| 摘要 |
PROBLEM TO BE SOLVED: To provide a radio communication system, and a transmitter and a receiver used therefor such that the peak-to-mean power ratio of an OFDM signal is lowered by controlling a subcarrier phase and the receiver side can estimate a phase controlled variable without using control information. SOLUTION: The peak-to-mean power ratio of a turbo encoded OFDM signal is lowered by multiplying a subcarrier to which an inspection bit is allocated by a weight coefficient of 1 or -1. A turbo decoder on the side of the receiver is equipped with element decoders, which each compares an absolute value mean of an external value found by a MAP decoder to estimate a weight coefficient. Only an external value judged to be high in reliability is used as pre-information of other element decoders to perform repeated decoding. Here, the weight coefficient is determined when estimated values of weight coefficients are all equal among the element decoders or when the prescribed number of times of repetition is reached. After the weight coefficient is determined, conventional turbo decoding (repeated decoding) is carried on. COPYRIGHT: (C)2007,JPO&INPIT
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