Power Inversion of the Massive MIMO Channel

TL;DR

This paper introduces a model for massive MIMO channels that bounds channel hardening and enables power inversion based on large scale fading, improving radio design and downlink channel reliability.

Contribution

It presents a new effective channel model for massive MIMO that bounds channel hardening and facilitates power inversion based on large scale fading.

Findings

Bounds on channel hardening in massive MIMO

Effective channel model for maximum diversity channels

Power inversion relying solely on large scale fading

Abstract

Channel hardening characterises the diminishing influence of small scale fading on large scale antenna systems. The effective massive MIMO time domain channel is introduced and applied to a maximum diversity channel with rectangular power delay profile. This model bounds channel hardening and allows a proper interpretation from a radio design perspective. The reduced variability of the effective channel enables power inversion to obtain a downlink channel that only depends on the large scale fading properties.