A Comparative Study of Coded Multi-Carrier Systems over High-Mobility Channels

In high-mobility scenarios, coded multi-carrier modulation (MCM) schemes are resistant to the severe effects of Doppler shifts and have significant implications for reliable communication systems. Since channel coding has received limited attention in prior MCM waveform studies, this paper presents a comparative study of several coded MCM schemes. To this end, we propose an iterative receiver based on the orthogonal approximate message passing (OAMP) framework, which combines the linear minimum mean square error (LMMSE) estimator and the decoder. Simulation results reveal that channel coding enhances overall performance and narrows the gap among different modulation schemes. With the proposed detector, affine frequency division multiplexing (AFDM) outperforms other schemes in the low SNR region while interleaved frequency division multiplexing (IFDM) performs better in the high SNR region. Furthermore, we analyze the effect of symbol interleaving on coded MCM systems. Simulation results also show that, with the proposed receiver, these interleaved coded schemes yield a BER improvement of approximately 0.5 dB over conventional schemes. Among these systems, the interleaved AFDM achieves the best performance.