| 摘要 |
<p>PURPOSE:To normally detect a carrier independently of the deterioration in the characteristic of a transmission line by discriminating it to be detection of a carrier when a peak is observed m-times for N periods in any of plural areas divided in one period of a code series in the carrier detection of the CSK modulation system. CONSTITUTION:The apparatus is provided with a peak position detection circuit 26, a peak position discrimination circuit 27, a counter circuit 28 and an m/N discrimination circuit 29. The peak position detection circuit 26 detects the correlation peak position of a correlation signal between a reception signal and a code series of a prescribed code length for one period each of a code series over 1st prescribed number (N) periods to be consecutive at most and discriminates to which area the peak position detected by the peak position discrimination circuit 27 belongs among areas of plural the number to be divided in one period. The counter circuit 28 counts the number of detected peaks belonging to the area each and the m/M discrimination circuit 29 discriminates whether or not the detection peak count in any area for the 1st prescribed number (N) periods at most reaches the 2nd prescribed number (m) and outputs a carrier detection signal when the count reaches the number (m).</p> |
