High-rate OFDM codes for peak envelope power reduction and error correction in MQAM systems

We describe a new coding technique that reduces the peak envelope power ratio (PEPR) and corrects errors in MQAM-OFDM systems. By introducing M-ary phase-shift-keying (MPSK) partitioning, we explain the design of hybrid codes having these two properties for MQAM-OFDM. Our technique is simply based on the phase difference between subset carriers and reduces, with very low redundancy, the PEPR of OFDM signals by means of the frequency-domain interleaving of code subsets. By using the MQAM-OFDM signal model, including the amplitude/phase error due to MPSK partitioning, our theoretical analysis of the PEPR performance gives tight upper bounds for any modulation scheme. We also discuss the trade-off between the PEPR reduction and the coding rate when the code length is expanded