Cars and Trucks as Blockers and Reflectors in Vehicular ISAC Systems: Theory, Measurements, and Applications

Wireless propagation models form the basis for designing and evaluating both vehicular communications systems and vehicular wireless sensing systems as well as <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">integrated sensing and communications</i> (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ISAC</i>) systems. Of particular importance is the reflection from, and blockage by, moving objects such as other cars and trucks. This article discusses the ways in which the reflection and blockage characteristics can be measured, how to characterize them, and what values are typical in the different frequency ranges. We find that at high frequencies, reflections from vehicles tend to be more directional, while blockage by vehicles is more pronounced. All these characteristics influence applications in mono- and bistatic vehicular radars as well as the reliability of vehicular communications.