Predistorter design for a memory-less nonlinear high power amplifier using the pth-order inverse method for OFDM systems

Abstract

We present a digital predistorter design scheme to compensate for the memory-less high power amplifier (HPA) nonlinearity to reduce the effect of high PAPR and the spectral re-growth of OFDM signals using the pth-order inverse method. The memory-less HPA is modeled with a polynomial and then the pth-order inverse method is applied to the polynomial model instead of solving for the exact inverse polynomial. We compensate for the amplitude and the phase nonlinearities separately, which makes the compensation process simpler than when compensated using the complex computation. The proposed predistorter can adapt to the time-varying characteristics of the memory-less HPA.