In this paper,we consider mobile edge computing(MEC)networks against proactive eavesdropping.To maximize the transmission rate,IRS assisted UAV communications are applied.We take the joint design of the trajectory of ...In this paper,we consider mobile edge computing(MEC)networks against proactive eavesdropping.To maximize the transmission rate,IRS assisted UAV communications are applied.We take the joint design of the trajectory of UAV,the transmitting beamforming of users,and the phase shift matrix of IRS.The original problem is strong non-convex and difficult to solve.We first propose two basic modes of the proactive eavesdropper,and obtain the closed-form solution for the boundary conditions of the two modes.Then we transform the original problem into an equivalent one and propose an alternating optimization(AO)based method to obtain a local optimal solution.The convergence of the algorithm is illustrated by numerical results.Further,we propose a zero forcing(ZF)based method as sub-optimal solution,and the simulation section shows that the proposed two schemes could obtain better performance compared with traditional schemes.展开更多
To better understand the community patterns mediated by connectivity in artificial reefs of coastal areas, it is necessary to understand the distribution and coexistence of organisms with artificial reefs area and adj...To better understand the community patterns mediated by connectivity in artificial reefs of coastal areas, it is necessary to understand the distribution and coexistence of organisms with artificial reefs area and adjacent waters. This study was conducted to examine main catches assemblages collected by trawls in Haizhou Bay,which included five habitats: the artificial reef area(AR), aquaculture area(AA), natural area(NA), estuary area(EA) and comprehensive effect area(CEA). The result shows that the total abundances of species in the five habitats were highly different(univariate PERMANOVA: P = 0.001, n = 24), but some species were also unique in their habitat(e.g. Scapharca subcrenata and Glossaulax didyma in AA). The body size distribution of specific species between habitats are different. For Collichthys lucidus, their body size in AR(14.63 cm ± 1.64 cm) and EA(14.3 cm ± 0.85 cm) is higher than that in NA(10.65 cm ± 1.64 cm), CEA(11.28 cm ± 1.85 cm) and AA(12.1 cm ±0.43 cm), which indicates the potential connection from AR to EA mediated by their adult population. We concluded that artificial reefs in AR can be considered key components that have the ability to support species assemblages in adjacent habitats. This study has implications for the conservation and monitoring of species assemblages in coastal areas in terms of that artificial reefs can be applied in different stages of habitat protection implementation and in different combinations of scenarios.展开更多
为了提高无线携能通信(Simultaneous Wireless nformation and Power Transfer,SWIPT)通信系统的安全性,同时克服系统收发机硬件损伤(Hardware Impairments,HIs)的影响,提出一种硬件损伤下的智能反射面(Intelligent Reflecting Surface,...为了提高无线携能通信(Simultaneous Wireless nformation and Power Transfer,SWIPT)通信系统的安全性,同时克服系统收发机硬件损伤(Hardware Impairments,HIs)的影响,提出一种硬件损伤下的智能反射面(Intelligent Reflecting Surface,IRS)辅助的SWIPT系统安全波束成形设计方法.考虑能量接收设备为潜在的窃听者,在基站最大发射功率、最小接收能量和IRS相移约束下,通过联合优化基站波束赋形矢量、人工噪声矢量和IRS的相移矩阵,构建系统安全速率最大化问题.针对该优化问题是非凸的,且优化变量是耦合的,提出一种基于交替优化和半正定松弛的有效算法来次优地解决该问题.仿真结果表明,本文所提算法能够在保障能量需求的同时,提升系统的安全性和抗硬件损伤能力.展开更多
Intelligent reflecting surface(IRS)is a newly emerged and promising paradigm to substantially improve the performance of wireless communications by constructing favorable communication channels via properly tuning mas...Intelligent reflecting surface(IRS)is a newly emerged and promising paradigm to substantially improve the performance of wireless communications by constructing favorable communication channels via properly tuning massive reflecting elements.This paper considers a distributed IRS aided decode-and-forward(DF)relaying system over Nakagami-m fading channels.Based on a tight approximation for the distribution of the received signalto-noise ratio(SNR),we first derive exact closed-form expressions of the outage probability,ergodic capacity,and energy efficiency for the considered system.Moreover,we propose the optimal IRS configuration considering the energy efficiency and pilot overhead.Finally,we compare the performance between the distributed IRS-aided DF relaying and multi-IRS-only systems,and verify the analytical results by using monte carlo simulations.展开更多
基金This work was supported by the Key Scientific and Technological Project of Henan Province(Grant Number 222102210212)Doctoral Research Start Project of Henan Institute of Technology(Grant Number KQ2005)Key Research Projects of Colleges and Universities in Henan Province(Grant Number 23B510006).
