Experimental Characterization of Millimeter-wave Indoor Propagation Channels at 28 GHz

The increasing requirement for the mobile data traffic accelerates the research of millimeter-wave (mm-wave) for future wireless systems. Accurate characterization of the mmwave propagation channel is fundamental and essential for the system design and performance evaluation. In this paper, we conducted measurement campaigns in various indoor scenarios, including classroom, office and hall scenarios at the frequency bands of 27-29 GHz. The spatial channel characteristics are recorded by using a large-scale uniform circular array (UCA). A high resolution parameter estimation (HRPE) algorithm was applied to estimate the mm-wave spherical propagation parameters i.e., the azimuth angle, elevation angle, delay, source distance and complex amplitude of multipath components (MPCs). With the same measurement system, the channel parameters including decay factor, delay spread, angular spread and line of sight (LOS) power ratio are investigated thoroughly in individual indoor scenarios and compared in different indoor scenarios. Furthermore, the impact of the furniture richness level and indoor geometry on the propagation parameters are also investigated.