Nonlinear noise mitigation by decision-aided reconstruction in OFDM system

Orthogonal frequency division multiplexing (OFDM) is a multi-carrier digital modulation technique that has been under extensive study and research in recent years, in terms of considering its various advantage in combating the severe effects of the frequency selective fading. However, the OFDM system suffers from the strong sensitivity to the nonlinear distortion, introduced by the transmitting high power amplifier (HPA), since the OFDM system has the high peak-to-average power ratio (PAPR). Clipping is the simple but infective method to low the high PAPR; however, it causes nonlinear distortion too. So in this paper, we propose a new approach to compensate the nonlinearity caused by clipping and HPA. Its performance is verified through computer simulations. Specifically, the enhanced performance in terms of the bit error rate (BER) is documented for both the traveling wave tube amplifier (TWTA) and the solid state power amplifier (SSPA).