Measurement and modeling of indoor channels in elevation domain for 3D MIMO applications

The 3-dimensional multi-input-multi-output (3D MIMO) scheme is one of the enabling technologies for next generation mobile communications and is expected to increase the capacity considerably by realizing the beamforming in the elevation domain. With the small cell architecture, 3D MIMO may be deployed in indoor environments. Thus 3D spatial measurement and characterization of the indoor channels are critical, which have been rarely conducted. In this paper, indoor channel measurements are performed at 2.6 GHz in typical hall and corridor environments including both line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Using a sounder with two uniform planer antenna arrays, spatial channel responses were captured at about 200 positions. The multipath channel impulse responses (CIR) are extracted and the angle-of-arrival of each propagation path is estimated jointly in azimuth and elevation domains. Then the distributions and models of the incident angles and angular power distribution in the elevation domain are established. Our measurements and proposed models can support the design and simulation of 3D MIMO working in the indoor environment in the next generation cellular networks.