Explicit, closed-form performance analysis in fading via new bound on Gaussian Q-function

This paper aims at providing explicit, closed-form solutions to the error probability performance analysis of digital communications over fading channels. This is achieved by first deriving a family of new upper bounds on the Gaussian Q-function Q(x), which is given by a sum of products of the exponential function and c/x where c is a constant. The bounds obtained can be made arbitrarily tight as the number of summation terms increases, and thus, can be used to approximate Q(x) accurately. Their applications to the performance analysis over fading are then presented to highlight the significance of the bounds derived. Both short-term fading and combined short-term and long-term fading are considered. It is shown that the new bounds can lead to better performance than the popular exponential-type upper bounds.