| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a frame synchronization protection controller and its method capable of achieving more stable frame synchronization protection. <P>SOLUTION: A state 3 is composed of a state 3(0, 0) to be a completely synchronized state in which synchronization is established and a forward protection state in which the other synchronization is established. In the state 3, the state is transited in accordance with a state transition diagram where the number of synchronization protection steps is "2" and the number of error protection steps is "2". A state machine 50 adds "1" to the number of synchronization protection steps when a synchronization decision signal is "NG", and adds "1" to the number of error protection steps when an error correction result signal is "NG". Then the state machine 50 calculates the number of forward protection steps which is the weighted sum of the number of synchronization protection steps and the number of error protection steps and compares the number of forward protection steps with a threshold to discriminate whether the number of forward protection steps is in a protection range or not. When the number of forward protection steps is in the protection range as the result of discrimination, the state is transited to a state corresponding to the present number of synchronization protection steps and the present number of error protection steps. When the number of forward protection steps is out of the protection range on the other hand, synchronization is canceled and the state is transited to a state 1. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
