Adaptive Compensation of High Frequency Memory Effects of a Realistic Amplifier in an OFDM System

In addition to the power nonlinearity, the high frequency (HF) memory effects of the power amplifier (PA) have a distorting influence even in the linear zone. The objective of this paper is to present a simple way to compensate for these memory effects in an orthogonal frequency division multiplex (OFDM) system. In order to represent the PA with HF memory effects in a realistic way, we use a circuit-level description by carrying out mixed digital signal processing and radio frequency (RF) circuit cosimulation. Our solution is based on the Wiener model of the PA and takes benefit of the cyclic prefix. In addition, the new compensation method takes into account the variation of the HF memory characteristics with the power. We illustrate the performance of our method and the accuracy of the Wiener model by means of digital/RF cosimulation