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A Retrodirective Array Enabled by CMOS Chips for Two-Way Wireless Communication with Automatic Beam Tracking
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作者 Jiacheng Guo Yizhu Shen +2 位作者 Guoqing Dong Zhuang Han Sanming Hu 《Engineering》 SCIE EI CAS CSCD 2024年第6期196-207,共12页
This article proposes and demonstrates a retrodirective array(RDA)for two-way wireless communication with automatic beam tracking.The proposed RDA is enabled by specifically designed chips made using a domestic comple... This article proposes and demonstrates a retrodirective array(RDA)for two-way wireless communication with automatic beam tracking.The proposed RDA is enabled by specifically designed chips made using a domestic complementary metal-oxide semiconductor(CMOS)process.The highly integrated CMOS chip includes a receiving(Rx)chain,a transmitting(Tx)chain,and a unique tracking phaselocked loop(PLL)for the crucial conjugated phase recovery in the RDA.This article also proposes a method to reduce the beam pointing error(BPE)in a conventional RDA.To validate the above ideas simply yet without loss of generality,a 2.4 GHz RDA is demonstrated through two-way communication links between the Rx and Tx chains,and an on-chip quadrature coupler is designed to achieve a nonretrodirective signal suppression of 23 dBc.The experimental results demonstrate that the proposed RDA,which incorporates domestically manufactured low-cost 0.18 lm CMOS chips,is capable of automatically tracking beams covering±40with a reduced BPE.Each CMOS chip in the RDA has a compact size of 4.62 mm^(2) and a low power consumption of 0.15 W.To the best of the authors’knowledge,this is the first research to demonstrate an RDA with a fully customized CMOS chip for wireless communication with automatic beam tracking。 展开更多
关键词 Automatic beam tracking CMOS Retrodirective array two-way communication
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Beamforming Design for IRS-and-UAV-Aided Two-Way Amplify-and-Forward Relay Networks in Maritime IoT
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作者 Wang Xuehui Shu Feng +6 位作者 Wu Yuanyuan Shi Weiping Yan Shihao Zhao Yifan Cheng Qiankun Sun Zhongwen Wang Jiangzhou 《China Communications》 SCIE CSCD 2024年第8期45-61,共17页
In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)ca... In this paper,an intelligent reflecting surface(IRS)-and-unmanned aerial vehicle(UAV)-assisted two-way amplify-and-forward(AF)relay network in maritime Internet of Things(IoT)is proposed,where ship1(S1)and ship2(S2)can be viewed as data collecting centers.To enhance the message exchange rate between S1 and S2,a problem of maximizing minimum rate is cast,where the variables,namely AF relay beamforming matrix and IRS phase shifts of two time slots,need to be optimized.To achieve a maximum rate,a low-complexity alternately iterative(AI)scheme based on zero forcing and successive convex approximation(LC-ZF-SCA)algorithm is presented.To obtain a significant rate enhancement,a high-performance AI method based on one step,semidefinite programming and penalty SCA(ONSSDP-PSCA)is proposed.Simulation results show that by the proposed LC-ZF-SCA and ONS-SDP-PSCA methods,the rate of the IRS-and-UAV-assisted AF relay network surpass those of with random phase and only AF relay networks.Moreover,ONS-SDP-PSCA perform better than LC-ZF-SCA in aspect of rate. 展开更多
关键词 BEAMFORMING maritime Internet of Things phase shift rate performance two-way amplify-and-forward relay unmanned aerial vehicle
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Security-Reliability Analysis and Optimization for Cognitive Two-Way Relay Network with Energy Harvesting
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作者 Luo Yi Zhou Lihua +3 位作者 Dong Jian Sun Yang Xu Jiahui Xi Kaixin 《China Communications》 SCIE CSCD 2024年第11期163-179,共17页
This paper investigates the security and reliability of information transmission within an underlay wiretap energy harvesting cognitive two-way relay network.In the network,energy-constrained secondary network(SN)node... This paper investigates the security and reliability of information transmission within an underlay wiretap energy harvesting cognitive two-way relay network.In the network,energy-constrained secondary network(SN)nodes harvest energy from radio frequency signals of a multi-antenna power beacon.Two SN sources exchange their messages via a SN decode-and-forward relay in the presence of a multiantenna eavesdropper by using a four-phase time division broadcast protocol,and the hardware impairments of SN nodes and eavesdropper are modeled.To alleviate eavesdropping attacks,the artificial noise is applied by SN nodes.The physical layer security performance of SN is analyzed and evaluated by the exact closed-form expressions of outage probability(OP),intercept probability(IP),and OP+IP over quasistatic Rayleigh fading channel.Additionally,due to the complexity of OP+IP expression,a self-adaptive chaotic quantum particle swarm optimization-based resource allocation algorithm is proposed to jointly optimize energy harvesting ratio and power allocation factor,which can achieve security-reliability tradeoff for SN.Extensive simulations demonstrate the correctness of theoretical analysis and the effectiveness of the proposed optimization algorithm. 展开更多
