  This paper focuses on the analysis of average Gaussian error probabilities in
certain fading channels, i.e. we are interested in E[Q((p {\gamma})^(1/2))]
where Q(.) is the Gaussian Q-function, p is a positive real number and {\gamma}
is a nonnegative random variable. We present a unified analysis of the average
Gaussian error probability, derive a compact expression in terms of the
Lauricella FD^(n) function that is applicable to a broad class of fading
channels, and discuss the relation of this expression and expressions of this
type recently appeared in literature. As an intermediate step in our
derivations, we also obtain a compact expression for the outage probability of
the same class of fading channels. Finally, we show how this unified analysis
allows us to obtain novel performance analytical results.
