Modeling and Combating Blockage in Millimeter Wave Systems

There has been substantial interest in understanding the impact of blockage for millimeter wave systems. The 3GPP standard proposes a flat 30 dB blockage model for hand (or self) blockage, and a double knife-edge diffraction (DKED) model-based loss estimation for other humans, vehicles, etc. The 30 dB flat model is based on horn antenna measurements which typically correspond to narrower beamwidths and the DKED model typically assumes omni-antenna measurements. In this work, using measurements from a 28 GHz experimental prototype with phased antenna arrays, we propose more realistic and considerably more optimistic models for hand and body blockage. We also study the time-scales over which millimeter wave links stay coherent and non-degrading due to Doppler and blockage dynamics. We show that dynamic subarray switching provides a reasonable solution to handle these impairments in millimeter wave systems.