Hybrid Ambient Backscatter Communication Systems With Harvest-Then-Transmit Protocols
Hybrid Ambient Backscatter Communication Systems With Harvest-Then-Transmit Protocols
复制标题
具有采集然后传输协议的混合环境反向散射通信系统
DOI：
10.1109/access.2018.2864967
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发表时间：
2018
期刊：
影响因子：
3.9
通讯作者：
Liang Ying-Chang
中科院分区：
文献类型：
--
作者：
Li Dong;Peng Wei;Liang Ying-Chang
在本文中，我们调查和分析的混合环境后向散射（AmBack）计划与收获，然后发送协议。在该方案中，整个传输分为三个阶段（时隙）：能量收集（EH），AmBack和数据传输（DT）。根据AmBack的反射系数（RC）的类型，考虑两种混合方案：可变RC（VRC）和固定RC（FRC）。在VRC方案中，RC随着信道状态信息而变化，并且在第一阶段中收集的能量全部用于DT。另一方面，在FRC方案中，RC被固定为1，并且第一阶段中收集的能量部分地用于覆盖第二阶段中的标签电路操作，并且部分地用于第三阶段中的DT。由此产生的优化问题是凸的VRC计划，但非凸的FRC计划。然而，通过利用凸优化中的最大值原理，我们能够推导出这两种方案的最优解的封闭形式的表达式。为了得到更多的见解，我们还分析了这两种方案的上限性能。仿真结果表明，AmBack/EH-AmBack方案始终能够获得最优性能。
In this paper, we investigate and analyze a hybrid ambient backscatter (AmBack) scheme with harvest-then-transmit protocols. In this scheme, the whole transmission is divided into three phases (time slots): energy harvesting (EH), AmBack, and data transmission (DT). Depending on the type of the reflection coefficient (RC) for AmBack, two hybrid schemes are considered: variable RC (VRC) and fixed RC (FRC). In the VRC scheme, the RC changes with the channel state information, and the harvested energy in the first phase is totally used for DT. On the other hand, in the FRC scheme, the RC is fixed to be one, and the harvested energy in the first phase is in part used to cover the tag circuit operation in the second phase and in part for DT in the third phase. The resulting optimization problem is convex for the VRC scheme, but non-convex for the FRC scheme. However, by utilizing the maximum principle in convex optimization, we are able to derive closed-form expressions for optimal solutions for both schemes. In order to get more insights, we also analyze the upper bound performance of both schemes. Simulation results demonstrate that the AmBack/EH-AmBack scheme can always achieve the optimal performance.