Block SLM Scheme for Efficient PAPR Reduction in OFDM Systems

Abstract

Orthogonal frequency division multiplexing (OFDM) is an attractive technique due to its high-speed data transmission and robustness for time-selective channels. However, the major drawback of OFDM system is high peak-to-average power ratio (PAPR). In this paper, two PAPR reduction schemes have been introduced; one is conventional selected mapping (SLM) scheme and a new proposed block selected mapping (BSLM) scheme to obtain PAPR reduction performance in OFDM system. In the proposed BSLM scheme, OFDM symbol sequence was partitioned into several blocks and then each block sequence was multiplied with various phase-rotation sequences for generating alternative signals as candidates and then the one with the lowest PAPR was selected for actual transmission. Simulation result shows that proposed BSLM scheme provides a better PAPR reduction performance as compared to conventional SLM scheme, and it is also observed that by increasing the partition of blocks, large PAPR reduction can be obtained.