  A two-tier heterogeneous cellular network (HCN) with intra-tier and
inter-tier dependence is studied. The macro cell deployment follows a Poisson
point process (PPP) and two different clustered point processes are used to
model the cache-enabled small cells. Under this model, we derive approximate
expressions in terms of finite integrals for the average delivery rate
considering inter-tier and intra-tier dependence. On top of the fact that cache
size drastically improves the performance of small cells in terms of average
delivery rate, we show that rate splitting of limited-backhaul induces
non-linear performance variations, and therefore has to be adjusted for rate
fairness among users of different tiers.
