A novel PAR reduction approach for OFDM system

OFDM (orthogonal frequency multiplexing) is one of the key techniques of next generation high rate communications system. High PAR (peak-to-average power ratio) of the transmitted signal is a principle drawback of the OFDM systems. This letter presents a novel PAR reduction method, called IPR (interleaving and phase rotation) that achieves significant PAR reduction. The IPR approach uses V-1 interleavers to produce V-1 permutations of the input data frame and one novel phase rotation vector called SPI (side phase of IFFT) to multiply the V permuted sequences (the original sequences and the V-1 permuted sequences), and then the frame with the lowest PAR is chosen for transmission. Simulation results show that the new method achieves better CCDF performance than the other two OFDM systems.