| 摘要 |
PURPOSE:To obtain a system which is capable of detecting an additional information block synchronizing signal by the minimum increase of a circuit, and also has a high transmission efficiency, by setting a synchronizing signal to a different pattern by a transmitting block into which the head bit of an additional information block is insertd, and a transmitting block into which the head bit of the additional information block is not inserted. CONSTITUTION:A signal inputted from a data input terminal in the figure is inputted to synchronizing pattern detecting circuits 6, 6' and an additional information extracting circuit 1. The first synchronizing pattern detecting circuit 6 detects the first synchronizing signal pattern in an input transmitting signal, and the second synchronizing pattern detecting circuit 6' detects and outputs the second synchronizing signal pattern in the input transmitting signal. The two synchronizing pattern detecting signals are added by an OR gate 7, and are inputted to a main data synchronizing signal output gate 8. On the other hand, the output of the second synchronizing pattern detecting circuit 6' is inputted to an additional information block synchronizing signal output gate 10, and only the second synchronizing signal is outputted from the additional information block synchronizing signal output gate 10 exactly. |
