Low-complexity PAPR reduction scheme without side information for OFDM systems

This paper proposes a novel peak to average power ratio (PAPR) reduction scheme that requires no side information in orthogonal frequency division multiplexing (OFDM) systems. Unlike the selective mapping (SLM) or the partial transmit sequence (PTS) scheme, the proposed scheme deals with post inverse fast Fourier transform (IFFT) symbols and thus requires only a single IFFT processor in the transmitter. Compared to other conventional schemes implemented with a single IFFT processor, such as the circularly shifted phase sequences (CSPS) or the optimised circularly shifted phase sequences (OCSPS) method, the proposed scheme achieves an even lower complexity since only phase rotation and cyclic shifting of OFDM symbols are performed. More importantly, the proposed scheme significantly outperforms the CSPS and the OCSPS methods in reducing PAPR as shown in simulation results. An added benefit of the proposed scheme is that it employs a linear receiver, such as a maximal likelihood (ML) detector, a minimum mean square error (MMSE) estimator, or a zero forcing (ZF) estimator, to demap quadrature amplitude modulation (QAM) symbols. Especially the ML detector demaps the QAM symbols with no side information. Simulation results also show that the bit error rate (BER) of the proposed scheme has no loss when the ML detector, the ZF or the MMSE estimator is used with hard-decision compared to that of the conventional OFDM system without any PAPR reduction scheme over Rayleigh fading channel.