Block coded modulation for the reduction of the peak to average power ratio in OFDM systems

In this paper, we propose a block coded modulation (BCM) technique to reduce the peak to average power ratio (PAPR) in OFDM systems. In the proposed technique, binary blocks are mapped to M-ary blocks and M-ary blocks of small sizes with low PAPR are selected. Large size M-ary blocks with low PAPR are constructed by using the selected small size M-ary blocks. Similar to trellis coded modulation, with this technique variable rates ranging from 1 to a rate much higher than 1 of BCM can be obtained upon different requirements of the random error correction capability in the system, given that the PAPR is below a fixed value. PAPR gain is defined by comparing with the uncoded OFDM system. Optimal coding gain for the BCM given a PAPR gain is also obtained in various cases