A Tractable Product Channel Model for Line-of-Sight Scenarios

TL;DR

This paper introduces a new, mathematically tractable LOS fading model based on the product of two independent $oldsymbol{ ext{kappa-}oldsymbol{ extmu}}$ shadowed variables, simplifying analysis of LOS channels in wireless communications.

Contribution

It proposes a novel LOS fading model with closed-form expressions, enabling easier analysis of LOS and mixed LOS/non-LOS channels in wireless systems.

Findings

Model provides accurate fit to field measurements.

Offers closed-form expressions for key statistical functions.

Enhances analysis of wireless powered and device-to-device communications.

Abstract

We present a general and tractable fading model for line-of-sight (LOS) scenarios, which is based on the product of two independent and non-identically distributed $\kappa$-$\mu$ shadowed random variables. Simple closed-form expressions for the probability density function, cumulative distribution function and moment-generating function are derived, which are as tractable as the corresponding expressions derived from a product of Nakagami-$m$ random variables. This model simplifies the challenging characterization of LOS product channels, as well as combinations of LOS channels with non-LOS ones. We leverage these results to analyze performance measures of interest in the contexts of wireless powered and backscatter communications, where both forward and reverse links are inherently of LOS nature, as well as in device-to-device communications subject to composite fading. In these contexts, the model shows a higher flexibility when fitting field measurements with respect to conventional approaches based on product distributions with deterministic LOS, together with a more complete physical interpretation of the underlying propagation characteristics.