摘要 |
<p>PURPOSE: To provide a synchronous tracking device which never deteriorates its tracking precision even when the fading speed of a received signal is increased. CONSTITUTION: A synchronous tracking part 12 detects the phase difference between a demodulating PN code C1 and a PN code included in a received signal by an autocorrelation operation and controls the phase of the code C1 based on the detection output of the phase difference. A maximum Doppler frequency detection part 14 detects the maximum Doppler frequency of the received signal. A correlation length control part 15 controls the operation range (correlation length) of the autocorrelation operation of the part 12 based on the maximum Doppler frequency detected at the part 14.</p> |