An Improved SLM Algorithm for Reducing PAPR in OFDM System

SLM (Selected Mapping) is an effective algorithm to reduce Peak to Average Power Ratio in OFDM (orthogonal frequency division multiplexing) signal without distortion. However the SLM scheme needs to dispose U paths of IFFT(Inverse Fourier Transform), which increases the computational burden and reduces the signal transmission rate. This article offers an improved algorithm that based on SLM, which is named Random Screening SLM (RS-SLM). The proposed algorithm executes the selection before the IFFT module. and only selects one sequence with the highest randomness to be transmitted according to the offset. Because only one path of signal is transmitted in IFFT modules, the proposed algorithm has lower complexity compares with SLM. Moreover, it has advantages in enhancing the signal transmission rate and decreasing the PAPR of OFDM signals.