Destination-Feedback Free Distributed Transmit Beamforming Using Guided Directionality
Destination-Feedback Free Distributed Transmit Beamforming Using Guided Directionality
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DOI：
10.1109/tmc.2022.3188602
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发表时间：
2021-08
影响因子：
7.9
通讯作者：
Samer S. Hanna;Enes Krijestorac;D. Cabric
中科院分区：
文献类型：
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作者：
Samer S. Hanna;Enes Krijestorac;D. Cabric
分布式发射波束成形使合作无线电能够充当一个虚拟天线阵列，将其通信范围扩展到单个无线电的能力之外。大多数现有的分布式波束成形方法依赖于目的地无线电发送反馈来调整发射机的信号以进行相干组合。然而，依赖于目的地无线电的反馈将通信范围限制为单个无线电的通信范围。现有的无目的地反馈方法依赖于相位同步和以亚波长精度知道节点位置，这对于安装在高移动性平台（如UAV）上的无线电设备变得不切实际。在这篇文章中，我们提出并演示了一个目的地反馈免费分布式波束成形方法，利用无线电的移动性和粗略的位置信息在一个占主导地位的视线信道。在所提出的方法中，一个无线电设备充当向导，并移动以将其余无线电设备的波束指向目的地。我们指定的无线电的位置要求，并验证其在目的地使用模拟的组合信号的关系。使用软件定义无线电实现了概念验证演示，仅依靠四个无线电的粗略放置，就可以在波束成形方向上实现高达9 dB的SNR改善。
Distributed transmit beamforming enables cooperative radios to act as one virtual antenna array, extending their communications’ range beyond the capabilities of a single radio. Most existing distributed beamforming approaches rely on the destination radio sending feedback to adjust the transmitters’ signals for coherent combining. However, relying on the destination radio's feedback limits the communications range to that of a single radio. Existing destination-feedback-free approaches rely on phase synchronization and knowing the node locations with sub-wavelength accuracy, which becomes impractical for radios mounted on high-mobility platforms like UAVs. In this article, we propose and demonstrate a destination-feedback-free distributed beamforming approach that leverages the radio's mobility and coarse location information in a dominant line-of-sight channel. In the proposed approach, one radio acts as a guide and moves to point the beam of the remaining radios towards the destination. We specify the radios’ position requirements and verify their relation to the combined signal at the destination using simulations. A proof of concept demo was implemented using software defined radios, showing up to 9 dB SNR improvement in the beamforming direction just by relying on the coarse placement of four radios.