| 摘要 |
PURPOSE: To provide an automatic frequency control circuit with which a correct offset frequency is estimated by removing fluctuation caused by a transmissive data pattern contained in a power spectrum even concerning a noisy received signal. CONSTITUTION: This circuit is provided with the plural pairs of correlators 5 composed of arithmetic filters 3, with which only the fixed frequency width decided from the characteristics of respective transmission filters are passed corresponding to a storage circuit for storing a reference having the characteristics of the transmission filters and the reference of the power spectrum of the inputted received signal and the output of the storage circuit, and arithmetic circuits 4 for calculating the correlation of respective arithmetic filter outputs corresponding to the received signal and the reference. The offset frequency of the received signal is estimated by the plural pairs of correlators 5. |
