| 摘要 |
PROBLEM TO BE SOLVED: To prevent erroneous synchronism for multi-path phasing by switching a synchronizing signal from a detection edge into a pulse signal with a synchronism non-detection signal so as to execute demodulation. SOLUTION: A synchronism detection part 9 is connected to an edge detector 7 and a gate signal generator 8. When the edge is detected in a gate period, a synchronism detection signal is outputted. When the edge is not detected in the gate period, the synchronism non-detection signal is outputted. A switch 10 selected the output of the edge detector 7 and the pulse signal output of the gate signal generator 8. The output of the edge detector 7 is switched to the pulse signal output of the gate signal generator 8 with the synchronism non-detection signal of the synchronism detection part 9, and it is outputted to a demodulator 4 as a frame head. Namely, an operation load is reduced and erroneous synchronism is reduced since the judgment of pull-in is an operation at every frame synchronism. Thus, the precision of synchronism improves and the operation which is always stable can be obtained. |
