  The secrecy outage performance of wireless communication systems operating
over spatially correlated composite fading channels is analyzed in this paper.
We adopt a multiplicative composite channel model for both the legitimate
communication link and the link between the eavesdropper and the legitimate
transmitter, consisting of Nakagami-$m$ distributed small-scale fading and
shadowing (large-scale fading) modeled by the Gamma distribution. We consider
the realistic case where small-scale fading between the links is independent,
but shadowing is arbitrarily correlated, and present novel analytical
expressions for the probability that the secrecy capacity falls below a target
secrecy rate. The presented numerically evaluated results, verified by
equivalent computer simulations, offer useful insights on the impact of
shadowing correlation and composite fading parameters on the system's secrecy
outage performance.
