| 摘要 |
PURPOSE:To remove the deterioration in the transmission quality by timing jitter, by taking difference between the input and output signals of the peak detection circuit as the timing signal of identification circuit of bipolar signal and picking up the timing information near the peak position. CONSTITUTION:The bipolar waveform received from the input terminal 11 is equalized in waveform and shaped at the automatic equalizer 12 and control is made so that the peak value of the output waveform of the equalizer 12 can be constant by the control section 29. This peak value is detected at the peak detection circuit 15, and the difference between the input and output of the peak detection circuit 15 is picked up at the substraction circuit. The output of the subtraction circuit is fed to the digital phase control circuit as the input signal and it is compared with the reference voltage close to zero level to obtain the timing pulse in agreement with the timing phase near the peak value of pulse. Since less jitter presents near the peak value of the input bipolar signal, the timing pulse less in jitter can be obtained. Accordingly, the deterioration in the transmission quality due to timing jitter can be rejected. |
