Power Adaptive Digital Predistortion for Wideband RF Power Amplifiers With Dynamic Power Transmission

Abstract

He is currently with the RF and Microwave Research Group, UCD. His research interests include spectrum sensing for cognitive radio, digital predistortion for RF power amplifiers, and field-programmable gate-array (FPGA) hardware implementations.

An Adaptive Cascaded ILA- and DLA-Based Digital Predistorter for Linearizing an RF Power Amplifier

“…Thus, it is not applicable in a real-time application. Therefore, in [8], the root-finding process is substituted by a LILUT algorithm, which estimates the amplitude |x(n)| and phase α of x(n) based on (6). Firstly, the dynamic range of |x(n)| is estimated according to the characteristics of the PA [26].…”

Power adaptive decomposed vector rotation based digital predistortion for RF power amplifiers in dynamic power transmission

“…However, since the PA nonlinear change is simply modeled as a point-wise linear interaction between the model terms and s(n), its model capacity in the scenario of multiple power levels is limited. To overcome this, [2] proposed to weight the linear and nonlinear terms separately, meaning that:…”

“…This method is able to improve the performance in the scenario of two different power levels, but has limited performance when the PA is operated in a large dynamic power range. A power adaptive DPD approach in [2] was proposed to further improve the modeling accuracy in the cases of multiple power levels. The high model accuracy however comes with the price of complex control logic, which increases implementation complexity.…”

A Digital RF Transmitter With Background Nonlinearity Correction

“…Prior work on background calibration of analog transmitters relies on FPGA-based or Matlabbased correction with off-the-shelf components [11], [12]. Also, the system in [12] takes half a second to adapt to new conditions, and corrects for only static nonlinearity.…”