Abstract: According to the higher PAPR in the OFDM system, by analyzing the frequency distribution of constellation points after clipping, the code restriction technique is adopted to combat the effect of clipping the OFDM signal in the digital part of the transmitter. The code restriction technique is adopted to constrain every constellation point in the certain region, and lessen ICI or ISI through modulation. The code restriction technique and clipping are combined to achieve higher PAPR reduction and better BER, which can be seen from the simulation results of CCDF and BER based on MATLAB.

Key words: OFDM, PAPR, the code restriction technique, BER