Indoor Massive MIMO Deployments for Uniformly High Wireless Capacity

We consider three multi-antenna interference management schemes for high-performance wireless indoor networks: Zero Forcing (ZF), entailing neither base station (BS) coordination or inter-cell interference mitigation; Network MIMO (NeMIMO), where full BS coordination enables centralized inter-cell interference management; and Eigen-direction-aware ZF (EDA-ZF) -- proposed in this paper -- with partial coordination and distributed interference suppression. We evaluate the performance of said schemes for three sub-6 GHz deployments with varying BS densities -- sparse, intermediate, and dense -- all with fixed total number of antennas and radiated power. Extensive simulations show that: (i) indoor massive MIMO implementing the proposed EDA-ZF provides uniformly good rates for all users; (ii) indoor network densification is detrimental unless full coordination is implemented; (iii) deploying NeMIMO pays off under strong outdoor interference, especially for cell-edge users.