| 摘要 |
PURPOSE:To improve S/N, by transmitting an optical pulse from one end of an optical cable, photoelectric-converting a reflecting signal reflected in the cable and returned, and adopting the two-stage constitution of a simple addition and averaging processing means and an exponential weighting and averaging processing means for the reflecting signal. CONSTITUTION:A repetitive signal including noise is amplified suitably at an amplifier 1 and inputted to an AD converter 2. The AD converter 2 performs n- set of AD conversion as to one period T of the repetitive signal. Further, the highest averaging processing is performed at the simple addition and averaging processing section within the range of the amount of S/N improvement and the deficiency of the amount of S/N improvement is compensated at the exponential weighing averaging processing section 6 at the next stage in the circuit constitution. |
