Compensation of nonlinear distortion using a predistorter based on the fixed point approach in OFDM systems

We present a new design scheme of a predistorter to compensate for distortion introduced by nonlinear high power amplifiers (HPAs) employed in orthogonal frequency division multiplexing (OFDM) systems. Since the signal amplitude of the OFDM system is Rayleigh-distributed, the performance of the OFDM system is significantly degraded by the nonlinearity of the HPA in the OFDM transmitter. In order to mitigate this distortion, we develop a new data predistorter, which rests upon the fixed point approach associated with the contraction mapping theorem. With utilization of the proposed predistorter, we can significantly improve the performance of the OFDM system compared to that of the system without the predistorter in terms of the bit error rate. Furthermore, since the proposed predistorter utilizes an iterative method, its implementation is relatively simple