A tractable model for per user rate in multiuser millimeter wave cellular networks

Large antenna arrays will be deployed at base stations (BSs) and user equipments (UEs) in future millimeter wave (mmWave) cellular networks. Although highly directional beamforming is a key enabling technology, the optimal way to use these large arrays is still unclear. With this broad goal in mind, we compare the coverage and rate performance of fully-connected hybrid beamforming enabled multiuser (MU) MIMO with single user beamforming (SU-BF). We show that MU-MIMO has the potential to give higher per user rates but at the cost of higher power consumption and reduced signal to interference plus noise ratio (SINR). However, if only the average power per unit area is preserved, a denser SU-BF network usually outperforms MU-MIMO in terms of cell edge rates. A stochastic geometry based model that captures these trends for a large number of antennas at the BSs and UEs is proposed.