A radio communication system divides an entire frequency band into a plurality of subcarrier bands, forms a symbol with signals on the subcarrier bands, forms a frame with a plurality of symbols, transmits a pilot signal within symbols in a predetermined position of the frame, and transmits a data signal within symbols other than the symbols for transmitting the pilot signal. A transmitter allocates subcarriers through which the reference signal is transmitted, wherein the subcarriers are allocated to have an exclusive relation with subcarriers through which reference signals of other transmitters are transmitted, generates the pilot signal, performs an inverse fast Fourier transform (IFFT) on the pilot signal by applying an IFFT size which is less than or equal to an IFFT size applied to the data signal, and transmits the IFFT-processed reference signal to a receiver.