Low-complexity FPGA implementation of Volterra predistorters for power amplifiers

Abstract

In this paper we present a FPGA design of a digital predistorter (DP) for power amplifiers (PAs) regarding memory effects. As model description the baseband Volterra series are utilized. A reduction of Volterra coefficients can be achieved using their symmetry properties. An advantage of our DP approach is a direct offline model identification, without need to analytically or iteratively calculate a PA model inverse. The DP implementation is very flexible and saves FPGA resources. Our simulation and measurement results show a good linearization performance applying simple Volterra model structures. DP with and without memory are compared.