| 摘要 |
PURPOSE:To enable the decision of high accuracy even when a DC component is not transferred to a demodulation signal by generating a signal corresponding with the positive/negative character of phase difference and a signal corresponding with the size of the phase difference, and controlling a discriminating and deciding reference voltage using these two signals. CONSTITUTION:A comparator 1 converts an input signal (a) to a digital pulse signal (c) of 1 or 0 and a leading edge detection circuit 2 detects only a leading edge point and a bit synchronizing circuit 3 reproduces a synchronizing clock from the data. Also, a trailing edge detection circuit 4 detects only the trailing edge point of the input signal (a) and a bit synchronizing circuit 5 reproduces the synchronizing clock from the data. The phase difference and the size of synchronizing clocks (d) and (e) which are reproduced respectively at both of the bit synchronizing circuits 3 and 5 are f-detected and g-detected and a D/A converter 7 controls the discriminating and deciding reference voltage of the comparator 1 so as to decrease the phase difference detected at a phase difference detection circuit 6. |
