Alternative Formulations for the Fluctuating Two-Ray Fading Model

We present two alternative frameworks for the statistical characterization and performance evaluation of the fluctuating two-ray (FTR) fading model which simplify previous approaches. The new formulations are based on the fact that the FTR fading distribution can be described, for arbitrary
$m$
, as an underlying Rician Shadowed (RS) distribution with continuously varying parameter
$K_{r}$
(ratio of specular to diffuse power components), while for the special case of
$m$
being an integer, it is demonstrated that the FTR fading model can be described in terms of a finite number of underlying squared Nakagami-
$m$
distributions. It is shown that any performance metric that is computed by averaging over the probability density function (PDF) of the FTR fading model can be expressed in terms of a finite-range integral over the corresponding performance metric for the simpler RS (for arbitrary
$m$
) or Nakagami-
$m$
(for integer
$m$
) fading models, for which many results are available in closed-form. New expressions for some Laplace-domain statistics of interest are also obtained; these are used to analyze the outage probability of FTR fading under co-channel interference, as well as to obtain closed-form expressions for the main statistics of a composite wireless channel model encompassing FTR fading and shadowing.