PAPR Reduction in OFDM System with π/4-QPSK Mapper Using Improved PTS Technique

Abstract

An Orthogonal Frequency Division Multiplexing (OFDM) system with π/4-QPSK (Quadrature Phase Shift Keying) mapper is considered. Partial Transmit Sequence (PTS) technique with an improved partitioning technique is proposed for PAPR reduction. Even though in PTS, the pseudo-random partitioning method yields the best PAPR reduction compared to adjacent and interleaved partitioning methods, there is a lack of structure in partitioning and hence increases system complexity both in the transmitter and the receiver. The proposed scheme offers a systematic and simple construction of adjacently partitioned sub-blocks using the Magic squares to pseudo-randomize them. Numerical results show that the proposed method outperforms both the adjacent and the interleaved partitioning methods and has nearly the same performance as that of pseudo-random partitioning method. 