Millimeter-Wave Channel Modeling and Coverage Analysis for Indoor Dense Spaces

Millimeter-wave channel modeling for airplanes, trains, and other in-vehicle environments can be considered jointly as different variations of a general site, namely an indoor dense space (IDS). In this work, by using ray-tracing (RT) simulations, we compare the effect of frame material, user density, and geometry on the channel characteristics at 28, 39, and 60 GHz bands. We observe that temporal and spatial parameters in IDS have unique distributions some depending on the transmitter (TX)-receiver (RX) separation in comparison to the indoor office (IO) channel model. The frame material is the main determining factor of the channel characteristics, while variations in frequency bands and geometries have only a minor impact. We extend our channel modeling effort to MIMO deployment analysis to compare the validity of the proposed model in terms of coverage and spectral efficiency with the IO model. Several dominant angular intervals in the channel cause five times higher spectral efficiency gained by digital beamforming (BF) in comparison to analog BF. We observe that the path loss in IDS is more severe compared with IO, resulting in at least a 50% reduction in the coverage area.