A Low-Complexity SLM PAPR Reduction Scheme for Interleaved OFDMA Uplink

High peak-to-average power ratio (PAPR) of the transmitted signals is a major drawback of orthogonal frequency division multiple access (OFDMA) systems. The selected mapping (SLM) method is one of the major schemes employed for PAPR reduction. Unfortunately, the computational complexity of traditional SLM scheme is relatively high since a number of inverse fast Fourier transforms (IFFTs) are required. A low-complexity SLM PAPR reduction scheme is proposed in this paper for interleaved OFMDA uplink, where only one IFFT is needed. The proposed scheme exploits the interleaved mechanism and the time-domain signal property to construct a low-complexity architecture. The candidate signals are generated in time-domain by combining the original time-domain transmitted signal with its cyclic shift equivalents. The PAPR reduction performance of the proposed scheme is marginally poorer than that of the traditional SLM scheme. However, the proposed scheme achieves a substantially lower computational complexity.