PAPR reduction by modified PTS combined with interleaving technique for OFDM system with QPSK subcarriers

Reduction of peak-to-average power ratio (PAPR) in orthogonal frequency-division multiplexing (OFDM) system using the partial transmit sequence (PTS) approach. In PTS, the total search for the number of subblocks and the rotation factors must be accomplished. As the number of subblocks and rotation factors increases, PAPR reduction improves. The number of calculation increases as the number of subcarriers increases, such that complexity increases exponentially and the process delay occur simultaneously. In this paper, a modified PTS scheme combined with interleaving technique for PAPR reduction has been presented. The scheme is very effective and avoids the use of any extra Inverse Fast Fourier Transformations (IFFTs) as was done in PAPR reduction by ordinary PTS technique when dividing the various subcarriers into different subblocks. The simulation result shows that PAPR performance is improved in comparison with the modified PTS and computational complexity is reduced.