Coverage and Capacity Impact of Mobility and Human Body Blocking at Millimeter Waves

We investigate the impact human body blocking on the performance of millimeter wave wireless systems in an urban hotspot scenario. The effects of human body blocking at higher frequency bands are expected to be more severe than at traditional cellular bands because of worse signal propagation through the human body. To study the temporal behaviour of signals with blocking in a realistic setting, we employ a video clip of real human activity in a public square to model the spatio-temporal distribution of humans by extracting the locations of the people in each frame of the clip and embedding that information within various environment models in a ray tracing tool. This approach enables us to study the human body blocking effects in the context of realistic pedestrian trajectories taking into account the social interactions among people. We present extensive results from the ray tracing tool on the signal to noise ratio statistics and their temporal variation from multiple transmission points in various environments involving human body blocking. Our results show that maintaining good signal to noise ratio requires frequent switching between transmission points, and joint transmission may be preferred over switching to eliminate handover interruption. Our study also shows that multipath propagation though reflections from structures in the surrounding environment can mitigate to some extent but not eliminate the losses because of human body blocking.