Abstract: The problem of the practical orthogonal frequency division multiplexing (OFDM) system is that the peak to the average power raito (PAPR) is very high. This paper briefly describes the progress researches on reducing the PAPR. The method to reduce the PAPR of the OFDM system based on block coding modulation (BCM) is presented and the construction of large sub carrier number systems is proposed. We have analyzed the implementation principle and carried out computer simulation. The results indicate that the BCM method not only can effectively lower the PAPR in the OFDM system, but also carry out forward error correction (FEC).

Key words: block coding modulation (BCM), orthogonal frequency division multiplexing (OFDM), peak to average power ratio (PAPR)