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Performance analysis of active RIS-aided multi-pair full-duplex communications with spatial correlation and imperfect CSI

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Science China(Information Sciences) 2023年第9期66卷 259-273页

作者： Zhangjie PENG Xueya LIU Xue LIU cunhua pan Xianzhe CHEN Hong REN College of Information Mechanical and Electrical Engineering Shanghai Normal University National Mobile Communications Research Laboratory Southeast University

This paper investigates a multi-pair full-duplex(FD) communication system aided by an active reconfigurable intelligent surface(RIS) with spatial correlation and imperfect channel state information(CSI).We apply the linear minimum mean square error(LMMSE) method to estimate the cascaded user-RIS-user channel. The approximation for the sum achievable rate(ACR) is derived in closed form over correlated Rician fading channels. To provide insights in a poor-scattering environment, the sum ACR limits are also given when the Rician factors grow infinite. Subsequently, a method based on a genetic algorithm(GA)is designed for the sum ACR maximization considering the cases of continuous and discrete phase *** results validate the derived results, and present that the sum ACRs in the active RIS system are higher than the passive counterparts with the same power consumption, which indicates the superiority of the active RIS in overcoming the “multiplicative fading” effect.

关键词： RIS active RIS FD communication spatial correlation imperfect CSI

What is the optimal inter-site distance in multi-BS cooperative sensing?

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Science China(Information Sciences) 2024年第12期67卷 331-332页

作者： Zhichu REN Yiming YU Hong REN cunhua pan Jiangzhou WANG National Mobile Communications Research Laboratory Southeast University China Mobile Group Design Institute Co. Ltd.

In the sixth-generation(6G) mobile communication systems, integrated sensing and communication(ISAC) has emerged as a key technology that is promising to be applied in various scenarios such as enhanced positioning, h... 详细信息

关键词： Radar interference

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Weighted sum power maximization for STAR-RIS-aided SWIPT systems with nonlinear energy harvesting

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Science China(Information Sciences) 2024年第10期67卷 343-358页

作者： Weiping SHI cunhua pan Feng SHU Yongpeng WU Jiangzhou WANG Yongqiang BAO Jin TIAN School of Network and Communication Nanjing Vocational College of Information Technology National Mobile Communications Research Laboratory Southeast University School of Information and Communication Engineering Hainan University School of Electronic and Optical Engineering Nanjing University of Science and Technology Shanghai Key Laboratory of Navigation and Location Based Services Shanghai Jiao Tong University School of Engineering University of Kent School of Information and Communication Engineering Nanjing Institute of Technology Engineering School of Networks and Telecommunications Jinling Institute of Technology

The conventional reconfigurable intelligent surface(RIS) is limited to reflecting incident signals,thereby imposing constraints on the placement of the transmitter and receiver, which hinders achieving comprehensive signal coverage across an entire area. This paper investigates a simultaneously transmitting and reflecting(STAR)-RIS-aided simultaneous wireless information and power transfer(SWIPT) system with a nonlinear energy harvesting model under three different RIS transmission protocols: energy splitting(ES),time switching(TS), and mode switching(MS). The objective of this paper is to maximize the weighted sum power(WSP) of all energy harvesting receivers(EHRs) while ensuring fairness in the collected power among them. This is achieved by jointly optimizing the transmit beamforming at the base station(BS)and the transmission and reflection coefficients at the STAR-RIS, subject to rate constraints for information decoding receivers(IDRs), transmit power constraint at the BS, and coefficient constraints of each element at the STAR-RIS corresponding to the three protocols. Solving this optimization problem poses challenges because of the complicated objective function and numerous coupled optimization variables of the ES STAR-RIS. To address this complexity, an efficient alternating optimization(AO) approach is proposed as an iterative solution method that achieves suboptimal results. The AO algorithm is then extended to MS STAR-RIS and TS STAR-RIS. Specifically, for MS STRA-RIS, binary constraints in the STAR-RIS coefficient optimization subproblem are handled using the first-order approximation technique along with the penalty function method. For TS STAR-RIS, apart from optimizing BS transmit beamforming and STAR-RIS coefficients subproblems, the transmission and reflection time allocation of STAR-RIS also needs *** findings demonstrate that compared to conventional RIS-aided systems, utilizing three different protocols in a STAR-RIS-aided sy

关键词： STAR-RIS beamforming SWIPT alternating optimization nonlinear energy harvesting

Energy Efficiency of Distributed Antenna Systems with D2D Communications Under Imperfect CSI

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Journal of Communications and Information Networks 2020年第1期5卷 62-74页

