| 摘要 |
<p>PURPOSE:To obtain a spread code acquisition circuit with high detection probability and excellent accuracy by calculating the degree of random transition of a phase difference of a carrier with respect to each code phase and using the result of calculation. CONSTITUTION:An input received signal is converted into two base band signals by two orthogonal carriers, and the correlation between the two base band signals and the received signal series is obtained by two correlation means 10, 11. Then a code acquisition means adds the square sum of the output of the correlation means 10, 11 with synchronization to acquire the code and the carrier phase difference between the received signal and the local signal is calculated from the correlation value of the output of the two correlation means 10, 11. Then the degree of random timewise transition of the carrier phase difference is calculated from several periods of the calculated carrier phase difference by an arithmetic means, and a deciding means 17 applies code acquisition decision based on each output of the code acquisition means and the arithmetic means. Thus, the spread code acquisition with short code acquisition time and excellent code detection probability and detection accuracy is obtained.</p> |
