  Fluid antenna represents a concept where a mechanically flexible antenna can
switch its location freely within a given space. Recently, it has been reported
that even with a tiny space, a single-antenna fluid antenna system (FAS) can
outperform an L-antenna maximum ratio combining (MRC) system in terms of outage
probability if the number of locations (or ports) the fluid antenna can be
switched to, is large enough. This letter aims to study if extraordinary
capacity can also be achieved by FAS with a small space. We do this by deriving
the ergodic capacity, and a capacity lower bound. This letter also derives the
level crossing rate (LCR) and average fade duration (AFD) for the FAS.
