Performance Analysis of SLM Technique for PAPR Reduction in OFDM Using QPSK Modulation

Multi-carrier communication is a backbone of fourth-generation (4G) mobile communication due to high-data-rate capability. This multi-carrier communication is facilitated using orthogonal frequency-division multiplexing (OFDM). But high peak-to-average power ratio (PAPR) is a serious problem present in OFDM. High PAPR causes huge battery power consumption. To reduce PAPR, selected mapping (SLM) is one of the good technique from the set of scrambling methods. The performance of SLM technique for QPSK-modulated data with phase offsets of pi/4, pi/2, and 3 pi/2 using N=64, 128, 512, 1024, and 2048 number of subcarriers in MATLAB environment is presented in this article. PAPR results of original OFDM and OFDM with SLM technique are plotted and also presented in tabular form for comparison. We have also investigated the computational complexity of SLM scrambler and descrambler block using Freescale StarCore SC140 architecture simulator.