Performance Analysis of Two???Dimensional Massive Antenna Arrays for Future Mobile Networks

In this paper, the performance of a massive multiple-antenna system under the pilot contamination effect is studied. A 2-D massive antenna array with a uniform circular array (UCA) topology at base stations (BSs) is considered. A 3-D spatial channel model with Von Mises Fisher (VMF) distribution is applied. It is shown that the interfering channels tend to fall into the null space of the desired user´s covariance matrix. The pilot contamination can be mitigated if the angle-of-arrival (AoA) pairs of the interfering users have a nonoverlapping region with the AoA of the desired user. The impact of the AoA distribution on the beam pattern is studied as well. Numerical results confirm the analysis and show that the mitigation of pilot contamination depends on the directional dispersion of the multipath AoA distribution.