| 摘要 |
A communication apparatus includes a Doppler shift amount calculation unit configured to calculate a Doppler shift amount of a reception signal which is obtained by modulating a signal, for which spectrum spreading is performed by using a predetermined spread code, by a predetermined carrier frequency, a frequency shift amount setting unit configured to set a frequency shift amount on the basis of the Doppler shift amount, a frequency conversion unit configured to shift the frequency of the reception signal by the frequency shift amount, a coherent addition unit configured to perform coherent addition of the reception signal, a spread code generation unit configured to generate a spread code, and a phase detection unit configured to perform correlation calculation between a calculation result of the coherent addition and the spread code and detect a phase of the spread code of the reception signal on the basis of the correlation calculation result. |
| 主权项 |
1. A communication apparatus, comprising:
a Doppler shift amount calculation unit configured to calculate a Doppler shift amount of a reception signal which is received from an artificial satellite and is obtained by modulating a signal, for which spectrum spreading is performed by using a predetermined spread code, by a predetermined carrier frequency; a frequency shift amount setting unit configured to set a frequency shift amount for shifting a frequency of the reception signal on the basis of the Doppler shift amount calculated; a frequency conversion unit configured to shift the frequency of the reception signal by the frequency shift amount set; a coherent addition unit configured to perform coherent addition of the reception signal, the frequency of which is shifted; a spread code generation unit configured to generate a spread code; and a phase detection unit configured to perform correlation calculation between a calculation result of the coherent addition and the spread code generated and detect a phase of the spread code of the reception signal on the basis of a result of the correlation calculation, wherein the frequency shift amount setting unit updates the frequency shift amount one or more times on the basis of the Doppler shift amount from when the coherent addition is started until the coherent addition is ended.
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