检索结果-内蒙古大学图书馆

IEEE International Conference on Communications (ICC)

作者： Efrem, Christos N. Krikidis, Ioannis Univ Cyprus Dept Elect & Comp Engn Nicosia Cyprus

ISBN: (数字)9781538683477

ISBN: (纸本)9781538683477

Intelligent reflecting surfaces (irss) have emerged as a promising wireless technology for the dynamic configuration of electromagnetic waves. In this context, we study a multi-irs assisted two-way communication system consisting of two users that employ full-duplex (FD) technology. More specifically, we deal with the joint irs location and size (i.e., the number of reflecting elements) optimization in order to minimize an upper bound of system outage probability under various constraints. First, the problem is formulated as a discrete optimization problem and, then, a lower bound on the optimum value is computed by solving a linear-programming relaxation (LPR) problem. Subsequently, we design a polynomial-time greedy algorithm based on the LPR solution. The proposed algorithm always computes a feasible solution for which (a posteriori) performance guarantee can be provided. Finally, numerical simulations demonstrate the superiority of the greedy algorithm compared to a baseline scheme and provide useful comparisons between FD and conventional half-duplex (HD) systems.

关键词： Intelligent reflecting surface (irs) irs deployment full-duplex (FD) communication discrete optimization linear-programming relaxation greedy algorithm

来源：评论

学校读者我要写书评

暂无评论

Joint Base Station and irs deployment for Enhancing Network Coverage: A Graph-Based Modeling and Optimization Approach

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2023年第11期22卷 8200-8213页

作者： Mei, Weidong Zhang, Rui Univ Elect Sci & Technol China Natl Key Lab Sci & Technol Commun Chengdu 611731 Peoples R China Chinese Univ Hong Kong Sch Sci & Engn Shenzhen 518172 Peoples R China Shenzhen Res Inst Big Data Shenzhen 518172 Peoples R China Natl Univ Singapore Dept Elect & Comp Engn Singapore 117583 Singapore

Intelligent reflecting surface (irs) can be densely deployed in complex environment to create cascaded line-of-sight (LoS) paths between multiple base stations (BSs) and users via tunable irs reflections, thereby significantly enhancing the coverage performance of wireless networks. To achieve this goal, it is vital to optimize the deployed locations of BSs and irss in the wireless network, which is investigated in this paper. Specifically, we divide the coverage area of the network into multiple non-overlapping cells and decide whether to deploy a BS/irs in each cell given a total number of BSs/irss available. We show that to ensure the network coverage/communication performance, i.e., each cell has a direct/cascaded LoS path with at least one BS, as well as such LoS paths have the average number of irs reflections less than a given threshold, there is a fundamental trade-off with the deployment cost or the number of BSs/irss needed. To optimally characterize this trade-off, we formulate a joint BS and irs deployment problem based on graph theory, which, however, is difficult to be optimally solved due to the combinatorial optimization involved. To circumvent this difficulty, we first consider a simplified problem with given BS deployment and propose the optimal as well as an efficient suboptimal irs deployment solution to it, by applying the branch-and-bound method and iteratively removing irss from the candidate locations, respectively. Next, an efficient sequential update algorithm is proposed for solving the joint BS and irs deployment problem. Numerical results are provided to show the efficacy of the proposed design approach and optimization algorithms for the joint BS and irs deployment. The trade-off between the network coverage performance and the number of deployed BSs/irss with different cost ratios is also unveiled.

关键词： Intelligent reflecting surface (irs) base station deployment irs deployment network coverage performancecost trade-off graph theory

来源：评论

学校读者我要写书评

暂无评论

Multi-Active/Passive-irs Enabled Wireless Information and Power Transfer: Active irs deployment and Performance Analysis

引用

IEEE COMMUNICATIONS LETTERS 2023年第8期27卷 2217-2221页

作者： Fu, Min Mei, Weidong Zhang, Rui Natl Univ Singapore Dept Elect & Comp Engn Singapore 117583 Singapore Univ Elect Sci & Technol China Natl Key Lab Wireless Communicat Chengdu 611731 Peoples R China Chinese Univ Hong Kong Shenzhen Res Inst Big Data Sch Sci & Engn Shenzhen 518172 Guangdong Peoples R China

Intelligent reflecting surfaces (irss), active and/or passive, can be densely deployed in complex environments to significantly enhance wireless network coverage for both wireless information transfer (WIT) and wireless power transfer (WPT). In this letter, we study the downlink WIT/WPT from a multi-antenna base station to a single-antenna user over a multi-active/passive irs (Airs/Pirs)-enabled wireless link. In particular, we derive the location of the Airs with those of the other Pirss being fixed to maximize the received signal-to-noise ratio (SNR) and signal power at the user in the cases of WIT and WPT, respectively. The derived solutions reveal that the optimal Airs deployment is generally different for WIT versus WPT due to the different roles of Airs-induced amplification noise. Furthermore, both analytical and numerical results are provided to show the conditions under which the proposed Airs deployment strategy yields superior performance to other baseline deployment strategies as well as the conventional all-Pirs enabled WIT/WPT.

