| 摘要 |
PROBLEM TO BE SOLVED: To provide a synchronization detector and an error rate measurement device that can properly detect synchronization of a cycle period of a bit stream even when a communication channel has a high frequency of occurrence of errors. SOLUTION: This invention provides the synchronization detector where a transition condition from a forward protection state after a pattern hunt into other pattern hunt state or a synchronization establishing state is obtained by comparing a received bit stream with a reference bit stream. Nonmatching information denoting the comparison result is stored over prescribed N-periods with respect to a cycle period of the reference bit stream. First, when (N+1) sets of information sets are not nonmatching information over the cycle period with respect to nonmatching information being a comparison result at present and the prescribed N-sets of the nonmatching information of the same bit phase for the cycle period that are stored and correspond to the nonmatching information of the current comparison, it is discriminated that the synchronization is established and the state is transited to the synchronization establishing state, and second, when the nonmatching information takes place even once, it is discriminated that the asynchronization is detected and the state is restored to the pattern hunt state. |
