Comments on “On Favorable Propagation in Massive MIMO Systems and Different Antenna Configurations”

Abstract

It is shown that the condition of Theorem 1 in (X. Wu, N. C. Beaulieu, D. Liu, “On favorable propagation in massive MIMO systems and different antenna configurations,” IEEE Access, vol. 5, pp. 5578-5593, May 2017) 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.

Keywords

• Massive MIMO
• favorable propagation
• asymptotic orthogonality