Uniform Linear Arrays with Optimized Inter-Element Spacing for LOS Massive MIMO

Amirashkan Farsaei (Corresponding author), Navid Amani, Rob Maaskant, Ulf Gustavsson, Alex Alvarado, Frans M.J. Willems

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In this letter, a uniform linear array (ULA) is proposed for line-of-sight massive multiple-input-multiple-output (MIMO). It is assumed that the number of antennas is fixed. For a given ULA with an arbitrary inter-element spacing, the probability that the correlation among the channel vectors of two users being above a threshold value is derived. The inter-element spacing of the proposed ULA is the one for which the aforementioned probability is minimized. To show the effectiveness of the proposed ULA, simulation results for two scenarios are given for a 64-Antenna ULA that serves 6 single-Antenna users. By using the proposed ULA instead of conventional half-wavelength ULA, 5th percentile sum-rate for zero-forcing precoder is improved by 9.90 bits/channel use in first scenario without dropping, and by 1.43 bits/channel use in second scenario with dropping 1 user.

Original languageEnglish
Article number9222215
Pages (from-to)613-616
Number of pages4
JournalIEEE Communications Letters
Issue number2
Publication statusPublished - Feb 2021

Bibliographical note

Funding Information:
Manuscript received September 18, 2020; accepted October 7, 2020. Date of publication October 13, 2020; date of current version February 11, 2021. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 721732. The associate editor coordinating the review of this letter and approving it for publication was M. C. Aguayo-Torres. (Corresponding author: Amirashkan Farsaei.) Amirashkan Farsaei, Alex Alvarado, and Frans M. J. Willems are with the Department of Electrical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands (e-mail: a.farsaee@tue.nl; a.alvarado@tue.nl; f.m.j.willems@tue.nl).

Publisher Copyright:
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  • Line-of-sight
  • massive MIMO
  • uniform linear array
  • zero-forcing


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