Uplink Interference Analysis with RF Switching for Lens-Based Millimeter-Wave Systems

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


In this paper, we take a fundamental look at the interference characteristics of a lens-based millimeter-wave (mmWave) multiuser multiple-input multiple-output system (MU-MIMO) system. We consider a hybrid architecture, implemented via a bank of radio-frequency (RF) switches which perform beam selection followed by low-complexity uplink maximum-ratio combining (MRC) at baseband. Considering a Rotman lens antenna array in line- of-sight (LoS) propagation, we derive tight analytical approximations to the average (expected) interference power of an arbitrary terminal, with and without the presence of RF switching. The analytical expressions show that without RF switching, the Rotman lens losses its benefits and collapses to a conventional uniform linear array. Our numerical results demonstrate that the expected interference power to a given terminal decreases significantly with RF switching, due to beam selection separating the uplink direction-of-arrivals (DoAs), in contrast to the case without RF switching, which relaxes the beam selection constraint and thus allows very similar DoAs. Overall, the results in this paper emphasize the necessity of RF switching in order to obtain superior performance with lens arrays, over conventional phased arrays.


  • Harsh Tataria
  • Michail Matthaiou
  • Peter J Smith
  • George C Alexandropoulos
  • Vincent F Fusco
External organisations
  • Queen's University Belfast
  • Victoria University of Wellington
  • Huawei Technologies France
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Communication Systems


  • Interference, RF switching, LOS propagation, Multibeam arrays, Lens systems
Original languageEnglish
Title of host publicationIEEE International Conference on Communications (ICC) 2018
PublisherIEEE--Institute of Electrical and Electronics Engineers Inc.
Number of pages7
ISBN (Electronic)978-1-5386-3180-5
ISBN (Print)978-1-5386-3181-2
Publication statusPublished - 2018 May 23
Publication categoryResearch
EventIEEE International Conference on Communications (ICC) 2018 - Sheraton Kansas City Hotel, Kansas City, United States
Duration: 2018 May 232018 May 27


ConferenceIEEE International Conference on Communications (ICC) 2018
Abbreviated titleICC
CountryUnited States
CityKansas City
Internet address