Elevation domain measurement and modeling of UMa uplink channel with UE on different floors

The elevation beamforming and spatial multiplexing are promising approaches to increase throughput for user equipments (UEs) in high-rise buildings in cellular networks. However, the 3-dimensional propagation characteristics with the UEs located at different heights have been less explored. In this paper, we present field measurements on the indoor-to-outdoor (I20) uplink channel in a typical urban macro-cellular (UMa) scenario, with the emphasis on the spatial power profile in the elevation domain. The base station (BS) was installed on the top of a 5-floor building and the UE was located at 120 positions on the 1st to the 4th floors in 3 different buildings 120 to 150 m away. Using the channel sounder equipped with uniform planar antenna arrays, the elevation angle/spread of arrival (EoA/ESA) of the multipath components (MPCs) arriving at the BS were measured. Furthermore, it is found that EoA and ESA of the MPCs can be well modeled by Laplacian and Lognormal distributions, respectively, and the distribution parameters have no dependency on the UE height in this scenario. Finally, the model parameters are given based on our measurement data. This work can extend the current 2D channel models to support the design of UE direction estimation, beamforming, and sectorization in the elevation domain.