A New Method for PAR Reduction of OFDM Signal Based on Chaotic Encoder

In this paper, we propose using chaotic digital filter to encode the time domain signal x_n to reduce peak-to-average power ratio (PAR) in OFDM system. The x_n may have high PAR value, which is a main drawback of OFDM system. The time domain signal becomes chaotically distributed by chaotic encoding, so the PAR value can be reduced. Simulations are done for numbers of subcarriers being 16, 32, 64, 128, 256 and 512. The simulation results show that this method can greatly reduce the PAR of OFDM signal. The chaotic encoder and decoder are easy to be implemented in hardware. In addition, the code rate is equal to the original code rate. Moreover, this method is applicable to all kinds of modulation, because chaotic encoder operates on the time domain signal.