2D Piecewise Digital Predistortion for Dual-Band Power Amplifiers Based on Self-organizing Map

摘要

This paper presents a new piecewise two-dimensional (2D) digital predistortion (DPD) method for dual-band power amplifiers (PAs). A self-organizing map network is used to divide dual-band signals into different regions. Then, a principal component analysis algorithm is used to reduce the number of predistortion coefficients in each region. The proposed method is stable in finding the optimum region ranges and can achieve a good balance between the system complexity and model accuracy. To validate proposed method, a dual-band WCDMA signal and a dual-band OFDM signal are employed. The device under test is a GaN PA with a peak output power of 6 W. The adjacent channel power ratio and normalized mean square error measurement results for both cases demonstrate that the new piecewise DPD method can obtain better linearization performance with fewer coefficients.