To provide a device where a high speed modulation signal on a low speed modulation signal transmitted by superimposing it with the high speed modulation signal is removed and the quality of the low speed modulation signal that is not superimposed is not deteriorated by applying the removal of the high speed modulation signal only to the demodulation means of the low speed modulation signal superimposed with the high speed modulation signal.

A demodulation means corresponding to a low speed modulation signal which is not superimposed with a high speed modulation signal demodulates a reception signal and the demodulation means corresponding to the low speed modulation signal superimposed with the high speed modulation signal demodulates the output signal of a synthesis means. In the device, a variable delay unit 701, a variable phase shifter 704 and a variable attenuator 705 adjust the delay time, the phase and the amplitude so that the amplitude of the high speed modulation signal S5 and that of a replica signal r1, which are contained in a repeater output signal, become equal and the phases become opposite. Thus, the high speed modulation signal S5 is removed from the output signal of a synthesizer 706. The low speed modulation signals S1 and S2 are taken out from the output signal of the synthesizer 706 by channel filters 711 and 721.