关键词： Index Terms- Intelligent reflecting surface (irs) active irs multi-irs reflection irs deployment wireless power transfer

来源：评论

学校读者我要写书评

暂无评论

Joint Passive Beamforming and deployment Design for Dual Distributed-irs Aided Communication

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2023年第10期72卷 13758-13763页

作者： Feng, Jie Zheng, Beixiong You, Changsheng Chen, Fangjiong Zhao, Shiduo Che, Wenquan Xue, Quan South China Univ Technol Sch Elect & Informat Engn Guangzhou 510640 Peoples R China South China Univ Technol Sch Microelect Guangzhou 511442 Peoples R China Southern Univ Sci & Technol Dept Elect & Elect Engn Shenzhen 518055 Peoples R China Sci & Technol Communt Networks Lab Shijiazhuang 050081 Hebei Peoples R China

Intelligent reflecting surface (irs) has emerged as a promising solution to enhance communication performance via passive signal reflection. In this paper, we propose a dual distributed-irs aided communication system, where two irss are deployed in a distributed manner to extend the communication coverage of an access point (AP) to a target area. Specifically, we aim to maximize the worst-case signal-to-noise ratio (SNR) over all locations in the target area by jointly optimizing the passive beamforming and deployment for the two distributed irss. To solve this problem, we propose an efficient two-step algorithm by first designing the irss' passive beamforming optimization given irss' locations and then optimizing the irs deployment. Our simulation results show that given the same total number of reflecting elements, deploying two distributed irss can achieve much better coverage performance than deploying one centralized irs.

关键词： Intelligent reflecting surface (irs) passive beamforming irs deployment beam broadening and flattening

来源：评论

学校读者我要写书评

暂无评论

Multi-Passive/Active-irs Enhanced Wireless Coverage: deployment Optimization and Cost-Performance Trade-off

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2024年第8期23卷 9657-9671页

作者： Fu, Min Mei, Weidong Zhang, Rui Natl Univ Singapore Dept Elect & Comp Engn Singapore 117583 Singapore Univ Elect Sci & Technol China Natl Key Lab Wireless Commun Chengdu 611731 Peoples R China Chinese Univ Hong Kong Shenzhen Res Inst Big Data Sch Sci & Engn Shenzhen 518172 Guangdong Peoples R China

Both passive and active intelligent reflecting surfaces (irss) can be deployed in complex environments to enhance wireless network coverage by creating multiple blockage-free cascaded line-of-sight (LoS) links. In this paper, we study a multi-passive/active-irs (Pirs/Airs) aided wireless network with a multi-antenna base station (BS) in a given region. First, we divide the region into multiple non-overlapping cells, each of which may contain one candidate location that can be deployed with a single Pirs or Airs. Then, we show several trade-offs between minimizing the total irs deployment cost and enhancing the signal-to-noise ratio (SNR) performance over all cells via direct/cascaded LoS transmission with the BS. To reconcile these trade-offs, we formulate a joint multi-Pirs/Airs deployment problem to select an optimal subset of all candidate locations for deploying irs and also optimize the number of passive/active reflecting elements deployed at each selected location to satisfy a given SNR target over all cells, such that the total deployment cost is minimized. However, due to the combinatorial optimization involved, the formulated problem is difficult to be solved optimally. To tackle this difficulty, we first optimize the reflecting element numbers with given Pirs/Airs deployed locations via sequential refinement, followed by a partial enumeration to determine the Pirs/Airs locations. Simulation results show that our proposed algorithm achieves better cost-performance trade-offs than other baseline deployment strategies.

