| 摘要 |
PROBLEM TO BE SOLVED: To reduce the characteristic deterioration by making a center frequency of a received signal match with a center frequency of a matching filter. SOLUTION: A digital filter 8 is made to an adaptive filter variable in a band width which the band with can be controlled by a control signal 66 from a microcomputer 63, the band width is set in an extended state in the initial state of channel selection, to eliminate the deterioration in a demodulation characteristic caused by a carrier near to one end reaching a shoulder of a pass band of a digital filter 8. Then, the both outputs of a synchronous reproduction circuit 9 and an FFT circuit 10 are inputted to a frequency error detection circuit 54, where an error (df) between the center carrier of an OFDM signal and a center frequency of the digital filter 8 is detected and the error signal is fed back to an oscillation circuit of a tuner section 2, via the microcomputer 63 to move the OFDM carrier to the center of the frequency band of the digital filter 8. |
