| 摘要 |
PURPOSE: To discriminate and decide the burst signals of all levels of continuous inputs by adjusting the holding time setting of threshold voltage before and after the recognition of the head location of the first burst signal when the reception expected phase of a burst signal is not established. CONSTITUTION: When a synchronizing circuit 4 does not have a synchronization pattern detection when the reception expected phase of a burst signal is not established, hunting information f is outputted as the meaningless signal showing asynchronization. Therefore, an AND circuit 6 does not output an ATC (automatic threshold control) reset signal j by masking the reset signal h of a counter 5. As a result, threshold voltage c is determined from the reception level of the burst signal inputted in an ATC circuit 7, and continuous 0 sustaining time is shortened by shortening this holding time. Therefore, the voltage c drops up to an offset level in the asynchronous state till the input of the first burst signal, a discrimination circuit 2 is capable of discriminating and deciding a 0-1 pattern, regardless of the level of the first input burst signal and is capable of surely discriminating and deciding the subsequent synchronization pattern and main data. |