关键词： Signal to noise ratio Costs Reflection Wireless networks Optimization Array signal processing Atmospheric modeling Intelligent reflecting surface (irs) active irs irs deployment network coverage cost-performance trade-off graph theory

来源：评论

学校读者我要写书评

暂无评论

Active and Passive irs Jointly Aided Communication: deployment Design and Achievable Rate

引用

IEEE WIRELESS COMMUNICATIONS LETTERS 2023年第2期12卷 302-306页

作者： Fu, Min Zhang, Rui Natl Univ Singapore Dept Elect & Comp Engn Singapore 117583 Singapore Chinese Univ Hong Kong Shenzhen Shenzhen Res Inst Big Data Shenzhen 518172 Peoples R China

In this letter, we study the wireless point-to-point communication from a transmitter (Tx) to a receiver (Rx), which is jointly aided by an active intelligent reflecting surface (Airs) and a passive irs (Pirs). We consider two practical transmission schemes by deploying the two irss in different orders, namely, Tx?Pirs?Airs?Rx (TPAR) and Tx?Airs?Pirs?Rx (TAPR). Assuming line-of-sight channels, we derive the achievable rates for the two schemes by optimizing the placement of the Airs with the location of the Pirs fixed. Our analysis shows that when the number of Pirs elements and/or the Airs amplification power is small, the Airs should be deployed closer to the Rx in both schemes, and TAPR outperforms TPAR with their respective optimized Airs/Pirs placement. Simulation results validate our analysis and show the considerable performance gain achieved by the jointly optimized Airs/Pirs deployment over the existing benchmarks under the same power and irs element budgets.

关键词： Wireless communication Reflection Radio frequency Atmospheric modeling Simulation Resistance Relays Intelligent reflecting surfaces (irs) active irs double irss irs deployment rate maximization

来源：评论

学校读者我要写书评

暂无评论

irs-Aided Wireless Relaying: deployment Strategy and Capacity Scaling

引用

IEEE WIRELESS COMMUNICATIONS LETTERS 2022年第2期11卷 215-219页

作者： Kang, Zhenyu You, Changsheng Zhang, Rui Natl Univ Singapore Dept Elect & Comp Engn Singapore 117583 Singapore Southern Univ Sci & Technol Dept Elect & Elect Engn Shenzhen 518055 Peoples R China

In this letter, we consider an intelligent reflecting surface (irs)-aided wireless relaying system, where a decode-and-forward relay (R) is employed to forward data from a source (S) to a destination (D), aided by M passive reflecting elements. We consider two practical irs deployment strategies, namely, single-irs deployment where all reflecting elements are mounted on one single irs that is deployed near S, R, or D, and multi-irs deployment where the reflecting elements are allocated over three separate irss which are deployed near S, R, and D, respectively. Under the line-of-sight (LoS) channel model, we characterize the capacity scaling orders with respect to an increasing M for the irs-aided relay system with different irs deployment strategies. For single-irs deployment, we show that deploying the irs near R achieves the highest capacity as compared to that near S or D. While for multi-irs deployment, we propose a practical cooperative irs passive beamforming design which is analytically shown to achieve a larger capacity scaling order than the single-irs deployment (i.e., near R or S/D) when M is sufficiently large. Numerical examples are provided, which validate our theoretical results.

关键词： Intelligent reflecting surface (irs) wireless relay irs deployment passive beamforming capacity scaling order

来源：评论

学校读者我要写书评

暂无评论

Joint irs Location and Size Optimization in Multi-irs Aided Two-Way Full-Duplex Communication Systems

引用

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2023年第10期22卷 6518-6533页

作者： Efrem, Christos N. Krikidis, Ioannis Univ Cyprus Dept Elect & Comp Engn CY-1678 Nicosia Cyprus

Intelligent reflecting surfaces (irss) have emerged as a promising wireless technology for the dynamic configuration and control of electromagnetic waves, thus creating a smart (programmable) radio environment. In this context, we study a multi-irs assisted two-way communication system consisting of two users that employ full-duplex (FD) technology. More specifically, we deal with the joint irs location and size (i.e., the number of reflecting elements) optimization in order to minimize an upper bound of system outage probability under various constraints: minimum and maximum number of reflecting elements per irs, maximum number of installed irss, maximum total number of reflecting elements (implicit bound on the signaling overhead) as well as maximum total irs installation cost. First, the problem is formulated as a discrete optimization problem and, then, a theoretical proof of its NP-hardness is given. Moreover, we provide a lower bound on the optimum value by solving a linear-programming relaxation (LPR) problem. Subsequently, we design two polynomial-time algorithms, a deterministic greedy algorithm and a randomized approximation algorithm, based on the LPR solution. The former is a heuristic method that always computes a feasible solution for which (a posteriori) performance guarantee can be provided. The latter achieves an approximate solution, using randomized rounding, with provable (a priori) probabilistic guarantees on the performance. Furthermore, extensive numerical simulations demonstrate the superiority of the proposed algorithms compared to the baseline schemes. Finally, useful conclusions regarding the comparison between FD and conventional half-duplex (HD) systems are also drawn.

