| 摘要 |
PURPOSE:To easily add information transmission without enlarging any transmission band and without altering any modulation/demodulation circuit for main information concerning the transmitter for multiplexing sub information to FM modulated main information and transmitting it. CONSTITUTION:A transmitter 1 on the transmission side converts the analog signal of added sub information to a PCM code while using a PCM coding part 3, performs AM modulation to the FM modulated signal of main information corresponding to this PCM code signal while using an AM modulating part 4, generates a signal provided with two amplitude values and transmits it to a transmission line. A transmitter 6 on the reception side inputs the signal received from the transmission line to an AM demodulating part 8, generates a PCM code signal, outputs an FM signal, inputs the PCM code signal to a PCM decoding part 9, decodes analog sub information, inputs the outputted FM signal to an FM demodulating part 10 and outputs the main information. |
