论文标题
综合信息和能量传递中的RIS辅助零强度和正规化的零效率
RIS-aided Zero-Forcing and Regularized Zero-Forcing Beamforming in Integrated Information and Energy Delivery
论文作者
论文摘要
本文考虑了一个多安德滕纳阵列基站（BS）和可重构智能表面（RIS）的网络，以向信息用户（IUS）（IUS）和能量用户（EUS）传递信息（EUS）。 RIS连接了IUS和BS之间的连接，因为前者和后者之间没有直接路径。 EUS位于BS附近，以便从BS的高功率信号中有效收集能量，而RIS反射得多的弱信号几乎不影响EUS的收获能量。为了在同一时间槽中为所有用户提供可靠的链接，我们采用了传输时间切换（Transmit-TS）方法，根据这些方法，信息和能量在不同的时间段分数中传递。这使我们能够依靠共轭光束进行能量链接和零正规化/正规化的零式光束（ZFB/RZFB）以及RIS的可编程反射系数（PRC）进行信息链接。我们表明，ZFB/RZFB和PRC仍然可以在其关节设计中分别优化，在该设计中，PRC优化基于迭代闭合形式表达式。然后，我们开发了一种用于解决最大值IU吞吐量优化问题的路径遵循算法，但要根据EUS收获的能量阈值对能量服务的现实限制。我们还提出了一个新的RZFB，以大大改善IUS的吞吐量。
This paper considers a network of a multi-antenna array base station (BS) and a reconfigurable intelligent surface (RIS) to deliver both information to information users (IUs) and power to energy users (EUs). The RIS links the connection between the IUs and the BS as there is no direct path between the former and the latter. The EUs are located nearby the BS in order to effectively harvest energy from the high-power signal from the BS, while the much weaker signal reflected from the RIS hardly contributes to the EUs' harvested energy. To provide reliable links for all users over the same time-slot, we adopt the transmit time-switching (transmit-TS) approach, under which information and energy are delivered over different time-slot fractions. This allows us to rely on conjugate beamforming for energy links and zero-forcing/regularized zero-forcing beamforming (ZFB/RZFB) and on the programmable reflecting coefficients (PRCs) of the RIS for information links. We show that ZFB/RZFB and PRCs can be still separately optimized in their joint design, where PRC optimization is based on iterative closed-form expressions. We then develop a path-following algorithm for solving our max-min IU throughput optimization problem subject to a realistic constraint on the quality-of-energy-service in terms of the EUs' harvested energy thresholds. We also propose a new RZFB for substantially improving the IUs' throughput.
