  Factory automation is one of the most challenging use cases for 5G-and-beyond
mobile networks due to strict latency, availability and reliability
constraints. In this work, an indoor factory scenario is considered, and
distributed multiple-input multiple-output (MIMO) schemes are investigated in
order to enable reliable communication to the actuators (ACs) active in the
factory. Different levels of coordination among the access points serving the
ACs and several beamforming schemes are considered and analyzed. To enforce
system reliability, a max-min power allocation (MPA) algorithm is proposed,
aimed at improving the signal to interference plus noise ratio (SINR) of the
ACs with the worst channel conditions. Extensive system simulations are
performed in a realistic scenario, which includes a new path-loss model based
on recent measurements in factory scenarios, and, also, the presence of
non-Gaussian impulsive noise. Numerical results show that distributed MIMO
schemes with zero-forcing (ZF) beamforming and MPA have the potential of
providing SINR gains in the order of tens of dB with respect to a centralized
MIMO deployment, as well as that the impulsive noise can strongly degrade the
system performance and thus requires specific detection and mitigation
techniques.
