  This letter investigates the performance of content caching in a
heterogeneous cellular network (HetNet) consisting of fluid antenna system
(FAS)-equipped mobile users (MUs) and millimeter-wave (mm-wave) single-antenna
small base stations (SBSs), distributed according to the independent
homogeneous Poisson point processes (HPPP). In particular, it is assumed that
the most popular contents are cached in the SBSs to serve the FAS-equipped MUs
requests. To assess the system performance, we derive compact expressions for
the successful content delivery probability (SCDP) and the content delivery
delay (CDD) using the Gauss-Laguerre quadrature technique. Our numerical
results show that the performance of cache-enabled mm-wave HetNets can be
greatly improved, when the FAS is utilized at the MUs instead of traditional
fixed-antenna system deployment.
