CHANNEL ESTIMATION DEVICE, FADING FREQUENCY DETECTION DEVICE AND DEMODULATION DEVICE

摘要

A CHANNEL ESTIMATION VALUE OF DATA SYMBOLS OF A DATA CHANNEL IS CALCULATED BY WEIGHTING AND AVERAGING PILOT SYMBOLS IN A PARALLEL TIME MULTIPLEXING METHOD. ALSO, A CHANNEL ESTIMATION VALUE OF DATA SYMBOLS DURING EACH DATA SYMBOL INTERVAL IS CALCULATED BY DIVIDING DATA SYMBOLS IN A SLOT INTO A PLURALITY OF DATA SYMBOL INTERVALS, SELECTING PILOT SYMBOLS SUITABLE FOR CALCULATION OF A CHANNEL ESTIMATION VALUE OF DATA SYMBOLS DURING EACH DATA SYMBOL INTERVAL AND WEIGHTING AND AVERAGING THAT PILOT SYMBOLS. ALSO, A FADING FREQUENCY IS DETECTED BASED ON AN INNER PRODUCT VALUE OF PILOT SYMBOLS. A CHANNEL ESTIMATION VALUE IS CALCULATED BY WEIGHTING AND AVERAGING PILOT SIGNALS USING PLURALITY OF WEIGHTING SEQUENCES. THE CALCULATED CHANNEL ESTIMATION VALUE IS USED TO DEMODULATE RECEIVED DATA. THE OUTPUT DATA WITH THE HIGHEST QUALITY IS SELECTED BY JUDGING RELIABILITY OF THESE PLURALITY OF DEMODULATED DATA. IT IS ALSO POSSIBLE TO SELECT SOME WEIGHTING SEQUENCES BASED ON THE RESULT OF THE RELIABILITY JUDGMENT OF THE DEMODULATED DATA FOR PREDETERMINED PERIOD OF TIME. AFTER THE SELECTION, DEMODULATION IS PERFORMED BY USING THESE SELECTED WEIGHTING SEQUENCES ONLY.