文摘In this paper,we consider mobile edge computing(MEC)networks against proactive eavesdropping.To maximize the transmission rate,IRS assisted UAV communications are applied.We take the joint design of the trajectory of UAV,the transmitting beamforming of users,and the phase shift matrix of IRS.The original problem is strong non-convex and difficult to solve.We first propose two basic modes of the proactive eavesdropper,and obtain the closed-form solution for the boundary conditions of the two modes.Then we transform the original problem into an equivalent one and propose an alternating optimization(AO)based method to obtain a local optimal solution.The convergence of the algorithm is illustrated by numerical results.Further,we propose a zero forcing(ZF)based method as sub-optimal solution,and the simulation section shows that the proposed two schemes could obtain better performance compared with traditional schemes.
基金The China Scholarship Council under contract No.202308310175the China Postdoctoral Science Foundation under contract No.E-6005-00-0042-39+6 种基金Postdoctoral Fellowship Program of CPSF under contract No. GZC20231539the Jiangsu Haizhou Bay National Sea Ranching Demonstration Project under contract No. D–8005–18–0188Shanghai Municipal Science and Technology Commission Local Capacity Construction Project under contract No. 21010502200the Science Foundation for Youths of Jiangsu ProvinceChina under contract No. BK20170438the Science and Technology Projects in Nantong under contract No. JC2018014the Social Livelihood Key Projects of Nantong under contract No. MS22021015。
文摘To better understand the community patterns mediated by connectivity in artificial reefs of coastal areas, it is necessary to understand the distribution and coexistence of organisms with artificial reefs area and adjacent waters. This study was conducted to examine main catches assemblages collected by trawls in Haizhou Bay,which included five habitats: the artificial reef area(AR), aquaculture area(AA), natural area(NA), estuary area(EA) and comprehensive effect area(CEA). The result shows that the total abundances of species in the five habitats were highly different(univariate PERMANOVA: P = 0.001, n = 24), but some species were also unique in their habitat(e.g. Scapharca subcrenata and Glossaulax didyma in AA). The body size distribution of specific species between habitats are different. For Collichthys lucidus, their body size in AR(14.63 cm ± 1.64 cm) and EA(14.3 cm ± 0.85 cm) is higher than that in NA(10.65 cm ± 1.64 cm), CEA(11.28 cm ± 1.85 cm) and AA(12.1 cm ±0.43 cm), which indicates the potential connection from AR to EA mediated by their adult population. We concluded that artificial reefs in AR can be considered key components that have the ability to support species assemblages in adjacent habitats. This study has implications for the conservation and monitoring of species assemblages in coastal areas in terms of that artificial reefs can be applied in different stages of habitat protection implementation and in different combinations of scenarios.
文摘为了提高无线携能通信(Simultaneous Wireless nformation and Power Transfer,SWIPT)通信系统的安全性,同时克服系统收发机硬件损伤(Hardware Impairments,HIs)的影响,提出一种硬件损伤下的智能反射面(Intelligent Reflecting Surface,IRS)辅助的SWIPT系统安全波束成形设计方法.考虑能量接收设备为潜在的窃听者,在基站最大发射功率、最小接收能量和IRS相移约束下,通过联合优化基站波束赋形矢量、人工噪声矢量和IRS的相移矩阵,构建系统安全速率最大化问题.针对该优化问题是非凸的,且优化变量是耦合的,提出一种基于交替优化和半正定松弛的有效算法来次优地解决该问题.仿真结果表明,本文所提算法能够在保障能量需求的同时,提升系统的安全性和抗硬件损伤能力.
基金supported in part by National Natural Science Foundation of China under Grant 62371262 and 61971467in part by the Key Research and Development Program of Jiangsu Province of China under Grant BE2021013-1+1 种基金in part by the Qinlan Project of Jiangsu Provincein part by the Scientific Research Program of Nantong under Grant JC22022026
文摘Intelligent reflecting surface(IRS)is a newly emerged and promising paradigm to substantially improve the performance of wireless communications by constructing favorable communication channels via properly tuning massive reflecting elements.This paper considers a distributed IRS aided decode-and-forward(DF)relaying system over Nakagami-m fading channels.Based on a tight approximation for the distribution of the received signalto-noise ratio(SNR),we first derive exact closed-form expressions of the outage probability,ergodic capacity,and energy efficiency for the considered system.Moreover,we propose the optimal IRS configuration considering the energy efficiency and pilot overhead.Finally,we compare the performance between the distributed IRS-aided DF relaying and multi-IRS-only systems,and verify the analytical results by using monte carlo simulations.
