Digital predistorter based on Volterra series for nonlinear power amplifier applied to OFDM systems using adaptive algorithms

摘要

In this paper, different numerical methods to calculate the optimum coefficients in the Volterra Series are introduced to analyze the performance of a Digital Predistorter (DPD) for Power Amplifier (PA) with memory. The adaptive algorithms used are Least Mean Square (LMS), Normalized LMS (NLMS), Variable Step Size (VSS), and the VSS modified. The parameters in the Volterra Model are typically calculated based on the mean square error criteria, then in this paper we compare alternatives to reduce the complexity, number of operations, and the time in the linearization of PA through DPD measured with the OFDM signal. The simulation results show that the VSS algorithm is faster and effective to calculate the parameters in the Volterra model.