Analysis of human-body blockage in urban millimeter-wave cellular communications

TLDR

Millimeter‑wave bands are highly susceptible to blockage by obstacles such as foliage, vehicles, and humans, yet analytical models for predicting such effects are scarce. This study introduces a general, tractable model that characterizes human‑induced blockage of mmWave propagation as a function of transmitter–receiver geometry, human density, and dimensions. The model is validated through ray‑launcher simulations that emulate realistic urban environments. Results show that blockage probability rises with human density and Tx–Rx separation, and reveal an optimal transmitter antenna height that maximizes received signal strength depending on distance and device dimensions.

Abstract

The use of extremely high frequency (EHF) or millimeter-wave (mmWave) band has attracted significant attention for the next generation wireless access networks. As demonstrated by recent measurements, mmWave frequencies render themselves quite sensitive to “blocking” caused by obstacles like foliage, humans, vehicles, etc. However, there is a dearth of analytical models for characterizing such blocking and the consequent effect on the signal reliability. In this paper, we propose a novel, general, and tractable model for characterizing the blocking caused by humans (assuming them to be randomly located in the environment) to mmWave propagation as a function of system parameters like transmitter-receiver locations and dimensions, as well as density and dimensions of humans. Moreover, the proposed model is validated using a ray-launcher tool. Utilizing the proposed model, the blockage probability is shown to increase with human density and separation between the transmitter-receiver pair. Furthermore, the developed analysis is shown to demonstrate the existence of a transmitter antenna height that maximizes the received signal strength, which in turn is a function of the transmitter-receiver distance and their dimensions.