  We consider the content delivery problem in a fading multi-input
single-output channel with cache-aided users. We are interested in the
scalability of the equivalent content delivery rate when the number of users,
$K$, is large. Analytical results show that, using coded caching and wireless
multicasting, without channel state information at the transmitter (CSIT),
linear scaling of the content delivery rate with respect to $K$ can be achieved
in some different ways. First, if the multicast transmission spans over $L$
independent sub-channels, e.g., in quasi-static fading if $L = 1$, and in block
fading or multi-carrier systems if $L>1$, linear scaling can be obtained when
the product of the number of transmit antennas and the number of sub-channels
scales logarithmically with $K$. Second, even with a fixed number of antennas,
we can achieve the linear scaling with a threshold-based user selection
requiring only one-bit feedbacks from the users. When CSIT is available, we
propose a mixed strategy that combines spatial multiplexing and multicasting.
Numerical results show that, by optimizing the power split between spatial
multiplexing and multicasting, we can achieve a significant gain of the content
delivery rate with moderate cache size.
