| 摘要 |
PROBLEM TO BE SOLVED: To lock its frequency to a desired local frequency quickly at a control speed depending on the deviation of the local frequency even when noise (deteriorated C/N) becomes large at demodulation of a received PSK wave. SOLUTION: This controller is provided with a means 6 extracting only phase shift quantity information only to process separately phase shift data for the quantity of phase shift and a direction of the phase shift, a means 8 averaging only the quantity of phase shift, a means 7 extracting only information of phase shift direction and a means 9 taking majority decision of the phase shift direction information only and selecting a majority direction. The frequency of a local frequency generating section is controlled according to the mean value and the majority decision. Thus, even when the C/N is deteriorated, the frequency is controlled at a speed corresponding to the magnitude of the local phase shift. |
