A serial concatenation of coding and trellis shaping for OFDM systems with peak power reduction

Orthogonal frequency-division multiplexing (OFDM) can achieve remarkable performance in terms of spectral efficiency. However, its well-known drawback is that the OFDM signals have high peak-to-average power ratio (PAPR), and this causes performance degradation in terms of power amplifier (PA) efficiency. Trellis shaping (TS) is an effective method to reduce PAPR without signal distortion by exploiting the trellis structure at the transmitter. In practice, OFDM should be combined with channel coding in order to achieve frequency diversity. In this paper, we propose a serial concatenation of channel coding and trellis shaping such that the frequency diversity effect and peak power reduction can be simultaneously achieved. A novel BCJR-based LLR metric calculation for trellis shaping bits is introduced for this purpose. The effectiveness of the proposed approach is confirmed by simulation over AWGN and frequency-selective fading channels.