), at least two channel resources for the uplink acknowledgement information using Orthogonal Cover (OC) and Cyclic Shift (CS); and transmitting the uplink ACKCH including the uplink acknowledgement information on the channel resources through at least two transmission antennas, wherein the channel resources comprise a first channel resource and a second channel resource, the first channel resource for a first transmission antenna is assigned based on a lowest CCE index n CCE among the at least two CCEs, and the second channel resource for a second transmission antenna is assigned based on a CCE index n CCE +1.