Analysis of E-Band Path Loss and Propagation Mechanisms in the Indoor Environment

Millimeter-wave transceivers will feature massive phased-array antennas whose pencilbeams can be steered toward the angle of arrival of the propagation path having the maximum power, exploiting their high gain to compensate for the greater path loss witnessed in the upper spectrum. For this reason, maximum-power path-loss models, in contrast to conventional ones based on the integrated power from an omnidirectional antenna, may be more relevant. Yet to our knowledge, they do not appear in the literature save for one reference. In this paper, we compare both model types at 83.5 GHz for four indoor environments typical of hotspot deployments in line-of-sight (LOS) and non-LOS conditions up to a range of 160 m. To fit the models, we conducted a measurement campaign with over 3000 different transmitter-receiver configurations using a custom-designed channel sounder capable of extracting the delay and 3-D angle of arrival of the received paths with super-resolution. The models are supported by a detailed analysis of the propagation mechanisms of direct transmission, reflection, and knife-edge diffraction to shed light on their interplay in the E-band regime.