| 摘要 |
PURPOSE:To suppress phase jitter optimizingly by comparing plural output waves respectively used for plural modulation waves and recovered carriers to obtain a phase difference, separating the output waves into a common phase difference component and a phase difference component proportional to the plural output waves, revising the frequency of the plural output waves at each phase difference component so as to recover the carrier of each PSK modulation. CONSTITUTION:Outputs of PSK waves 111-113 having a modulation component and of VCOs 15, 16 are combined 17 to obtain outputs 121-123. The phases of them and the input waves 111-113 are comapred 11-13. The modulation component of the 4-phase PSK modulation wave is elimianted by the comparators 11-13 and a prescribed phase difference is obtained from outputs 114-116. Then two kinds of phase difference basic components are obtained from a prescribed equation, the difference is made within pi/4 and averaged, and the result is inputted 117, 118 to the VCOs 15, 16. The VCO varies the frequency continuously in a direction cancelling the detected 11-13 phase difference and a combiner 17 uses the outputs 119, 120 of the VCOs to recover the carriers 121-123 of each PSK wave. Through the constitution above, the phase jitter due to the noise in the PSK modulation wave is blocked. |
