1-Bit Observation for Direct-Learning-Based Digital Predistortion of RF Power Amplifiers

DOI number:10.1109/TMTT.2016.2642945

Journal:IEEE Transactions on Microwave Theory and Techniques

Funded by:NSFC 61471333

Key Words:Analog-to-digital converter (ADC), digital predistortion (DPD), error signal, linearization, low resolution, power amplifier (PA), wideband

Abstract:In this paper, we propose a low-cost data-acquisition approach for model extraction of digital predistortion (DPD) of RF power amplifiers. The proposed approach utilizes only 1-bit-resolution analog-to-digital converters (ADCs) in the observation path to digitize the error signal between the input and output signals. The DPD coefficients are then estimated based on the direct learning architecture using the measured signs of the error signal. The proposed solution is proved feasible in theory, and the experimental results show that the proposed algorithm achieves the performance equivalent to that using the conventional method. Replacing high-resolution ADCs with 1-bit comparators in the feedback path can dramatically reduce the power consumption and cost of the DPD system. The 1-bit solution also makes DPD become practically implementable in future broadband systems since it is relatively straightforward to achieve an ultrahigh sampling speed in data conversion using only simple comparators.

First Author:Haoyu Wang (王昊禹)

Co-author:Gang Li,Chongbin Zhou,Wei Tao,Anding Zhu

Indexed by:Journal paper

Correspondence Author:Falin Liu

Document Code:10.1109/TMTT.2016.2642945

Discipline:Engineering

Document Type:J

Volume:65

Issue:7

Page Number:2465 - 2475

Translation or Not:no

Date of Publication:2017-07-01