Robust Beamforming With Multi-Panel Array for mmWave Channels Over Mobility and Blockage

This paper investigates beamforming design with multi-panel arrays for millimeter-wave (mmWave) communications in the presence of channel fluctuations due to user equipment (UE) movement and sudden path blockage. In current commercial mmWave systems, a sharp analog beam is designed to be aligned to a line-of-sight (LoS) path using all antenna elements (full array) to attain high array gain. Although this approach is effective for static channels, it may lead to frequent disconnections of the communication link in actual mmWave environment with temporal fluctuations. Therefore, this paper revisits the design of analog beamforming composed of multi-panel arrays and studies the effectiveness of multiple beams with wide directivity, which are aligned not only to the LoS path but also to non-line-of-sight (NLoS) paths. Computer simulations illustrate the limitations of conventional sharp directive beamforming focused solely on maximizing array gain, and reveal the effectiveness of the proposed multiple beam design with multi-panel array over practical mmWave channels.