3D channel model in 3GPP

Multi-antenna techniques capable of exploiting the elevation dimension are anticipated to be an important air-interface enhancement targeted to handle the expected growth in mobile traffic. In order to enable the development and evaluation of such multi-antenna techniques, the 3rd Generation Partnership Project (3GPP) has recently developed a three-dimensional (3D) channel model. The existing two-dimensional (2D) channel models do not capture the elevation channel characteristics, making them insufficient for such studies. This article describes the main components of the newly developed 3D channel model and the motivations behind introducing them. One key factor is the ability to model channels for users located on different floors of a building (at different heights). This is achieved by capturing a user height dependency in modelling some channel characteristics including pathloss, lineof- sight (LOS) probability, etc. In general, this 3D channel model follows the framework of WINNERII/WINNER+ while also extending the applicability and the accuracy of the model by introducing some height dependent and distance dependent elevation related parameters.