IRS-Enhanced OFDM: Power Allocation and Passive Array Optimization
IRS-Enhanced OFDM: Power Allocation and Passive Array Optimization
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DOI：
10.1109/globecom38437.2019.9014204
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发表时间：
2019-05
期刊：
影响因子：
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通讯作者：
Yifei Yang;Shuowen Zhang;Rui Zhang
中科院分区：
文献类型：
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作者：
Yifei Yang;Shuowen Zhang;Rui Zhang
智能反射面（IRS）技术是未来实现无线通信系统频谱和能量高效的一种新技术。通过自适应地改变入射信号的相位/幅度，从而通过大量的可重新配置的无源反射元件来建立有利的信道响应，IRS能够经济有效地增强其附近的移动的用户的通信性能。在本文中，我们研究了一个IRS增强的正交频分复用（OFDM）系统中，IRS部署，以协助附近的用户和其相关的基站（BS）之间的通信。我们的目标是最大限度地提高下行链路可达速率的用户通过联合优化的发射功率分配在BS和无源阵列的反射系数在IRS。虽然制定的问题是非凸的，因此难以解决，我们提出了一个有效的算法，以获得高品质的次优解，通过交替优化BS的功率分配和IRS的无源阵列系数的迭代方式，沿着与定制的方法进行初始化。仿真结果表明，该设计与没有IRS或其他启发式IRS设计相比，显著提高了OFDM链路速率性能。
Intelligent reflecting surface (IRS) is a promising new technology for achieving spectrum and energy efficient wireless communication systems in the future. By adaptively varying the incident signals' phases/amplitudes and thereby establishing favorable channel responses through a large number of reconfigurable passive reflecting elements, IRS is able to enhance the communication performance of mobile users in its vicinity cost- effectively. In this paper, we study an IRS- enhanced orthogonal frequency division multiplexing (OFDM) system in which an IRS is deployed to assist the communication between a nearby user and its associated base station (BS). We aim to maximize the downlink achievable rate for the user by jointly optimizing the transmit power allocation at the BS and the passive array reflection coefficients at the IRS. Although the formulated problem is non-convex and thus difficult to solve, we propose an efficient algorithm to obtain a high-quality suboptimal solution for it, by alternately optimizing the BS's power allocation and the IRS's passive array coefficients in an iterative manner, along with a customized method for the initialization. Simulation results show that the proposed design significantly improves the OFDM link rate performance as compared to the cases without the IRS or with other heuristic IRS designs.