Jittering effects significantly degrade the performance of UAV communications especially in millimeter-wave (mmWave) band. To investigate and mitigate the impacts of UAV jitter to mmWave communications, we firstly model UAV mmWave channel based on the geometric relationship between element antennas of the uniform planar arrays (UPAs) in receiver side and transmitter side, and we incorporate the jittering effects to our channel model through extracting the relationship between UAV attitude & position and angle of arrival (AoA) & angle of departure (AoD) of the UPAs. Then, based on the extracted relationship, we propose to utilize UAV navigation information to obtain a rough estimation of AoA and AoD, and we also analyze the impact of AoA and AoD estimation error to UAV beamforming. Finally, we propose a direction-constrained beam training scheme to refine the AoA/AoD estimation. Particularly, we construct a partially random sensing matrix to measure the channel within a narrow angle range that is centered at the aforementioned rough estimate of AoA/AoD. Numerical results show that our proposed UAV beam training scheme with navigation information is able to fast and accurately estimate the AoA/AoD fluctuation caused by UAV jitter.
翻译:为调查并减轻UAV jitter to mm Wave 通信的影响,我们首先根据统一平面阵列(UPAs)元素天线在接收方和发射方之间的几何关系,对UAAVmm Wave频道进行模拟,并分析AOA和AOD估计错误对UAV Beamforming的影响。最后,我们提出一个定向定点靶式训练计划,以完善AAOA/AOD估计值。特别是,我们建立一个部分随机感测矩阵,以测量以上述对AOA/AAAVA的粗略估计为核心的狭小范围内的频道,以上述对AOA/AAVA的精确估计值为中心,并分析AOAA/AVA的估算误差对UAAA/AVA的精确估计结果。