An optical wavelength multiplexing frequency shift keying modulation
system. The system includes an optical wavelength multiplexing signal
acquisition unit for outputting an optical wavelength multiplexing
signal. A n optical frequency shift keying modulation unit acquires an
optical frequency shift keying signal, including an upper side band
signal and a lower side band signal, by performing frequency modulation
to the optical wavelength multiplexing signal output from the optical
wavelength multiplexing signal acquisition unit. An optical frequency
shift keying signal separation unit separates the optical frequency shift
keying signal output from the optical frequency shift keying modulation
unit into an upper side band signal and a lower side band signal.