| 摘要 |
PURPOSE:To obtain a carrier synchronization and a clock synchronization from an information signal. CONSTITUTION:The demodulation symbol from an FET circuit 33 is inputted in a constellation analysis circuit 45. The constellation analysis circuit 45 analyzes the constellation of the demodulation symbol of the lowest or the highest frequency carrier, for instance. When the constellation rotations of these demodulation symbols are in the same direction, it is judged that the frequency deviation of a reproduction carrier is generated, the frequency of the reproduction carrier is controlled based on the rotations by an carrier phase control circuit 46 and an AFC control circuit 47 and a carrier synchronization is obtained. When the directions of the constellation rotations of two demodulation symbols is in a reverse direction, it is judged that the frequency deviation of a reproduction clock is generated and the reproduction clock frequency is controlled by a clock control circuit 50. Thus, the carrier synchronization and the clock synchronization are obtained from only an information signal. |
