Reducing PAPR based on constellation mapping & fast algorithm

In this paper, we propose a new method of reducing peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing system (OFDM) based on constellation mapping. In the transmitter, the samples that exceed the maximum allowable range through IFFT are clipped by software. In the receiver, according to the characteristic of different constellation distribution which different modulation systems possess, clipped samples are restored. So, the distortion of signal is diminished and code error rate of system is decreased. According to the characteristic that total energy of OFDM symbol is constant, the fast algorithm that clipped samples are recovered is brought forward. Both theoretical analysis and simulation results show that the novel method can effectively reduce PAPR in the OFDM system, and code error performance of the system is very good. At the same time, its recovery algorithm is simple.