Event-Triggered Synchronization for Mobile Distributed Transmit Beamforming
Event-Triggered Synchronization for Mobile Distributed Transmit Beamforming
复制标题
移动分布式发射波束形成的事件触发同步
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Stephen Leak
中科院分区：
文献类型：
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作者：
D. Kramarev;I. Ahmad;Kelvin J. Layton;Marc Lavenant;H. Soetiyono;G. Lechner;Hajime Suzuki;I. Grivell;Stephen Leak
分布式发射波束赋形使接收功率增加了$N^{2}$，其中$N$发射机形成了虚拟天线阵列，但它要求发射机在不共享公共有线时钟参考的情况下进行同相同步。建立这种同步的一种流行方法是基于接收机通过低速率反馈信道周期性地提供关于每个单独发射机的相位和可能的频率偏移的反馈。在这项工作中，我们提出了一种新的相位和频率同步方案，当接收端检测到异步超过允许的限制时，以非周期的方式执行同步。然后，我们在软件无线电中对所提出的方案进行了原型设计，并通过现场测试对其性能进行了评估。即使在接收机移动的情况下，该方案也显著降低了对反馈信道带宽的需求，同时保持了足够的相位和频率同步，以达到理论上预测的接收信噪比(SNR)改善。
Distributed transmit beamforming offers $N^{2}$ -fold increase of the received power with $N$ transmitters forming a virtual antenna array, however, it requires the transmitters to be synchronized in-phase without sharing a common wired clock reference. One popular approach to establish such synchronization is based on the receiver periodically providing feedback on phase and possibly frequency offsets of each individual transmitter through a low-rate feedback channel. In this work, we propose a new phase- and frequency-synchronization scheme performing synchronization in an aperiodic manner, when the receiver detects the asynchrony has exceeded allowed limits. We then prototype the proposed scheme in software-defined radio and evaluate its performance with field trials. The proposed scheme significantly reduces the demand for feedback channel bandwidth even when a receiver is mobile, while keeping the phase and frequency synchronization sufficient to achieve the received signal-to-noise ratio (SNR) improvement predicted theoretically.