  The coded caching scheme proposed by Maddah-Ali and Niesen considers the
delivery of files in a given content library to users through a deterministic
error-free network where a common multicast message is sent to all users at a
fixed rate, independent of the number of users. In order to apply this paradigm
to a wireless network, it is important to make sure that the common multicast
rate does not vanish as the number of users increases. This paper focuses on a
variant of coded caching successively proposed for the so-called combination
network, where the multicast message is further encoded by a Maximum Distance
Separable (MDS) code and the MDS-coded blocks are simultaneously transmitted
from different Edge Nodes (ENs) (e.g., base stations or access points). Each
user is equipped with multiple antennas and can select to decode a desired
number of EN transmissions, while either nulling of treating as noise the
others, depending on their strength. The system is reminiscent of the so-called
evolved Multimedia Broadcast Multicast Service (eMBMS), in the sense that the
fundamental underlying transmission mechanism is multipoint multicasting, where
each user can independently and individually (in a user-centric manner) decide
which EN to decode, without any explicit association of users to ENs. We study
the performance of the proposed system when users and ENs are distributed
according to homogeneous Poisson Point Processes in the plane and the
propagation is affected by Rayleigh fading and distance dependent pathloss. Our
analysis allows the system optimization with respect to the MDS coding rate.
Also, we show that the proposed system is fully scalable, in the sense that it
can support an arbitrarily large number of users, while maintaining a
non-vanishing per-user delivery rate.
