| 摘要 |
PURPOSE:To demodulate a phase modulation signal without receiving a carrier signal from the transmission side by detecting a phase difference between a carrier of an input signal and a fixed oscillator output. CONSTITUTION:A phase detector 1 consists of a fixed oscillator 10 outputting a frequency set far closely to a transmission carrier, a complex number multiplier 11 and a complex number low pass filter so as to detect a phase difference. An accumulated circuit 3 consists of a circuit 30 generating a time from the sampling start until a prescribed sample value of a sample circuit 2 and of a phase fluctuation detector 31. Then an average value is obtained by an average circuit 4 and a phase difference estimation circuit 5 obtains an estimated sample value. A phase difference absorbing circuit 7 applies phase rotation to correct the carrier phase error. |
