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 Kr (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.