  In this paper, we study the effect of the absence of channel knowledge for
multiple-input-multiple-output (MIMO) networks. Specifically, we assume perfect
channel state information at the receivers, no channel state information at the
transmitter(s), and independent identically distributed (i.i.d.) Rayleigh
fading across antennas, users and time slots. We provide the characterization
of the degrees of freedom (DoF) region for a 2-user MIMO broadcast channel. We
then provide a DoF region outer bound for a 2-user MIMO interference channel.
This bound is shown to be tight for all possible combinations of the number of
antennas at each node except for one case. As a byproduct of this analysis we
point out the potential of interference alignment in the 2-user MIMO
interference channel with no CSIT.
