METHOD AND DEVICE FOR PROTECTING DETECTION OF SYNCHRONOUS DETECTION CODE AND METHOD AND DEVICE FOR PROTECTING DETECTION OF ID NUMBER

摘要

PROBLEM TO BE SOLVED: To prevent IDs from being interpolated with erroneous values when erroneously detecting consecutive IDs due to off-track or the like and to shorten the time required for detecting a synchronous detection code again in the case that a frame position is deviated during protective detection using a window not to be able to detect the synchronous detection code after settlement of the frame position in a sector. SOLUTION: The sequentiality of detected IDs and the result of IED error check is monitored, and erroneous ID interpolation caused by off-track is prevented on the basis of two detection results. A second synchronous detection code detecting system is operated independently of a first synchronous detection code detecting system which is operated after settlement of a frame position in a sector, and the second synchronous detection code detecting system is used to correct the first synchronous detection code detecting system performing erroneous protective operation, and thus the window occurrence position of the first synchronous detection code detecting system is returned to a correct value to shorten the time required for detecting the synchronous detection code again.