The Research On PAPR (Peak-to-Average Power Ratio) Reduction Techniques In OFDM Systems

The PAPR in OFDM systems is discussed particularly in this paper. Detailed research and MATLAB performance simulation analysis are done on some existing classical algorithms, based on which two new algorithms reducing the PAPR of the systems are proposed.A novel iterative clipping algorithm based on predistortion clipping techniques is proposed to reduce the PAPR of OFDM signals. This method uses iterative clipping and builds corresponding Search Table, then recovers the clipping amplitude via the Search Table at the receiver, so it reduces greatly the impact of clipping noise to the BER performance of the systems. The simulation results show that the proposed algorithm can reduce well the PAPR of OFDM signals and eliminate the effect of clipping noise deteriorating BER performance.An improved PTS method based on classical PTS algorithm and suboptimal-PTS algorithm is proposed. This method brings in the Search Principle based on Hamming Distance, according to which controls the number of phase coefficient factor needed to be changed in each iteration step, so it can well control the computation complexity of the algorithm; By choosing the proper number of phase coefficient factor needed to be changed, it can make a choice or optimization between the computation complexity and the PAPR performance. The computation complexity of this proposed algorithm is greatly reduced compared with the classical PTS algorithm, and the better PAPR performance is provided in contrast to the suboptimal-PTS algorithm. In other words, the proposed algorithm obtains a compromise processing performance between the classical PTS algorithm and the suboptimal-PTS algorithm.