| 摘要 |
PROBLEM TO BE SOLVED: To acquire more surely a signal having a prescribed frequency, even when a clock signal whose frequency is fluctuated with elapse of time is used. SOLUTION: A GPS signal reception part 104 acquires a GPS signal based on a GPS clock signal generated from a clock generation part 106 for GPS. A search frequency control part 109 controls a search object frequency of the GPS signal reception part 104 based on a frequency corresponding to reference correction information. A frequency comparison part 107 outputs a frequency difference with an ideal value of the frequency of the GPS clock signal. A clock frequency estimation part 122 discriminates a variation state of the frequency of the GPS clock signal based on a plurality of frequency differences at different times, estimates the frequency of the GPS clock signal at each time, and adjusts the reference correction information for correcting the search object frequency so that a search range of a GPS reception part 217 becomes an ideal frequency band. COPYRIGHT: (C)2007,JPO&INPIT
|