关键词 artificial noise energy harvesting cognitive two-way relay network hardware impairments physical layer security security-reliability tradeoff self-adaptive quantum particle swarm optimization
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Reference-frame-independent quantum key distribution with two-way classical communication
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作者 Chun Zhou Hai-Tao Wang +9 位作者 Yi-Fei Lu Xiao-Lei Jiang Yan-Mei Zhao Yu Zhou Yang Wang Jia-Ji Li Yan-Yang Zhou Xiang Wang Hong-Wei Li Wan-Su Bao 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期146-152,共7页
The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In... The data post-processing scheme based on two-way classical communication(TWCC)can improve the tolerable bit error rate and extend the maximal transmission distance when used in a quantum key distribution(QKD)system.In this study,we apply the TWCC method to improve the performance of reference-frame-independent quantum key distribution(RFI-QKD),and analyze the influence of the TWCC method on the performance of decoy-state RFI-QKD in both asymptotic and non-asymptotic cases.Our numerical simulation results show that the TWCC method is able to extend the maximal transmission distance from 175 km to 198 km and improve the tolerable bit error rate from 10.48%to 16.75%.At the same time,the performance of RFI-QKD in terms of the secret key rate and maximum transmission distance are still greatly improved when statistical fluctuations are considered.We conclude that RFI-QKD with the TWCC method is of practical interest. 展开更多
关键词 quantum key distribution reference-frame-independent two-way classical communication
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Investigating the Efficiency Coefficient of Pile Group in Clay Under Two-Way Lateral Load
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作者 Kooshyar Fadayi ASIABSARY Navid HADIANI +1 位作者 Amir Hossein EGHBALI Seyed Mohammad Ali SADREDDINI 《China Ocean Engineering》 SCIE EI CSCD 2023年第5期819-828,共10页
This research investigates the behavior of a 2×2 pile group under two-directional lateral loads in addition to the vertical load.Through three-dimensional numerical modeling based on Flac 3D software,the study ex... This research investigates the behavior of a 2×2 pile group under two-directional lateral loads in addition to the vertical load.Through three-dimensional numerical modeling based on Flac 3D software,the study examines the total bearing capacity and efficiency coefficient of the pile group,considering factors such as the angle of lateral load,relative pile spacing,and relative stiffness of the pile-soil system.The findings highlight the significance of these factors in understanding and predicting the response of pile groups to changing lateral load directions.The results reveal that increasing the angle of the lateral load from 0°to 45°enhances both the maximum total lateral load and the efficiency coefficient of the pile group.When the relative stiffness of the pile-soil system significantly increases,soil stiffening occurs and reducing the relative spacing of the piles from 7 to 3 times the diameter of the piles diminishes the influence of the pile group.Consequently,the response of the pile group to lateral loads becomes more linear,with only a slight alteration in the maximum total lateral load and the efficiency coefficient when the lateral load is angled from 0°to 45°.Conversely,increasing the relative distance between the piles,specifically from 3 to 7 times the diameter of the piles,amplifies the influence of the pile group.Both the maximum total lateral load and the efficiency coefficient of the pile group exhibit an observed increase.These provide insights for designing pile groups and optimizing their performance under lateral loading conditions. 展开更多
关键词 pile group two-way lateral load load capacity efficiency coefficient Flac 3D
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Secrecy Outage Probability for Two-Way Integrated Satellite Unmanned Aerial Vehicle Relay Networks with Hardware Impairments
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作者 Xiaoting Ren Kefeng Guo 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2515-2530,共16页
In this paper,we investigate the secrecy outage performance for the two-way integrated satellite unmanned aerial vehicle relay networks with hardware impairments.Particularly,the closed-form expression for the secrecy... In this paper,we investigate the secrecy outage performance for the two-way integrated satellite unmanned aerial vehicle relay networks with hardware impairments.Particularly,the closed-form expression for the secrecy outage probability is obtained.Moreover,to get more information on the secrecy outage probability in a high signalto-noise regime,the asymptotic analysis along with the secrecy diversity order and secrecy coding gain for the secrecy outage probability are also further obtained,which presents a fast method to evaluate the impact of system parameters and hardware impairments on the considered network.Finally,Monte Carlo simulation results are provided to show the efficiency of the theoretical analysis. 展开更多
