A robust non-uniform indexation of a quadratically interpolated LUT predistorter for RF power amplifiers

• Main Authors: Selvadurai, Dinaagaren, Mohd Sidek, Roslina, Varahram, Pooria, Mohd Ali, Borhanuddin
• Format: Conference or Workshop Item
• Language: English
• Published: IEEE 2015
• Online Access: http://psasir.upm.edu.my/id/eprint/68890/1/A%20robust%20non-uniform%20indexation%20of%20a%20quadratically%20interpolated%20LUT%20predistorter%20for%20RF%20power%20amplifiers.pdf; http://psasir.upm.edu.my/id/eprint/68890/

A new companding function is proposed for non-uniform indexation of a quadratically interpolated LUT predistorter used in digital predistortion under wideband signals. In digital predistortion, lookup table (LUT) predistorters are the most frequently used technique in order to compensate the non-linear effects of a power amplifier. In this paper, a new companding function of a quadratically interpolated LUT predistorter is designed in order to reduce the approximation errors of quadratic interpolation which causes the intermodulation (IMD) distortion. Simulation result shows that the proposed technique provides a better rejection of intermodulation distortion compared to quadratic interpolated LUT, linear interpolated LUT and conventional non-linear interpolated LUT predistorters respectively.