Analytical Framework for Full Dimensional Massive MIMO with Ray-Based Channels

Research output: Contribution to journalArticle

Abstract

The performance of baseband beamforming in multi-user multiple-input multiple-output (MU-MIMO) systems has been extensively studied for simplified statistical channel models where no angular parameters are taken into account. In contrast, there is little performance analysis with ray-based models, which are more physically motivated, feature prominently in standardization and have been experimentally validated. Thus, unlike previous studies, we present a mathematical framework to analyze the performance of zero-forcing (ZF) and minimum-mean-squared-error (MMSE) combining. Using a central result for averaging in the angular domain, we derive tight approximations for the uplink signal-to-noise ratio and signal-to-interference-and-noise ratio (SINR) for ZF and MMSE processing, respectively, and the resulting spectral efficiencies. The remarkably simple expressions offer the following insights into the effects of the propagation environment. We demonstrate an increase in performance when moving from vertical uniform rectangular array (URA) to horizontal URA to uniform linear array (ULA) antenna configurations. There is also a corresponding increase in the robustness of the performance to propagation scenarios. We demonstrate that under specific conditions increasing the angular spread can decrease the SINR for a ULA - an unexpected behavior which we link to the effects of end-fire radiation. Furthermore, our results allow us to investigate the impact of different array configurations and system parameters on the rate of convergence to favorable propagation conditions. Finally, we evaluate the spatial correlation properties intrinsically present in ray-based models, and compare them to the commonly used simple exponential model which yields equal, fixed correlation characteristics for each user.

Details

Authors
  • Chelsea L Miller
  • Peter J Smith
  • Pawel A Dmochowski
  • Harsh Tataria
  • Michail Matthaiou
Organisations
External organisations
  • Victoria University of Wellington
  • Queen's University Belfast
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Communication Systems
  • Telecommunications
  • Signal Processing

Keywords

  • Ergodic spectral efficiency, favorable propagation, linear processing, MU-MIMO, ray-based channel models
Original languageEnglish
Pages (from-to)1181 - 1195
Number of pages14
JournalIEEE Journal on Selected Topics in Signal Processing
Volume13
Publication statusPublished - 2019 Aug 27
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

Special Issue on Array Signal Processing for Angular Models in Massive MIMO Communications