Efficiency analysis of Massive MIMO systems for 5G cellular networks under perfect CSI

The problem of finding theoretical sum-rate and spectral efficiency expressions for each mobile user that matches closely to realistic 5G models reduces to the application of these theoretical analysis to practical 3GPP spatial model with both the Line-Of-Sight (LOS) and Non-LOS (NLOS) propagation paths. To this end, we propose a solution to this problem by applying an uplink theoretical analysis of a massive MIMO system, with multiple cells, to the 3GPP model. In this paper, it is assumed that a BS has perfect knowledge of the channel estimates and two practical linear receivers namely the Maximum Ratio Combining (MRC) and Zero-Forcing (ZF) are considered. The Signal and Noise Interference Ratio (SINR) analysis for our proposed massive MIMO system is described and closed-form expressions are derived for the sum-rate, spectral and energy efficiencies for each mobile user with random displacement in the multi-cell network. Our analysis takes into account the effect of inter-cell interference or commonly known as pilot contamination. It is shown through simulations that when the BS antennas increase both the sum-rates and efficiencies significantly increase for the realistic 3GPP spatial channel model as compared to the analytical uncorrelated Rayleigh channel. It is observed that the spectral efficiency of mobile users for the 3GPP model is 60 bps/Hz higher than the Rayleigh counterpart when a ZF receiver is implemented at the BS with 300 antennas.