关键词： Intelligent reflecting surface irs deployment full-duplex communication discrete optimization NP-hardness linear-programming relaxation randomized rounding approximation algorithm

来源：评论

学校读者我要写书评

暂无评论

Joint Optimization of irs Location and Passive Beamforming for Enhanced Received Power

IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING

引用

IEEE TRANSACTIONS ON GREEN COMMUNICATIONS AND NETWORKING 2024年第4期8卷 1970-1984页

作者： Rani, Jyotsna Mishra, Deepak Prasad, Ganesh Hossain, Ashraf De, Swades Deka, Kuntal Indian Inst Technol Guwahati Dept Elect & Elect Engn Gauhati 781039 India Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia Natl Inst Technol Silchar Dept Elect & Commun Engn Silchar 788010 India Indian Inst Technol Delhi Dept Elect Engn New Delhi 110016 India Indian Inst Technol Delhi Bharti Sch Telecommun New Delhi 110016 India

Intelligent reflecting surface (irs) has recently emerged as a promising technology for beyond fifth-generation (B5G) networks conceived from metamaterials that smartly tunes the signal reflections via a large number of low-cost passive reflecting elements. However, the irs-assisted communication model and the optimization of available resources needs to be improved further for more efficient communications. This paper investigates the enhancement of received power in an irs-assisted wireless communication by jointly optimizing the phase shifts at the irs elements and its location. Employing the conventional Friss transmission model, the relationship between the transmitted power and reflected power is established. The expression of the received power incorporates the free space loss, reflection loss factor, physical dimension of the irs panel, and radiation pattern of the transmit signal. Also, the expression of reflection coefficient of irs panel is obtained by exploiting the existing data of radar communications. Initially exploring a single irs element within a two-ray reflection model, we extend it to a more complex multi-ray reflection model with multiple irs elements in 3D Cartesian space. The expression of the received power in both the cases is derived in a more tractable form, and then, it is maximized by jointly optimizing the underlying variables, i.e., the irs location and the phase shifts. Further, the optimization of resources are investigated in active irs, multiple access, and joint active and passive beamforming. Numerical insights and performance comparison reveal that joint optimization leads to a substantial 37% enhancement in received power compared to the closest competitive benchmark.

关键词： Optimization Array signal processing Radar Aircraft Reflection coefficient Propagation losses Radar cross-sections Intelligent reflecting surface (irs) passive beamforming Friis transmission model irs deployment

来源：评论

学校读者我要写书评

暂无评论

Double-Active-irs Aided Wireless Communication With Total Amplification Power Constraint

引用

IEEE COMMUNICATIONS LETTERS 2023年第10期27卷 2817-2821页

作者： Li, Xinhao You, Changsheng Kang, Zhenyu Zhang, Yunpu Zheng, Beixiong Southern Univ Sci & Technol Dept Elect & Elect Engn Shenzhen 518055 Peoples R China Natl Univ Singapore Dept Elect & Comp Engn Singapore 119077 Singapore South China Univ Technol Sch Microelect Guangzhou 511442 Peoples R China

In this letter, we consider the downlink communication for a wireless communication system aided by two active intelligent reflecting surfaces (irss), where a multi-antenna base station (BS) serves a single-antenna user via a double-reflection link only. An optimization problem is formulated to maximize the achievable rate by jointly designing the BS beamforming as well as the elements allocation, amplification-power allocation, and placement of the two active irss, subject to a total amplification power constraint. Although this problem is non-convex which is generally difficult to solve, we propose an efficient algorithm to obtain its suboptimal solution by using the approximation and block coordinate descent (BCD) methods. Moreover, we show that the considered double-active-irs aided system attains a linear capacity scaling order only, while it can achieve superior rate performance over the benchmark systems with a single active irs, a single passive irs, or two passive irss when the number of total active elements is not too large.

关键词： Resource management Wireless communication Array signal processing Reflection Signal to noise ratio Downlink Channel models Intelligent reflecting surface (irs) active irs double irss irs deployment

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：