Long-Range Blockage Prediction Based on Diffraction Fringe Characteristics for mmWave Communications

Blockage prediction is significant to support mobility for millimeter wave (mmWave) communications, while the prediction range is limited to centimeters in current work. This letter proposes a long-range blockage prediction scheme leveraging the frequency-dependent diffraction fringe characteristics. Firstly, Fresnel-Kirchhoff diffraction is introduced into a communication blockage scenario to analyze the received power of a mobile terminal. An interesting diffraction phenomenon is found that the received power fluctuates with an increasing amplitude before the blockage occurs, and the fluctuation range is frequency-dependent. Inspired by the diffraction fringe characteristics, a blockage feature (BF) based scheme is proposed to predict an upcoming blockage. Then, long-range mmWave blockage prediction is achieved by leveraging sub-6 GHz BF. Finally, a ray-tracing based simulation is utilized to validate our scheme and blockage prediction range can be extended to several meters.