| 摘要 |
PROBLEM TO BE SOLVED: To propose a new method for enabling correlation processing over a correlation accumulation time longer than a bit length of navigation message data. SOLUTION: A correlation operation is performed for a received signal obtained by receiving a GPS satellite signal sent from a GPS satellite. Then, a frequency analysis using Fourier transform is performed for the results of the correlation operation over a correlation accumulation time equal to or longer than the bit length (20 ms) of the navigation message data carried by the GPS satellite signal. A power value exceeding a prescribed threshold "θ" among those obtained by the frequency analysis is extracted and added to the power value at frequency zero, while the extracted power value is made "0". After a correlation value is reconstructed by inverse Fourier transform, the reconstructed correlation value is accumulated and the GPS satellite signal is acquired on the basis of the accumulated correlation value. COPYRIGHT: (C)2011,JPO&INPIT
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