  In this correspondence, we analyze the ergodic capacity of a large uplink
multi-user multiple-input multiple-output (MU-MIMO) system over generalized-$K$
fading channels. In the considered scenario, multiple users transmit their
information to a base station equipped with a very large number of antennas.
Since the effect of fast fading asymptotically disappears in massive MIMO
systems, large-scale fading becomes the most dominant factor for the ergodic
capacity of massive MIMO systems. Regarding this fact, in our work we
concentrate our attention on the effects of large-scale fading for massive MIMO
systems. Specifically, some interesting and novel lower bounds of the ergodic
capacity have been derived with both perfect channel state information (CSI)
and imperfect CSI. Simulation results assess the accuracy of these analytical
expressions.
