Receiving device, receiving method, and receiving system

A receiving system comprising:

• a reception signal input circuit configured to input a reception signal of a radio wave;
• a demodulation processor configured to perform demodulation processing of the reception signal;
• and
• a sound signal output circuit configured to sound-output a demodulation signal,
• wherein the reception signal input circuit comprises an antenna configured to receive a radio wave of a desired wave and an input signal amplifier configured to amplify a received signal,
• wherein the sound signal output circuit comprises an output signal amplifier configured to amplify the demodulation signal, and a sound output device configured to output an amplified signal as a sound signal, and
• wherein the demodulation processor comprises:
• a frequency mixer configured to mix the reception signal input from the reception signal input circuit and a local signal generated by a local oscillator to convert a frequency of the reception signal to a baseband;
• an envelope demodulator configured to perform envelope demodulation of an output from the frequency mixer;
• an upper sideband demodulator configured to demodulate only an upper sideband of the output from the frequency mixer by single sideband demodulation;
• a lower sideband demodulator configured to demodulate only a lower sideband of the output from the frequency mixer by the single sideband demodulation;
• a first adder configured to add an output from the envelope demodulator and a first inverted output obtained by inverting an output from the upper sideband demodulator;
• a second adder configured to add the output from the envelope demodulator and a second inverted output obtained by inverting an output from the lower sideband demodulator;
• and
• a third adder configured to add the output from the envelope demodulator, a third inverted output obtained by inverting an output from the first adder, and a fourth inverted output obtained by inverting an output from the second adder, to output the demodulation signal.

A receiving method comprising:

• causing a frequency mixer to mix a reception signal input thereto and a local signal generated by a local oscillator to convert a frequency of the reception signal to a baseband;
• causing an envelope demodulator to perform envelope demodulation of an output from the frequency mixer;
• causing an upper sideband demodulator to demodulate only an upper sideband of the output from the frequency mixer by single sideband demodulation;
• causing a lower sideband demodulator to demodulate only a lower sideband of the output from the frequency mixer by the single sideband demodulation;
• causing a first adder to add an output from the envelope demodulator and a first inverted output obtained by inverting an output from the upper sideband demodulator;
• causing a second adder to add the output from the envelope demodulator and a second inverted output obtained by inverting an output from the lower sideband demodulator;
• and
• causing a third adder to add the output from the envelope demodulator, a third inverted output obtained by inverting an output from the first adder, and a fourth inverted output obtained by inverting an output from the second adder, to output a demodulation signal.