MGF Approach to the Analysis of Generalized Two-Ray Fading Models

TL;DR

This paper introduces a closed-form MGF for GTR fading channels, simplifying the analysis of key performance metrics and highlighting the impact of phase difference distributions on average SNR.

Contribution

It derives a novel closed-form MGF for GTR fading models, enabling easier computation of performance metrics and considering more general phase difference distributions.

Findings

Closed-form MGF simplifies performance analysis.

Phase difference distribution affects average SNR.

Expressions for fading, error rate, and capacity derived.

Abstract

We analyze a class of Generalized Two-Ray (GTR) fading channels that consist of two line of sight (LOS) components with random phase plus a diffuse component. We derive a closed form expression for the moment generating function (MGF) of the signal-to-noise ratio (SNR) for this model, which greatly simplifies its analysis. This expression arises from the observation that the GTR fading model can be expressed in terms of a conditional underlying Rician distribution. We illustrate the approach to derive simple expressions for statistics and performance metrics of interest such as the amount of fading, the level crossing rate, the symbol error rate, and the ergodic capacity in GTR fading channels. We also show that the effect of considering a more general distribution for the phase difference between the LOS components has an impact on the average SNR.