An analysis of human body shadowing models for ray-tracing radio channel characterization

This paper presents a comparison between human body models which are used to simulate the influence of human body movement in indoor radio propagation channel. These models, designed to be used with the image ray-tracing method, differ themselves on shape (cylinder, cuboid or plate-form), on material (absorbent, conductor or dielectric) and on the calculation method of the diffraction coefficient over the human body (knife-edge model, uniform theory of diffraction (UTD) or null, in case of complete absorption). The analysis was made through comparisons between parameters, like signal attenuation and shadow duration, found through empirical and simulated data, as well as information on system performance while simulating, like processing time and memory required. In order to collect the empirical data, two antennas were positioned in line of sight and the effects of crossing human bodies were recorded. Among ten simulated models the analyses showed that the most satisfactory results were obtained by the model that simulated the human body as a completely absorbent cylinder.