| 摘要 |
<p>PROBLEM TO BE SOLVED: To expand allowable range of an oscillation frequency to be mixed with a carrier frequency and to detect a correlation value peak in a short time. SOLUTION: A code synchronous circuit 13 of a demodulating device provided with a demodulation circuit 30, having a diffusion code generator 4 for a diffusion code which is the same as a diffusion code in a received signal, the code synchronous circuit 13 for the diffusion signal in the received signal and a generated diffusion code and an inverse diffusion circuit 14 for a received signal using a synchronized diffusion code, is also provided with correlators 3A and 3B taking a correlation value between the diffusion code in the received signal and the generated diffusion code. The correlators 3A and 3B consist of a division circuit for a diffusion code, which divides one cycle of a diffusion code into a plurality of parts in calculating a correlation value, an absolute value operation circuit for calculating the also lute value of the correlation value of each divided section and an addition circuit for adding the absolute value of each divided section for one cycle of the diffusion code. A carrier frequency generator 2 generates an oscillation frequency, matching with the carrier frequency of the received signal by observing the added correlation values.</p> |
