  We investigate the feasibility of using Massive MIMO to support URLLC in both
coherence interval based and 3GPP compliant pilot settings. We consider
grant-free uplink transmission with MMSE receiver and adopt 3GPP channel
models. In the coherence interval based pilot setting, by extensive system
level simulations, we find that using a Massive MIMO base station with 128
antennas and MMSE receiver, URLLC requirements can be achieved in Urban Macro
(UMa) Non-Line of Sight (NLoS) with orthogonal pilots and Neyman-Pearson
detector. However, in the 3GPP compliant pilot setting, even by using the
covariance matrix of Physical Resource Block (PRB) subcarriers for active UE
detection and channel estimation as well as open-loop power control, we find
that URLLC requirements are still challenging to achieve due to the
insufficient pilot length and pilot symbol location regulations in a PRB.
