The invention reveals a multicarrier communication, especially relating to residual frequency offset (RFO) compensating method and system for OFDM communication system. And the method comprises: in the first operating stage, each time only processing phase variation value of the current OFDM data symbol and then obtaining residual frequency estimated value to feed back to compensate demodulated variable carrier; and in the second operating stage, each time making operation of multiple OFDM data symbols to obtain corresponding residual frequency estimated values and then compensating the demodulated variable carrier. And the system comprises: discrete Fourier transform (DFT) unit, packing the received OFDM signal for DFT operation; phase variation detector, connected with the DFT unit to detect phase variation values of multiple OFDM data symbols; and residual frequency estimator, connected with the phase variation detector and obtaining the residual frequency estimated values according to the above phase variation values of multiple data symbols and the above compensating method. |