Millimeter-Wave Human Blockage at 73 GHz with a Simple Double Knife-Edge Diffraction Model and Extension for Directional Antennas

TL;DR

This study investigates millimeter-wave human blockage at 73 GHz in indoor environments, demonstrating the impact of directional antennas and proposing a simple DKED-based model to predict shadowing effects caused by moving humans.

Contribution

It introduces a straightforward double knife-edge diffraction model for human blockage at 73 GHz, extending previous models to account for directional antenna effects in millimeter-wave links.

Findings

High shadowing attenuation is influenced by antenna directivity and human presence.

Directional antennas require beam switching to mitigate blockage effects.

The proposed DKED model effectively predicts human-induced shadowing at 73 GHz.

Abstract

This paper presents 73 GHz human blockage measurements for a point-to-point link with a 5 m transmitter-receiver separation distance in an indoor environment, with a human that walked at a speed of approximately 1 m/s at a perpendicular orientation to the line between the transmitter and receiver, at various distances between them. The experiment measures the shadowing effect of a moving human body when using directional antennas at the transmitter and receiver for millimeter-wave radio communications. The measurements were conducted using a 500 Megachips-per-second wideband correlator channel sounder with a 1 GHz first null-to-null RF bandwidth. Results indicate high shadowing attenuation is not just due to the human blocker but also is due to the static directional nature of the antennas used, leading to the need for phased-array antennas to switch beam directions in the presence of obstructions and blockages at millimeter-waves. A simple model for human blockage is provided based on the double knife-edge diffraction (DKED) model where humans are approximated by a rectangular screen with infinite vertical height, similar to the human blockage model given by the METIS project.