| 摘要 |
PROBLEM TO BE SOLVED: To substantially improve frequency utilization efficiency and power utilization efficiency in a digital communication system and a radio device.SOLUTION: A digital communication system converts digital information data to be transmitted into multi-valued digital data, and further generates a digital signal comprised of reference signal with constant amplitude and constant width in a maximum formed to be a prescribed cycle and a plurality of data signals expressing the multi-valued digital data between the reference signals, transmits a carrier wave about which the digital signals are used as modulation input. Then, the digital communication system, at a reception side, performs peak detection and makes the peak value of the amplitude at or below a prescribed amplitude value, uses a synchronous detection circuit in a demodulation circuit, performs peak detection again and makes the peak value of the amplitude the prescribed amplitude value, and in an envelope waveform of its modulation output compares the amplitude value of the reference signal of which peak value is reference of an amplitude value with an amplitude value at a designated place of respective data signals between the current reference signal and the next reference signal, determines the multi-valued number of the data signals, and demodulates the digital signal to the digital information data. |
