| 摘要 |
PROBLEM TO BE SOLVED: To easily operate a conversion frequency for orthogonal detection at an optional frequency and to realize miniaturization of the receiver at a low cost. SOLUTION: A signal obtained by converting a reception signal into an intermediate frequency band signal at an analog section 10 is sampled by an A/D converter 201, which converts the signal into a digital signal. The digital signal is orthogonally detected by multiplying an output signal of a numerical controlled oscillator 203 controlled by an automatic frequency control circuit 210 with the digital signal at multipliers 202A, 202B of a digital orthogonal detection section 202. harmonics of the detected signal are eliminated at low pass filters 204, 205 and re-timing is taken at a sampling rate being an integer multiple of a symbol rate by a re-sampling circuit 206 controlled by a clock phase signal from a synchronization detection demodulator 209. The re-timing signal is subject to spectral shaping at reception filters 207, 208, demodulated at a synchronization detection demodulator 209, from which demodulation data are outputted. |
