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arXiv · 1503.00656

Space-Constrained Massive MIMO: Hitting the Wall of Favorable Propagation

Christos Masouros·Michail Matthaiou
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Abstract

The recent development of the massive multiple-input multiple-output (MIMO) paradigm, has been extensively based on the pursuit of favorable propagation: in the asymptotic limit, the channel vectors become nearly orthogonal and inter-user interference tends to zero [1]. In this context, previous studies have considered fixed inter-antenna distance, which implies an increasing array aperture as the number of elements increases. Here, we focus on a practical, space-constrained topology, where an increase in the number of antenna elements in a fixed total space imposes an inversely proportional decrease in the inter-antenna distance. Our analysis shows that, contrary to existing studies, inter-user interference does not vanish in the massive MIMO regime, thereby creating a saturation effect on the achievable rate.

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Christos Masouros, Michail Matthaiou. 2015-03-02. Space-Constrained Massive MIMO: Hitting the Wall of Favorable Propagation. https://arxiv.org/abs/1503.00656

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