OFDMA system and method for controlling frequency offsets of subscribers in uplink communication

Provided are an orthogonal frequency division multiple assess (OFDMA) system and a method for controlling frequency offsets of subscribers in uplink communication. The OFDMA system solves a problem that the system performance is deteriorated in uplink communications because subscriber stations have different carrier frequency offsets. Each subscriber station compensates for a frequency offset thereof in response to a frequency offset control signal provided by a base station and then transmits an uplink frame to the base station. The base station compensates for an average frequency offset using the uplink frame, which has a small frequency offset shift because each subscriber station compensates for the frequency offset thereof previously, and thus the frequency offset of each subscriber station can be correctly compensated to prevent inter-carrier interference.