Performance Evaluation of LUT and Polynomial Based DPD for RF Power Amplifiers

Abstract

Wireless sensor networks (WSNs) have emerged as a key technology for distributed sensing in remote areas, offering a wide range of applications. This paper investigates the use of the digital predistortion (DPD) algorithm to enhance the linearity of Radio frequency (RF) power amplifier (PA). The technique involves applying digital baseband pre-distortion before the amplifier to mitigate nonlinear distortions, allowing the amplifier to operate closer to its peak power while reducing spectral regrowth. Three different numerical models of the RF PA were tested using a Wideband Code Division Multiple Access (WCDMA) signal for the input. Experimental validation was carried out by comparing the PA's output signal with the numerical models results. Significant improvements in efficiency and linearity were observed, attributed to the adaptive DPD algorithm, as indicated by reductions in Normalized Mean Square Error (NMSE) and Adjacent channel power ratio (ACPR) values.