作者： Chunlong He Fangyan Zeng Chiya Zhang cunhua pan Daquan Feng Fu-Chun Zheng Guangdong Key Laboratory of Intelligent Information Processing Shenzhen 518060China School of Electronic and Information Engineering Harbin Institute of TechnologyShenzhen 518055China School of Electronic Engineering and Computer Science Queen Mary University of LondonLondon E14NSUK

In this paper,we investigate the distributed antenna systems(DAS)based on device to device(DASD2D)communications under the imperfect channel state information(CSI).Our aim is to maximize the energy efficiency(EE)of the D2D users equipment(DUE)under the constraints of the maximum transmission power of D2D pairs and the quality of service(QoS)requirements of the cellular user equipment(CUE).The worst-case design is considered so that the QoS of the CUE can be guaranteed for every realization of the CSI error in the ellipsoid *** EE objective function of the optimization problem is non-convex and non-linear,and thus this problem cannot be solved by the traditional optimization *** solve this problem,first we transform it to an EE maximization problem without uncertain parameters by exploiting the Markov and Cauchy-Schwartz *** using the fractional programming theory and difference of convex functions optimization method,the robust EE maximization algorithms based on the hard and soft protection method are developed to maximize the system’s EE performance,***,these two algorithms are designed at the cost of the reduced EE of the ***,in order to further improve the EE performance and make a trade-off between the EE performance and the robustness,the iterative update algorithms for the total power constraint and average interference constraint are developed to maximize the system’s EE performance,*** results demonstrate the effectiveness of the four proposed EE algorithms and illustrate the trade-off between the EE performance and robustness for the iterative update algorithms.

关键词： distributed antenna systems device-todevice communications energy efficiency robust worstcase power allocation imperfect channel state information

Towards Near-Field Communications for 6G:Challenges and Opportunities

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ZTE Communications 2024年第1期22卷 3-15页

作者： LIU Mengyu ZHANG Yang JIN Yasheng ZHI Kangda pan cunhua Southeast University Nanjing 210096China Queen Mary University of London London E14NSUK

Extremely large-scale multiple-input multiple-output(XL-MIMO)and terahertz(THz)communications are pivotal candidate technologies for supporting the development of 6G mobile ***,these techniques invalidate the common assumptions of far-field plane waves and introduce many new *** accurately understand the performance of these new techniques,spherical wave modeling of near-field communications needs to be applied for future ***,the investigation of near-field communication holds significant importance for the advancement of 6G,which brings many new and open research challenges in contrast to conventional far-field *** this paper,we first formulate a general model of the near-field channel and discuss the influence of spatial nonstationary properties on the near-field channel ***,we discuss the challenges encountered in the near field in terms of beam training,localization,and transmission scheme design,***,we point out some promising research directions for near-field communications.

关键词： near-field communications extremely large-scale antenna arrays spatial non-stationarity beam training localization

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User cooperation for IRS-aided secure MIMO systems

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Intelligent and Converged Networks 2022年第1期3卷 86-102页

作者： Gui Zhou cunhua pan Hong Ren Kezhi Wang Kok Keong Chai Kai-Kit Wong School of Electronic Engineering and Computer Science Queen Mary University of LondonLondonE14NSUK. the National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China. Department of Computer and Information Sciences Northumbria UniversityNewcastle upon TyneNE18STUK. Department of Electronic and Electrical Engineering University College LondonLondonWC1E 6BTUK.

An intelligent reflecting surface(IRS)is proposed to enhance the physical layer security in the Rician fading channel wherein the angular direction of the eavesdropper(ED)is aligned with a legitimate user.A two-phase communication system under active attacks and passive eavesdropping is considered in this *** base station avoids direct transmission to the attacked user in the first phase,whereas other users cooperate in forwarding signals to the attacked user in the second phase,with the help of IRS and energy harvesting *** the occurrence of active attacks,an outage-constrained beamforming design problem is investigated under the statistical cascaded channel error model,which is solved by using the Bernstein-type *** average secrecy rate maximization problem for the passive eavesdropping is formulated,which is then addressed by a low-complexity *** numerical results of this study reveal that the negative effect of the ED’s channel error is larger than that of the legitimate user.

