PAPR Reduction in OFDM Systems Using Modified SLM with Different Phase Sequences

Abstract

High Peak-to-average power ratio (PAPR) is one of the main issues in multicarrier modulation systems. PAPR is mainly caused due to the summation of various signals having high amplitude values. Several PAPR reduction techniques were employed, out of which Selective Mapping (SLM) proved to be one of the most effective schemes. Some drawbacks in SLM technique are high computational complexity and phase search complexity. Selection of phase sequences in SLM plays a major role in the reduction of PAPR as well as the computational complexity. Modified SLM was introduced to reduce computational complexity in SLM technique. In this paper, we apply various phase sequences such as Riemann, Centering, Centered Riemann and New Centered to Modified SLM technique and their effect on PAPR reduction are analyzed. From the simulation results, it can be inferred that the modified SLM with New Centered scheme achieves a significant PAPR reduction of the range 8.3–9.3 dB with respect to Conventional OFDM and 3–5.5 dB with respect to Conventional SLM technique. The Modified SLM-New Centered scheme is most suitable for 64-QAM applications as it provides good PAPR reduction performance at lower computational complexity.