| 摘要 |
<p>PURPOSE:To set number of times of protection in an excellent way and to take synchronization quickly again when out of synchronism takes place. CONSTITUTION:An intermediate frequency signal and a pilot signal Sp are fed to a reception state discrimination section 21, which discriminates the reception state. When the reception state is excellent, number of times of forward protection of a forward protection counter 11 is set small and number of times of backward protection of a backward protection counter 12 is set large. On the other hand, when the reception state is not excellent, number of times of the counters 11, 12 is set reverse. Moreover, an error correction circuit 9 gives a signal to a correction disable data counter 22, which counts number of correction disable data. When number of correction disable data exceeds a prescribed value, the operation of a synchronization reproduction section 13 is stopped independently of the state of the forward protection counter 11 to set an asynchronous state and the operation of synchronization enters again. Even when number of times of forward protection is set large, when out of synchronism takes place, the synchronization is quickly taken.</p> |
