A cache-aided erasure broadcast channel is studied.
The receivers are divided into two sets: the weak and strong
receivers, where the receivers in the same set all have the same
erasure probability. The weak receivers, in order to compensate
for the high erasure probability, are equipped with cache mem-
ories of equal size, while the receivers in the strong set have
no caches. Data can be pre-delivered to weak receivers’ caches
over the off-peak traffic period before the receivers reveal their
demands. A joint caching and channel coding scheme is proposed
such that all the receivers, even the receivers without any cache
memories, benefit from the presence of caches across the network.
The trade-off between the cache size and the achievable rate is
studied, and it is shown that the proposed scheme significantly
improves the achievable trade-off upon the state-of-the-art.