ORTHOGONAL FREQUENCY-DIVISION MULTIPLEX TRANSMISSION METHOD

摘要

A spread modulator 1 spreads a signal series. A subcarrier modulator 2 modulates a plurality of subcarriers having different frequencies using the output of the spread modulator 1. The adder 3 combines modulated subcarriers. A guard interval control unit 23 determines the length of a guard interval depending on the maximum transmission delay difference of the communication link between the transmission device and the reception device. A guard interval insert unit 21 inserts a guard interval into a signal series under the control of a guard interval control unit 23. A gain adjuster 22 multiplies a transmission signal by a gain coefficient corresponding to the inserted guard interval. <IMAGE>