MIMO Broadcasting for Simultaneous Wireless Information and Power Transfer
MIMO Broadcasting for Simultaneous Wireless Information and Power Transfer
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DOI：
10.1109/twc.2013.031813.120224
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发表时间：
2013-05-01
影响因子：
10.4
通讯作者：
Ho, Chin Keong
中科院分区：
文献类型：
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作者：
Zhang, Rui;Ho, Chin Keong
无线电源传输（WPT）是一种有希望的新解决方案，可为无线网络提供方便，永久的能源供应。实际上，对于短/中/远程应用，可以通过各种技术（例如电感耦合，磁共振耦合和电磁辐射）来实现WPT。在本文中，我们特别考虑启用了启用WPT的EM或无线电信号。由于无线电信号可以同时携带能量以及信息，因此将继续进行有关同时无线信息和电力传输（SWIPT）的统一研究。具体而言，本文研究了由三个节点组成的多输入多输出（MIMO）无线广播系统，其中一个接收器收获能量，另一个接收器与通用发射器发送的信号分开解析信息，所有发射器和接收器可能会配备多个天线。检查了两种情况，其中信息接收器和能量接收器分开，并从发射机中看到不同的MIMO通道，或者共同存在，并从发射机中查看相同的MIMO通道。对于分离的接收者，我们得出了最佳传输策略，以实现最大信息速率与能量传递的不同权衡，这些策略的特征是所谓的速率能量（R-E）区域的边界。对于共同确定的接收器，由于潜在的限制，实用的能量收集接收器尚未直接解码信息，因此我们显示了可实现的R-E区域的外部界限。在此约束下，我们研究了共同确定的接收器案例的两个实用设计，即时间切换和功率分裂，并表征其可实现的R-E区域与外部结合相比。
Wireless power transfer (WPT) is a promising new solution to provide convenient and perpetual energy supplies to wireless networks. In practice, WPT is implementable by various technologies such as inductive coupling, magnetic resonate coupling, and electromagnetic (EM) radiation, for short-/mid-/long-range applications, respectively. In this paper, we consider the EM or radio signal enabled WPT in particular. Since radio signals can carry energy as well as information at the same time, a unified study on simultaneous wireless information and power transfer (SWIPT) is pursued. Specifically, this paper studies a multiple-input multiple-output (MIMO) wireless broadcast system consisting of three nodes, where one receiver harvests energy and another receiver decodes information separately from the signals sent by a common transmitter, and all the transmitter and receivers may be equipped with multiple antennas. Two scenarios are examined, in which the information receiver and energy receiver are separated and see different MIMO channels from the transmitter, or co-located and see the identical MIMO channel from the transmitter. For the case of separated receivers, we derive the optimal transmission strategy to achieve different tradeoffs for maximal information rate versus energy transfer, which are characterized by the boundary of a so-called rate-energy (R-E) region. For the case of co-located receivers, we show an outer bound for the achievable R-E region due to the potential limitation that practical energy harvesting receivers are not yet able to decode information directly. Under this constraint, we investigate two practical designs for the co-located receiver case, namely time switching and power splitting, and characterize their achievable R-E regions in comparison to the outer bound.