a synchronism pattern detecting timing recorder records a synchronism pattern detecting timing at which a synchronism pattern is detected in reception data , a synchronism decider collates the reception data with reference data to decide whether or not the reception data is consistent in phase with the reference data , and a timing generator operates , when the synchronism decider gives a decision for inconsistency in phase , for a match between the synchronism pattern detecting timing recorded in the synchronism pattern detecting timing recorder , as a subsequent one , and a timing of a synchronism pattern of the expectation data , and the subsequent synchronism pattern detecting timing in record is used to render the phases consistent , allowing for a rapid synchronization to be obtained , without the need of waiting a detection of synchronism pattern , even with an inconsistency in phase due to a false synchronism pattern .