关键词 Integrated satellite unmanned aerial vehicle relay networks two-way unmanned aerial vehicle relay hardware impairments secrecy outage probability(SOP) asymptotic SOP
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Two-way中继系统中的双向中继选择及功率分配策略 被引量:7
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作者 刘通 陈前斌 +1 位作者 唐伦 张力生 《计算机应用研究》 CSCD 北大核心 2010年第7期2697-2699,2703,共4页
通过中继选择和功率分配,可以达到提高two-way中继系统总速率的目的。综合考虑中继节点处的接收信噪比和中继节点到目的节点间的信道增益,提出了two-way AF中继系统中的双向中继选择策略(BRS);同时,在总功率受限的条件下,建立了two-way... 通过中继选择和功率分配,可以达到提高two-way中继系统总速率的目的。综合考虑中继节点处的接收信噪比和中继节点到目的节点间的信道增益,提出了two-way AF中继系统中的双向中继选择策略(BRS);同时,在总功率受限的条件下,建立了two-way AF中继系统中的优化功率分配模型,通过对模型进行数学分析求解,提出了一种自适应的最优功率分配策略(OPA)。仿真结果证明两种策略均能提高系统总速率。 展开更多
关键词 two-way中继 AF 中继选择 功率分配
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Two-way中继系统中基于最小化中断概率的功率分配策略 被引量:3
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作者 刘通 陈前斌 +1 位作者 唐伦 张力生 《计算机应用研究》 CSCD 北大核心 2011年第3期1108-1110,共3页
为了降低Two-way中继系统中断概率,提出了一种Two-way中继系统中基于最小化中断概率的功率分配策略。首先推导了Two-way中继系统中断概率的闭合表达式,然后在总功率受限的条件下,提出了一种最小化中断概率的最优功率分配策略(OPA),通过... 为了降低Two-way中继系统中断概率,提出了一种Two-way中继系统中基于最小化中断概率的功率分配策略。首先推导了Two-way中继系统中断概率的闭合表达式,然后在总功率受限的条件下,提出了一种最小化中断概率的最优功率分配策略(OPA),通过拉格朗日乘数法对该优化模型进行了求解。仿真结果证明了该策略能够有效降低系统的中断概率,提高系统性能。 展开更多
关键词 two-way中继 中断概率 功率分配
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3D Two-way Coupled TEHD Analysis on the Lubricating Characteristics of Thrust Bearings in Pump-turbine Units by Combining CFD and FEA 被引量:4
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作者 ZHAI Liming LUO Yongyao +1 位作者 WANG Zhengwei LIU Xin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第1期112-123,共12页
The thermal elastic hydro dynamic (TEHD) lubrication analysis for the thrust bearing is usually conducted by combining Reynolds equation with finite element analysis (FEA). But it is still a problem to conduct the... The thermal elastic hydro dynamic (TEHD) lubrication analysis for the thrust bearing is usually conducted by combining Reynolds equation with finite element analysis (FEA). But it is still a problem to conduct the computation by combining computational fluid dynamics (CFD) and FEA which can simulate the TEHD more accurately. In this paper, by using both direct and separate coupled solutions together, steady TEHD lubrication considering the viscosity-temperature effect for a bidirectional thrust bearing in a pump-turbine unit is simulated combining a 3D CFD model for the oil film with a 3D FEA model for the pad and mirror plate. Cyclic symmetry condition is used in the oil film flow as more reasonable boundary conditions which avoids the oil temperature assumption at the leading and trailing edge. Deformations of the pad and mirror plate are predicted and discussed as well as the distributions of oil film thickness, pressure, temperature. The predicted temperature shows good agreement with measurements, while the pressure shows a reasonable distribution comparing with previous studies. Further analysis of the three-coupled-field reveals the reason of the high pressure and high temperature generated in the film. Finally, the influence of rotational speed of the mirror plate on the lubrication characteristics is illustrated which shows the thrust load should be balanced against the oil film temperature and pressure in optimized designs. This research proposes a thrust bearing computation method by combining CFD and FEA which can do the TEHD analysis more accurately. 展开更多
关键词 PUMP-TURBINE thrust bearing TEHD lubrication two-way coupled CFD FEA
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Buckling-controlled two-way shape memory effect in a ring-shaped bilayer 被引量:4
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作者 Hao Li Xiaoyan Liang Weibin Song 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第6期1217-1225,共9页
Shape memory polymers(SMPs)usually have a one-way shape memory effect.In this paper,an easy-operating method to realize a two-way shape memory effect was demonstrated in a ring-shaped bilayer structure where the two l... Shape memory polymers(SMPs)usually have a one-way shape memory effect.In this paper,an easy-operating method to realize a two-way shape memory effect was demonstrated in a ring-shaped bilayer structure where the two layers are SMPs with different thermal transition temperatures.By designing specific thermomechanical processes,the mismatched deformation between the two layers leads to a morphology change of ring-shaped bilayer structures from a smooth ring to a gear-like buckling shape under cooling and a reversible recovery to the smooth shape under heating.Such a morphology change is ascribed to occurrence and recovery of thermoelastic buckling.This method was validated by finite element simulation.We experimentally investigated the influence of pre-strain on buckling,and it was found that both the buckling occurrence and recovery temperature vary with pre-strain.Furthermore,considering a ring-shaped SMP-SMP bilayer structure,finite element analysis was conducted to study the influence of film thickness and modulus ratio of two layers on buckling behavior.The results showed that the critical buckling wavelength was greatly influenced by film thickness and modulus ratio.W e made a theoretical analysis that accorded well with the numerical results. 展开更多
