Closed-loop sign algorithms for low-complexity digital predistortion

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

2 Citations (Scopus)
12 Downloads (Pure)


In this paper, we study digital predistortion (DPD) based linearization with specific focus on millimeter wave (mmW) active antenna arrays. Due to the very large channel bandwidths and beam-dependence of nonlinear distortion in such systems, we propose a closed-loop DPD learning architecture, look-up table (LUT) based memory DPD models, and low-complexity sign-based estimation algorithms, such that even continuous DPD learning could be technically feasible. To this end, three different learning algorithms - sign, signed regressor, and sign-sign - are formulated for the LUT-based DPD models, such that the potential rank deficiencies, experienced in earlier methods, are avoided. Then, extensive RF measurements utilizing a state-of-the-art mmW active antenna array system at 28 GHz are carried out and reported to validate the methods. Additionally, the processing and learning complexities of the considered methods are analyzed, which together with the measured linearization performance figures allow to assess the complexity-performance tradeoffs. Overall, the results show that efficient mmW array linearization can be obtained through the proposed methods.

Original languageEnglish
Title of host publicationIMS 2020 - 2020 IEEE/MTT-S International Microwave Symposium
Number of pages4
ISBN (Electronic)9781728168159
Publication statusPublished - Aug 2020
Publication typeA4 Article in a conference publication
EventIEEE/MTT-S International Microwave Symposium - Virtual, Los Angeles, United States
Duration: 4 Aug 20206 Aug 2020

Publication series

NameIEEE MTT-S International Microwave Symposium Digest
ISSN (Print)0149-645X


ConferenceIEEE/MTT-S International Microwave Symposium
Country/TerritoryUnited States
CityVirtual, Los Angeles


  • ACLR
  • Array transmitters
  • Digital predistortion
  • Hadamard
  • Lookup table
  • MmW frequencies
  • Nonlinear distortion
  • Sign algorithm
  • Signed regressor

Publication forum classification

  • Publication forum level 1

ASJC Scopus subject areas

  • Radiation
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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