Adaptable look-up tables for linearizing high power amplifiers

Abstract

This paper presents a technique of adaptive digital predistortion (DPD) with a memory effect for linearization a high power amplifier (HPA). The proposed predistortion linearizer is based on Look-Up tables (LUTs) with linear interpolation and adaptive segmentation. Simulation results with a lab signal of 40W dual-band HPA with memory effect show that the proposed technique achieves a better performance compared with a common LUT-based linear interpolation in the same chip complexity. We also propose an online segmentation method, leading to a quasi-uniform noise distribution between LUTs. Additionally, an online method of LUTs memory adaptation is presented to save chip memory resources.