Robust High Mobility NLOS UE Beamforming Strategy for Gigantic MIMO

Maintaining robust and stable communication links in high-mobility scenarios is challenging for time-division duplex (TDD) reciprocity-based gigantic MIMO systems due to rapid channel variations, especially in non-line-of-sight (NLOS) conditions. This paper proposes a user equipment (UE) beamforming strategy that enables reliable links in high mobility without additional pilot overhead. The proposed strategy aligns the UE beamforming direction with the travel axis. Our analysis shows that this choice minimizes the Doppler spread of the channel, resulting in improved temporal stability. We evaluate this approach through simulations in scattering-rich environments representative of gigantic MIMO deployments. Numerical results confirm that movement-aligned UE beamforming enhances link robustness, increases achievable data rates, and reduces pilot signaling requirements, thereby lowering UE power consumption. These findings indicate that travel-axis-aligned UE beamforming is a promising method for improving reliability in future high-mobility wireless systems.