A Histogram Matching Technique in Sample Capture for Improving Stability of Adaptive Digital Predistorter

Abstract

The amplitude of the signal with fluctuating envelope will inevitably lead to distortion because of the nonlinear characteristics of the power amplifier (PA). These nonlinear effects can be counteracted by the adaptive digital pre-distortion (ADPD). During the updating of ADPD lookup table (LUT), it is difficult to ensure stability because of the changes of external environment. As the method of histogram matching mask, the power level, peak value and distribution of sample data is taken into account for improving stability of DPD system is presented in this paper. Experiment shows that this method can obtain more stability for effective DPD.