关键词： intelligent reflecting surface(IRS) reconfigurable intelligent surface(RIS) robust design energy harvesting physical layer security

STAR-RIS辅助通感算一体化系统波束成形设计

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移动通信 2024年第4期48卷 66-72页

作者：任之初靳亚盛潘存华南京邮电大学贝尔英才学院江苏南京210003 东南大学移动通信国家重点实验室江苏南京210096

为提升无线网络的全域覆盖能力,STAR-RIS作为一种全新的RIS架构被提出。针对未来6G网络通信、感知和计算的需求,研究STAR-RIS辅助的通感算一体化系统。旨在联合优化主动、被动波束成形和计算资源分配,在满足通信和感知性能的同时,提升... 详细信息

为提升无线网络的全域覆盖能力,STAR-RIS作为一种全新的RIS架构被提出。针对未来6G网络通信、感知和计算的需求,研究STAR-RIS辅助的通感算一体化系统。旨在联合优化主动、被动波束成形和计算资源分配,在满足通信和感知性能的同时,提升系统能效。所考虑的优化问题是非凸且强耦合的,难以直接求解。为此,提出一种基于交替优化、闭式分式规划、半正定松弛和连续凸近似的算法求解该问题。仿真结果表明,该算法能够极大提升系统性能。

关键词：同时透射和反射可重构智能超表面通感算一体化波束成形

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燃气-蒸汽联合循环发电余热锅炉烟道均流装置数值模拟与优化

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热力发电 2024年第6期53卷 106-113页

作者：陈俊孙玉柱潘存华秦阳曹蓝田崔运静马培勇祁风雷中国大唐集团科学技术研究总院有限公司华东电力试验研究院安徽合肥231299 合肥工业大学机电产品低碳循环利用技术与装备安徽省重点实验室安徽合肥230002 中国石油大学(华东)机电工程学院山东青岛266580

燃气-蒸汽联合循环发电中燃气轮机与余热锅炉主体经常采用大扩张角过渡段连接,导致下游烟气流动不均匀,影响余热锅炉NOx选择性催化还原烟气脱硝效率。对此,提出通过布置三级导流板来改善烟道内烟气的流动均匀性,并采用计算流体力学模拟... 详细信息

燃气-蒸汽联合循环发电中燃气轮机与余热锅炉主体经常采用大扩张角过渡段连接,导致下游烟气流动不均匀,影响余热锅炉NOx选择性催化还原烟气脱硝效率。对此,提出通过布置三级导流板来改善烟道内烟气的流动均匀性,并采用计算流体力学模拟方法研究过渡段导流板布置形式、安装角度及布置密度等参数对烟道内烟气流动特性的影响规律。结果表明:未设置导流装置时过渡段出现明显漩涡,涡度可达20 m-1,导致烟气流动均匀性差;过渡段安装一级变倾角导流板可显著抑制漩涡的尺寸,安装二级变倾角导流板可显著改善过渡段内烟气流动均匀性,但是烟道后端烟气速度均匀性仍不高,安装三级导流板可同步改善过渡段和烟道内烟气流动均匀性,在换热模块三之后相对速度标准差系数降至2.1%。优化的导流板布置为:一级导流板水平投影长度2.25 m,间距1.20 m,角度15°~30°等差递增;二级导流板水平投影长度1.36 m,间距1.40 m,角度15°~60°等差递增;三级导流板长度0.70 m,间距1.00 m,水平安装。研究结果可为烟气均流装置的设计提供理论指导。

关键词：燃气余热锅炉导流板 CFD 流动均匀性

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低负荷下运行氧量对双切圆锅炉燃烧及NO_(x)生成特性影响的模拟与试验研究

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湖北电力 2023年第4期47卷 64-69页

作者：彭志福韩磊周福潘存华马启磊马仑中国大唐集团科学技术研究总院有限公司华东电力试验研究院安徽合肥231299 华中科技大学煤燃烧重点实验室湖北武汉430074

对某1000 MW双切圆锅炉开展了低负荷下运行氧量(5.6%、6.0%、6.4%)对燃烧及NO_(x)生成特性影响的模拟与试验研究。模拟与现场试验结果一致性较好。模拟结果表明:在低负荷下,运行氧量从5.6%增加到6.0%时,飞灰含碳量显著降低,NO_(x)浓度... 详细信息

对某1000 MW双切圆锅炉开展了低负荷下运行氧量(5.6%、6.0%、6.4%)对燃烧及NO_(x)生成特性影响的模拟与试验研究。模拟与现场试验结果一致性较好。模拟结果表明:在低负荷下,运行氧量从5.6%增加到6.0%时,飞灰含碳量显著降低,NO_(x)浓度有所增加;进一步增加运行氧量到6.4%,飞灰含碳量降低幅度相对较小,NO_(x)有所轻微增加。现场试验结果表明:运行氧量控制在6.0%左右,飞灰含碳量较低且锅炉效率较高,汽温可维持在相对较好水平。综合考虑,实际低负荷运行时,建议将运行氧量控制在6.0%左右,可达到高效低NO_(x)燃烧目的。

关键词： 1000 MW双切圆锅炉运行氧量燃烧特性 NO_(x)