| 摘要 |
PURPOSE: To surely demodulate a multilevel modulation symbol on a reception side even at the time of receiving the influence of phading, to reduce the transmission amount of reference data and to improve data transmission efficiency. CONSTITUTION: At the time of generating and transmitting an OFDM transmission frame in this transmitter, a null symbol and a reference symbol are arranged only in the leading part of the frame, QPSK symbols are arranged in a fixed interval respectively in a time direction and a frequency direction in an information symbol data area and transmission is performed. On the other hand, in this receiver, the amplitude error and phase error of respective carriers are detected by the reference symbol arranged in the leading part of the transmission frame, the amplitude fluctuation and phase fluctuation of reception waves are detected by the respective QPSK symbols and the amplitude error and the phase error of the respective carriers detected by the reference symbol are corrected based on the detected result. Then, based on the corrected amplitude error signals and phase error signals, demodulation symbol data are equalized.
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