Comments on "On Favorable Propagation in Massive MIMO Systems and Different Antenna Configurations" [1]

TL;DR

This paper critically examines the theoretical results in a prior work on massive MIMO systems, showing that key theorems do not hold in practice without additional assumptions or modifications.

Contribution

It identifies inaccuracies in existing theorems about favorable propagation in massive MIMO and proposes necessary conditions for their validity.

Findings

Theorem 1's condition does not hold in practice.

Theorem 2 is incorrect under the original assumptions.

Additional assumptions are required for the theorems to be valid.

Abstract

It is shown that the condition of Theorem 1 in [1] never holds in practice and that Theorem 2 is incorrect under the stated condition. Extra assumptions or/and modifications are needed to make the conclusions of Theorem 1 and 2 above valid, which are provided below.