| 摘要 |
PURPOSE: To reduce an error rate of a demodulation circuit without increasing a circuit scale by using a waveform conversion circuit to convert a carrier component of a received n-phase PSK modulation wave into a rectangular wave with a required duty factor. CONSTITUTION: A carrier component of an n-phase PSK modulation wave via a BPF 11 is given to a waveform conversion circuit 12, in which the carrier component is converted into a rectangular wave whose duty factor is 50% or over or below and the wave is latched at a latch circuit 13 based on a clock signal whose frequency is an integer multiple of a frequency of the carrier signal. Then an output of the circuit 13 is delayed by a shift register 14 and a phase difference between a latch output and a delay output is detected by exclusive OR circuits 16, 15 and identification recovery circuits 18, 17 detect and demodulate the n-phase PSK modulation wave based on the phase difference. |
