Does Massive MIMO Fail in Ricean Channels?

TL;DR

This paper investigates the robustness of massive MIMO in Ricean channels, identifying potential failure scenarios and demonstrating that such cases are unlikely and manageable with standard scheduling, supporting its reliability in 5G networks.

Contribution

It characterizes scenarios where massive MIMO may fail in Ricean channels and shows these are unlikely and can be mitigated with standard scheduling techniques.

Findings

Harmful scenarios in Ricean fading are unlikely.

Massive MIMO effectively combats interuser interference.

Standard scheduling can compensate for potential failures.

Abstract

Massive multiple-input multiple-output (MIMO) is now making its way to the standardization exercise of future 5G networks. Yet, there are still fundamental questions pertaining to the robustness of massive MIMO against physically detrimental propagation conditions. On these grounds, we identify scenarios under which massive MIMO can potentially fail in Ricean channels, and characterize them physically, as well as, mathematically. Our analysis extends and generalizes a stream of recent papers on this topic and articulates emphatically that such harmful scenarios in Ricean fading conditions are unlikely and can be compensated using any standard scheduling scheme. This implies that massive MIMO is intrinsically effective at combating interuser interference and, if needed, can avail of the base-station scheduler for further robustness.