A Novel Adaptive Digital Predistortion for RF Power Amplifier Linearization Based on Simplified Volterra Series

Adaptive digital predistortion (ADPD) is an effective approach to compensate for nonlinear distortion introduced by RF power amplifiers (PAs). Volterra series is applicable for predistorter design to linearize memory PAs; however, the number of its kernels to be identified increases greatly with its degree and memory length. In this paper, a simplified Volterra series (SVS) predistorter model is proposed. By only preserving partial Volterra kernels in the region near the main diagonal, the structure is simplified and computational complexity is reduced dramatically. Through MATLAB simulations using a Wiener-Hammerstein PA model and a two-carrier WCDMA wideband signal, linearization performances of SVS-based predistorters are demonstrated in terms of suppressing spectral regrowth.