To extend a frequency lock range of AFC processing up to a multiple of ±1/4 of a symbol rate.

A correction data generating section 125 generates correction data on the basis of a polarity of a frequency offset discriminated by a polarity discrimination section 124. A synchronization word discrimination section 906 detects whether or not a synchronizing word detected from received decoding data is in error. When the number of consecutively erroneous times exceeds a threshold value, it is discriminated that estimate in the frequency offset is in error by a changeover control section 130, and the section 130 applies changeover control to a changeover switch 126 to give correction data to a TCXO control data generating section 127.