| 摘要 |
PROBLEM TO BE SOLVED: To highly precisely and casily detect a preamble for synchronizing timing/carrier frequency using a short symbol by Fourier-transforming the output of a symbol synchronism processing circuit, separating the result into signals for respective sub-carriers and executing demodulation for the respective sub- carriers from the output of FFT. SOLUTION: A Fourier transformation circuit (FFT) 6 Fourier-FFT transforms the output signal of a synchronous circuit 5 and separates an OFDM modulation signal into signals for respective sub-carriers. A transmission line distortion estimation circuit 7 receives the signals separated for the respective sub-carriers from FFT 6 and estimates a transmission line characteristics at the time of receiving a preamble for estimating transmission line. The transmission line distortion estimation circuit 7 outputs a count for compensating transmission line to a transmission line distortion compensation circuit 8 according to the estimated result. The transmission line distortion compensation circuit 8 receives the signals separated for the respective sub-carriers, and multiplies a count for compensating transmission line distortion by a complex so as to compensate transmission line distortion. A sub-carrier demodulation circuit 9 executes demodulation for the respective sub-carriers. |
