Spectral Efficiency Analysis in Dense Massive MIMO Networks

This work considers the uplink of a Massive MIMO network wherein the base stations (BSs) are randomly deployed according to a homogenous Poisson point process of intensity λ. Each BS is equipped with M antennas and serves K user equipments. A rigorous stochastic geometry framework with a multi-slope path loss model and pilot-based channel estimation is used to analyze the impact of A on channel estimation accuracy and spectral efficiency. Both maximum ratio and zero-forcing combiners are considered. Interesting analytical insights are provided into the interplay of network parameters such as λ, antenna- UE ratio M / K, and pilot reuse factor. The relative strength of pilot contamination and (inter- and intra-cell) interference is analytically and numerically evaluated, as a function of λ. It turns out that pilot contamination becomes relevant only for impractical values of M / K ≥ 100.