| 摘要 |
PURPOSE:To contrive to decrease the synchronization establishing time by adding a carrier recovery circuit multiplying a received carrier, frequency- dividing the result and extracting a carrier signal and applying pull-in based on the extracted carrier signal at the pull-in. CONSTITUTION:Most of recovered data DATAR are in error at the initial pull-in. Thus, a phase uncertainty elimination signal Sp representing a high error frequency of occurrence is outputted from an error correction decoder 200. In receiving the phase uncertainty elimination signal, a tracking control circuit 104 stops the tracking of a Costus carrier recovery circuit 101 and uses the recovered carrier CRR from a multiplication frequency division type carrier recovery circuit 105 to apply pull-in. The multiplication frequency division type carrier recovery circuit 10 multiplies a received carrier SIN by a prescribed multiple and frequency-divides it by its reciprocal to extract the carrier CRR, then the carrier CRR is extracted quickly. Since the pull-in is applied by using the carrier CRR without sweep operation, the quick pull-in is attained. |
