Patent ID: 7586834

Claim:
A method for transmitting uplink acknowledge (ACK) information in a communication system using an orthogonal frequency division multiple access (OFDMA) scheme, the method comprising: generating uplink ACK information to be transmitted in consideration of downlink packet status; channel-encoding the uplink ACK information into a codeword; determining modulation symbols corresponding to the codeword by performing orthogonal modulation; and transmitting the modulation symbols allocated to predetermined subcarrier clusters, wherein the modulation symbols are defined by an ACK vector index from: ACK vector index ACK bit Tile 0 Tile 1 Tile 2 0 0 0 0 1 4 7 2 where the ACK bit indicates the uplink ACK information, each of the ACK vector indexes indicates a predetermined set of modulation symbols, and each of the tiles includes a predetermined number of subcarriers.