| 摘要 |
PURPOSE:To eliminate the mis-detection of a correlation pulse by applying peak hold to each spike level independently and generating a threshold value independently based thereupon when there is a level difference between positive and negative correlation spike levels of correlation output. CONSTITUTION:The output data (i) of a latch circuit 8 is given to a threshold value setting circuit 12, where the output data (i) of the latch circuit 8 and a control signal (k) representing a multiplication coefficient are calculated and a threshold level (l) is generated. The threshold level signal (l) is an N-bit digital signal. Then the threshold level signal (l) obtained by the threshold level setting circuit 12 is given to a comparator 14, which compares the output (c) of an A/D converter 2 with the threshold level (l) and an output (j) is obtained when the output (c) of the A/D converter 2 larger than the threshold level (l) is inputted. Since the correlation pulse (j) corresponding to the correlation spike is obtained, the mis-detection of a correlation pulse even when there is a level difference between the positive and negative correlation spike levels of correlation output. |
