| 摘要 |
PURPOSE:To simplify a procedure to establish synchronization and to shorten a time required for the establishment of the synchronization, by making a multiple frame synchronization establishing procedure subordinate to a basic frame synchronization establishing procedure, and holding multiple frame synchronization after establishing the multiple frame synchronization except for the case where the step out of a basic frame is generated. CONSTITUTION:Either synchronizing words F1-Fn is retrieved from a reception signal string to obtain the synchronization of the basic frame. In such a case, a present state is kept when the synchronizing word in the repeating period TBF of the basic frame is detected. When the basic frame synchronization is established in such a way, the combination of the synchronizing words is retrieved, and a preset protection frequency is counted up. When a protection condition is established, it means that the synchronization of the multiple frame is established. When the step out of the basic frame is generated, a procedure is returned to a first step. |
