| 摘要 |
PURPOSE:To shorten a synchronous returning time by obtaining frame synchronization with utilizing the information of a synchronous position for a specified bit. CONSTITUTION:A specified bit G is arranged in each (s)-bit (the bit number of one block) in a frame with a purpose different from frame synchronizing bits F1-F4. Then, the specified bit G is in the position of N0/s in one frame during an N0 bit period F and an (r)-number of the frame synchronizing bits are wholly arranged just after the specified bit G. Such a receiving code sequence is inputted to a block synchronizing circuit 7 and the block synchronization is obtained concerning the specified bit G. The frame synchronization is continuously obtained, however, at such a time, the noticed bit is only the bit just after the specified bit G enough. When the noticed bit and frame synchronizing bit are not coincident, the shift of one block, namely, the shift of (s) bit is executed. Thus, a frame synchronizing position is reached only by the (N0/s-1) number of the (s) bit shift and the synchronous returning time is shortened. |
