| 摘要 |
PURPOSE:To discriminate a low-order group signal at the reception signal although it is cut off and at the same time to set the staff factor at 1 at that time point to always insert a staff pulse, by converting a part of the consequetive staff designating pulses into a repetitive pattern of m-bit continuous 1 and 0 through a small-scale circuit. CONSTITUTION:A channel input part 1 and a staff control part 2' are provided to a multiplexing device at the transmission side. The part 2' includes an AND circuit 24, a staff designating pulse generating circuit 9, a staff designating pulse inserting circuit 10' and a staff inserting circuit 11. The clock phase difference of a low-order group signal sent from a phase comparator 7 of the part 1 and a detection signal sent from an input cutoff detecting circuit 6 are applied to the circut 24 of the part 2'. The circuit 24 obtains a logic between the output of the circuit 6 and the phase difference of the comparator 7, and the logic is applied to the circuit 9. Then the successive staff designating pulses are used to transfer the information, and a repetitive pattern of continuous 1 and 0 is obtained. Thus the low-order group signal can be detected at the reception side despite cuttoff of said group signal. At the same time, the staff factor is set at 1 at that time point. Thus the staff pulse is always inserted. |
