| 摘要 |
PURPOSE:To accurately discriminate reception data by Fourier-transforming the output, which is filtered by a prescribed band, with a Fourier transforming means and extracting a specific spectrum of the transformation result and subjecting this spectrum to inverse Fourier transform. CONSTITUTION:The output of a BPF 407 is inputted and is subjected to fast Fourier transform. A maximum frequency spectrum is selected by a spectrum extracting circuit 409. Larger one of two spectrums adjacent to the maximum spectrum is selected, and two selected frequency spectrums are subjected to fast inverse Fourier transform by an IFFT 410 and the result is outputted to a DPLL 412. Since the BPF processing is performed before fast Fourier transform in this manner, a timing phase is satisfactorily extracted in case of fast Fourier transform though the Fourier transform processing is relatively easy. |
