PAPR reduction of the low complexity phase weighting method in OFDM communication system

Orthogonal frequency division multiplexing (OFDM) has been used in many communication systems. However, the major drawback of OFDM system is high peak-to-average-power ratio (PAPR). In this paper, we introduce low complexity phase weighting method to reduce PAPR of OFDM signals. Proposed method is derived from property of discrete Fourier transform (DFT) of periodical sequences. PAPR can be reduced efficiently by phase weighting method with low complexity. The simulation results show the same PAPR reduction efficiency of proposed method in comparison with partial transmit sequence (PTS) or sub-block phase weighting (SPW). The proposed technique can reduce 2.15 dB of PAPR with two phase-factors and 3.95 dB of PAPR with four phase-factors. The analysis on complexity presents remarkable improvement of low complexity phase weighting method. Proposed method odd case can save 75% and 87.5% number of multiplications of PTS method and SPW method separately. The other case of proposed method, even case, can save near 60% number of additions of PTS and over 70% of SPW.