Propagation path loss models for LTE-advanced urban relaying systems

Relaying technology - a key technical enhancement in 3GPP LTE-Advanced (3rd Generation Partnership Project Long Term Evolution - Advanced) - has attracted much research interest over the last few years. However, propagation path loss models dedicated to relaying systems are yet to be properly validated. Moreover, the impact of relay antenna height on propagation channel has not yet been adequately studied. This paper presents a measurement-based study which aims to analyze the impact of relay antenna height on path loss channel models. The analysis results demonstrate that BS-RS (Base Station - Relay Station) link path loss decreases with the increase in relay antenna height. Moreover, different propagation models which could be applied for BS-RS link are verified. The analyses show that these models are not completely adequate for relaying deployment. Finally, a new propagation model for relaying deployment which takes into account the impact of relay antenna height is proposed.