A retransmission control apparatus for use in a radio communication system that uses an orthogonal frequency division multiplexing technique, the apparatus comprising a transmitter which transmits to a radio station a data sequence, which serves as communication data that has been transformed into a time waveform of an orthogonal frequency division multiplexing symbol; a receiver which receives from the radio station a retransmission request for retransmitting the communication data; a transformation mechanism configured to transform, in response to the retransmission request, the data sequence of the communication data to be retransmitted into an orthogonal frequency division multiplexing symbol having a time waveform different from the time waveform of the orthogonal division multiplexing symbol which had been sent before the retransmission request; and a retransmitting mechanism configured to retransmit the communication data transformed by the transformation mechanism to the radio station. Since the time waveform of the resulting OFDM data symbol after the retransmitting operation is changed from that before the retransmitting operation, it is highly likely that the average power of the transmitting signal is increased. As a result, the occurrence of errors when the data sequence is retransmitted is reduced, thereby improving the throughput.