Receiving apparatus and receiving methods

摘要

A technique for receiving an OFDM signal is arranged to reproduce correct carriers. I channel data and Q channel data decomposed into subcarrier components by FFT processing are differential-demodulated by a differential demodulation circuit (803) to remove an FFT window phase error and a reproducing carrier phase error. In a further differential demodulation circuit (809), a reproducing carrier frequency error and a phase error dependent on a reproducing clock frequency error are removed and only I-axis data is thereafter output to be stored in a RAM (810) with respect to each symbol. A pilot signal selecting data generation circuit (811) supplies the RAM (810) with data which is prepared by suitably shifting pilot signal selecting data used as a reference. The resulting data read out is accumulated by cumulative addition performed by a cumulative addition circuit (813). A maximum value detection circuit (814) detects a maximum value of the output from the cumulative addition circuit (813), and the amount of shift of the pilot signal selecting data is stored in a reproducing carrier frequency error storage circuit (822). The reproducing carrier frequency error storage circuit (822) outputs the amount of shift corresponding to the maximum value.