| 摘要 |
<p>PURPOSE: To obtain an automatic frequency control method and a device to be used for the control of the local oscillation frequency by detecting a frequency offset between a carrier and a local oscillation signal from a receiver. CONSTITUTION: A phase difference detector 32 generates a 1st phase difference detection signal expressing a phase difference between the sampled signals as its phase value. A phase difference changing unit 34 generates a 2nd phase difference detection signal having a phase value different from the phase value of the 1st phase difference detection signal. Frequency offset signal generators 36, 38 estimate transmission phase information by using the phase value of the 2nd phase difference detection signal and the phase value of a reference phase signal to be used for MPSK modulation and generate a frequency offset signal determined by the transmission phase signal and the 2nd phase difference detection signal. The cost of hardware for an equipment to be practically produced can be reduced by changing the phase of a phase difference signal.</p> |
