Published online by Cambridge University Press: 18 August 2022
Human blockage causes temporal variations to radio channels when a mobile device is in motion and some plane waves constituting the radio channels are blocked by a human body. Even when two sides of communications are static, moving human bodies often shadow some plane waves, leading to time-varying radio channel responses. Shadowing of plane waves due to human bodies makes the shapes of the Doppler spectrum significantly different for the stationary and mobile links. The main task of modeling human blockages is therefore to choose reasonable properties of the blocking objects. This chapter covers human blockage models with different shapes and material properties of the blocking objects, with mathematical representations to estimate the shadowing losses in addition to free-space losses of a plane wave.