A frequency multiplex transmission device configured to transmit and receive a frequency multiplex signal having a plurality of subcarriers, the frequency multiplex transmission device comprising: a transmitter configured to transmit the frequency multiplex signal by using a plurality of modulation methods; a receiver configured to receive a signal state to the frequency multiplex signal from an opposite station; and a controller configured to obtain a signal state to each of the subcarriers on the basis of the received signal state and a frequency characteristic of an antenna included in the transmitter, the controller being configured to control transmission on the basis of an obtained result.