an oscillation signal generator configured to generate a plurality of oscillation signals having a delay interval with each other and having the same phase and amplitude or different phases and amplitudes;

an envelope signal generator configured to extract a sync signal and a data signal making up communication signal data and generate an envelope signal for the sync signal and an envelope signal for the data signal;

a signal synthesizer configured to synthesize the plurality of oscillation signals with the envelope signals to generate an impulse signal;

an envelope signal extractor synchronized with the oscillation signal generator based on the sync signal and configured to extract a plurality of modulation envelope signals from the impulse signal;

an amplitude phase determiner configured to determine the phase and the amplitude in the plurality of modulation envelope signals based on the plurality of oscillation signals; and

a calculator configured to extract the envelope signals from the plurality of modulation envelope signals based on the phase and the amplitude.