Patent ID: 8619744

Claim:
A reception method of a base station communicating with a plurality of mobile stations by radio communication using a frequency division multiplex system, comprising the steps of: converting reception signals all at once into signals of a frequency domain, said reception signals being sent from the plurality of mobile stations; recognizing, from the signals of the frequency domain, user signals corresponding to respective mobile stations by using sub-carriers selected in association with the respective mobile stations, wherein each user signal recognized is separated from other user signals; generating respective correction signals for correcting respective frequency offsets of respective user signals, wherein the generating said respective correction signals comprises; detecting the respective frequency offsets of the respective user signals using time domain channel response; averaging the respective frequency offsets with a predetermined time constant; calculating a complex sine wave based on the averaged respective frequency offsets; and generating said respective correction signals based on the complex sine wave; correcting the respective frequency offsets of the respective user signals in the frequency domain by the respective correction signals and demodulating the respective corrected user signals; wherein the generating said respective correction signals, the correction of the respective frequency offsets and the demodulation are executed for said each user signal from which the other user signals are already separated.