Research On The PAR Reduction Of An OFDM Signal Using PTS Method

In recent years, OFDM has seen rising popularity as a high-speed transmission technique which can provide greater immunity to ISI. OFDM has been successfully used in systems like ADSL, WLL, DAB, HDTV, WLAN and so on, and it will become a key technique in 4G mobile communication systems. However, OFDM has a drawback of high PAR in its application, which directly affects the performance of the whole system.In this thesis, the PAR problem and the PAR reduction techniques are researched. A low complexity PTS method was realized in the thesis and some improvements to the method were made. Through simulation, some comparisons among the PAR reduction performances and computational complexities of the conventional PTS method, the low complexity PTS method and the improved PTS method were made. The simulation results proved that the conventional PTS method had the optimal performance, but its computational complexity increased exponentially with the number of subblocks. The low complexity method had the lowest computational complexity but its performance was the worst. The improved method had a performance only 0.5 dB poorer than that of the conventional method and its complexity was greatly lower than that of the conventional method, which proved that the improved method can achieve good PAR reduction performance at low computational complexity.