论文标题
智能反映表面辅助的双基督反向散射网络：联合波束形成和反射设计
Intelligent Reflecting Surface-Assisted Bistatic Backscatter Networks: Joint Beamforming and Reflection Design
论文作者
论文摘要
Bistatic反向散射通信（BackCom）允许被动标签在扩展范围内传输，但要使运营商发射器以高功率传输或部署非常接近标签的代价。在本文中，我们研究了智能反射表面（IRS）的存在如何使Bistatic Backcom系统受益。我们研究了载体发射极的发射功率最小化问题，在该载体发射极中，其发射光束成型矢量与IRS相移共同优化，同时保证了所需的反向Comcom性能。该系统设置中的一个独特功能是通过从运营商发射器到读取器传播的信号所经历的多个IRS反射，这使优化问题高度非convex。因此，我们提出了基于少量最大化和交替优化技术的算法，以获取关节设计的近似解决方案。我们还提出了基于单个相移的连续优化的低复合算法。我们的结果显示，即使具有适度的IRS尺寸，也可以在单标签和多标签系统中节省大量的发电功率，可以将其转化为使用原始传输功率或降低标签对位于近距离范围的载体发射器的依赖的重大范围改进。
Bistatic backscatter communication (BackCom) allows passive tags to transmit over extended ranges, but at the cost of having carrier emitters either transmitting at high powers or being deployed very close to tags. In this paper, we examine how the presence of an intelligent reflecting surface (IRS) could benefit the bistatic BackCom system. We study the transmit power minimization problem at the carrier emitter, where its transmit beamforming vector is jointly optimized with the IRS phase shifts, whilst guaranteeing a required BackCom performance. A unique feature in this system setup is the multiple IRS reflections experienced by signals traveling from the carrier emitter to the reader, which renders the optimization problem highly nonconvex. Therefore, we propose algorithms based on the minorization-maximization and alternating optimization techniques to obtain approximate solutions for the joint design. We also propose low-complexity algorithms based on successive optimization of individual phase shifts. Our results reveal considerable transmit power savings in both single-tag and multi-tag systems, even with moderate IRS sizes, which may be translated to significant range improvements using the original transmit power or a reduction of the reliance of tags on carrier emitters located at close range.
