Adaptive Beamwidth Control for UAV mm Wave Communications Under Jittering Effects

The high-frequency jitter of the unmanned aerial vehicle (UAV) can lead to severe beam misalignment, and therefore is a critical issue in the UAV millimeter wave (mmWave) communication systems. In this paper, we propose an adaptive beamwidth control scheme for the UAV mmWave communication systems to mitigate the impacts of UAV jitter. To this end, we first characterize the relationship between beamwidth and antenna gain. Based on which, we derive a compact analytical expression for the average transmission rate under jittering effects, enabling us to determine the optimal beamwidth that achieves the maximum average transmission rate of our considered system. In addition, we derive an upper bound of the optimal beamwidth. Through numerical results, we show how our proposed scheme is robust to UAV jitter and can achieve comparable performance as that of the scenario without jitter, when the scale of UAV jitter is moderate.