Effect of UE Height on 3D Angular Spread of Correlated MIMO Channel

In the forthcoming fifth generation (5G) architecture, full dimension MIMO (FD-MIMO) for enabling high network capacity wireless cellular system is been proposed. FD-MIMO provide beam control in azimuth and elevation plane using active antenna system (AAS) to take advantage of 3D-MIMO techniques such as 3D beamforming. It is therefore necessary to characterize and model channel parameters in 3D domain rather than the current 2D domain used for today’s cellular systems. In this work, using the REMCOM Wireless Insite X3D ray tracing engine, we characterize the mmWave MIMO channel at 28 GHz center frequency and 100 MHz bandwidth in terms of the angular spread (AS) using a 4 x 4 cross-polarized uniform planar array (UPA) at the base station and 2 x 2 MIMO antenna at the small cell receivers. Two scenarios were considered which are the street canyon and the high-rise. We provide 3D models for angular spread of arrival (at the receiver) and departure (at the base station). We obtain the cross-correlation coefficients of the parameters and analyze the effect of BS-UE height on AS.