| 摘要 |
PURPOSE:To take frame synchronization and bit synchronization even when some error takes place in a synchronous word by generating a same longest series code as that forming the synchronous word and taking correlation with the received synchronizing word. CONSTITUTION:A correlation device 1 takes correlation between an inputted serial code series and an M series code outputted from an M series generator 2 and outputs the result to a synchronization deciding circuit 3. The synchronization deciding circuit 3 compares a correlation voltage inputted from the correlation 1 with a reference voltage VF, decides that the synchronous word is detected and synchronization is taken when the correlation voltage is more than the reference voltage and outputs a deciding signal to a synchronization timing generating circuit 4. When an error takes place on a transmission line 11 or the like in a synchronous word part of the serial code trains inputted to the correlation 1, the correlation function between the synchronous word with a small error and the M series code outputted from the M series generator 2 is low but the resulting timing is identical, then the synchronization is taken. |
