| 摘要 |
PURPOSE:To process a demodulated base band signal digitally without any adjustment even if a clock frequency varies by generating a clock whose phase difference is held at a specific value by a clock generating means by using a control signal corresponding to the phase difference between the zero cross point of the demodulated base band signal and the change point of the clock. CONSTITUTION:A phase comparing means 7 extracts the output corresponding to the phase difference between the zero cross point of the demodulated base band signal and the change point of the clock and a control signal generating means 8 generates a control signal by using said output. then the frequency dividing operation of the clock generating means 9 for a reference clock is controlled with the control signal to generate the clock whose phase difference is held at the specific value. When the clock frequency varies, the frequency dividing operation corresponding to the variation is performed to perform the digital processing of the demodulated base band signal without any adjustment. |
