An improvement iterative approach for wideband digital predistortion using under-sampling

Abstract

The performance of the traditional approach of wideband digital pre-distortion (DPD) of radio frequency (RF) power amplifier (PA) is subject to the analog to digital converter (ADC) sampling rate of transmitter. In this paper, an improvement DPD iterative approach is proposed. Firstly, DPD input signal and PA output signal are under-sampled by Zhu's generalized sampling theorem (ZGST). Secondly, an optimized iterative model is employed to obtain DPD model. The parameters of it can be extracted by DPD input signal and PA output signal. This improvement DPD iterative approach not only reduces hardware requirement of ADC sampling rate but also gives almost same linear performance with that by full sampling rate. The performance is validated by measurement result.