Research of Peak-to-Average Power Ratio Reduction Improved Algorithm for MIMO-OFDM System

MIMO-OFDM system has the same defect as OFDM system, that is it has a high PAPR, which means when the signal pass through the non-linear power amplifier and other devices, it would require the amplifier has a wide dynamic range, otherwise, it would have a non-linear distortion, the generated harmonics will cause interferences among the sub-channels, finally it leads the signal distorted in interactive modulation and the system performance declined. On the basis of study the existing type of PAPR reduction algorithm applying the highly complex calculation probability, this paper proposes an algorithm of partial transmit sequence with the multi-antenna cooperative working by proving the strict corresponding conjugated relationships between weight vectors on the double antennas in the partial transmit sequence algorithm. This algorithm applies the partial transmit sequence algorithm to the OFDM system which uses space-time block coding. The simulation results show the improved algorithm can effectively reduce the PAPR and the calculation, it has great practical values.