  Providing consistently high wireless capacity is becoming increasingly
important to support the applications required by future digital enterprises.
In this paper, we propose Eigen-direction-aware ZF (EDA-ZF) with partial
coordination among base stations (BSs) and distributed interference suppression
as a practical approach to achieve this objective. We compare our solution with
Zero Forcing (ZF), entailing neither BS coordination or inter-cell interference
mitigation, and Network MIMO (NeMIMO), where full BS coordination enables
centralized inter-cell interference management. We also 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.
