A control part (101) outputs to a selection part (107) retransmission information as to whether a transmission signal is a retransmission signal or not and further, if yes, as to how-manieth retransmission signal it is. A spread part (102) spreads the transmission signal. An IFFT part (103) subjects the transmission signal to an orthogonal frequency division multiplex processing. A GI insertion part (104) inserts a guard section into the transmission signal. A GI insertion part (105) inserts, into the transmission signal, a guard section that is longer than the one inserted by the GI insertion part (104). A GI insertion part (106) inserts, into the transmission signal, a guard section that is longer than the ones inserted by the GI insertion parts (104,105). The selection part (107) selects, based on the retransmission information inputted from the control part (101), a transmission signal into which a longer guard section has been inserted as the number of retransmissions has become larger. This can prevent a transmission delay from becoming longer due to an excessively increased number of retransmissions with substantially no degradation of transmission efficiency. |