| 摘要 |
PURPOSE:To regenerate the synchronization of a carrier wave, by transmitting a burst wave consisting of a constant number of waves as a pilot signal from the transmission side and by counting the number of waves of the burst wave of this signal to control a local oscillator in the receiving side. CONSTITUTION:A pilot PL signal from a PL oscillator 1 in the transmission side is converted to a burst signal by a switch 4 and is synthesized with an input signal by a hybrid 5 and is subjected to frequency conversion in a circuit 7 and is transmitted through a BPF8. In this case, the number of waves of the burst wave of the PL signal is counted by a counter 2, and the switch 4 and the counter 2 are so controlled by a timing circuit 3 as to count surely a prescribed number of waves. In the receiving side, a receiving signal is subjected to frequency conversion in the circuit 7 by a local oscillator 10 and passes through a BPF9, and the PL signal branched by a hybrid 11 is inputted to a control circuit 26 through a BPF13. The circuit 26 calculates the difference between the number of waves of the PL signal counted by a counter 13 and the number of waves preliminarily set in the transmission side by a circuit 15. This difference is latched in a circuit 16 and is subjected to D/A conversion in a circuit 17 and is applied to the oscillator, and the oscillator is so controlled that the difference becomes 0. |
