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

作者：Masouros Christos^*; Matthaiou Michail

来源：IEEE Communications Letters, 2015, 19(5): 771-774.

DOI：10.1109/LCOMM.2015.2409832

• Antenna arrays
• favorable propagation
• massive MIMO

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.

• 出版日期2015-5