关键词 Shape memory polymers two-way shape memory effect BUCKLING Ring-shaped BILAYER
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Performance of Physical-Layer Network Coding in Asymmetric Two-Way Relay Channels 被引量:3
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作者 李博 王钢 +3 位作者 Peter H.J.Chong 杨洪娟 Yongliang GUAN 沙学军 《China Communications》 SCIE CSCD 2013年第10期65-73,共9页
In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymm... In this paper, we study the performance of physical-layer network coding in asymmetric two-way relay channels using four different cases having different poor channels:phase asymmetry, downlink asymmetry, uplink asymmetry and node asymmetry. The decision and mapping rule for symmetric and asymmetric cases are studied. The performance in terms of bit error rate for each case will be studied and analysed by computer simulation. Analytical and simulation results show that uplink asymmetry is the worst case;intra-phase asymmetry and unreliable uplink channels will more severely affect the performance degradation, which is caused by channel asymmetry. 展开更多
关键词 physical-layer network coding two-way relay channels asymmetric channels bit error rate
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Experimental Study on a Single Layer Two-Way Grid Shell with Tension Members 被引量:3
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作者 Zhonghao Zhang Masumi Fujimoto +1 位作者 Atsuo Takino Katsuhiko Imai 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第4期10-19,共10页
Single layer two-way grid shell with in-plane and out-of-plane tension members is a new type of single-layer latticed shell roofs. Compared with traditional single-layer latticed shells,this new type has a unique mesh... Single layer two-way grid shell with in-plane and out-of-plane tension members is a new type of single-layer latticed shell roofs. Compared with traditional single-layer latticed shells,this new type has a unique mesh form and excellent rigidity. In order to further understand the buckling behaviors of single layer two-way grid cylindrical shell roof with tension members,the buckling experiments have been undertaken to investigate the effect of tension members,in either out-of-plane or in-plane placement. A single layer two-way grid cylindrical shell roof with out-of-plane tension members has been tested under symmetric and asymmetric loading. The tension member placement,the introducing initial axial force to tension members and the load patterns are considered to investigate the buckling behavior. Experimental results indicate that four long out-ofplane tension members work well under symmetrical loading,but only two long out-of-plane tension members work under asymmetrical loading. It can be concluded that the PC bar members used as tension members for this study are useful in the construction of a single layer two-way grid cylindrical shell roof with structural members intersecting at small angles. 展开更多
关键词 single layer two-way grid shell tension members out-of-plane placement buckling behavior truss system
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Simulation and Analysis of China Climate Using Two-Way Interactive Atmosphere-Vegetation Model (RIEMS-AVIM) 被引量:2
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作者 高荣 董文杰 韦志刚 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2008年第6期1085-1097,共13页
In this paper, an Atmosphere-Vegetation Interaction Model (AVIM) is coupled to the Regional Integrated Environment Model System (RIEMS), and a 10-year integration for China is performed using the RIEMS-AVIM. The a... In this paper, an Atmosphere-Vegetation Interaction Model (AVIM) is coupled to the Regional Integrated Environment Model System (RIEMS), and a 10-year integration for China is performed using the RIEMS-AVIM. The analysis of the results of the 10-year integration shows that the characters of the spatial distributions of temperature and precipitation over China are well simulated. The patterns of simulated surface sensible and latent heat fluxes match well with the spatial climatological atlas: the values of winter surface sensible and latent heat fluxes are both lower than climatological values over the whole country. Summer surface sensible heat flux is higher than climatological values in western China and lower in eastern China, while summer surface latent heat flux is higher than climatological values in the eastern and lower in the western. Seasonal variations of simulated temperature and precipitation of RIMES-AVIM agree with those of the observed. Simulated temperature is lower than the observed in the Tibetan Plateau and Northwest China for the whole year, slightly lower in the remaining regions in winter, but consistent with the observed in summer. The simulated temperature of RIEMS-AVIM is higher in winter and lower in summer than that of RIEMS, which shows that the simulated temperature of RIEMS-AVIM is closer to the observed value. Simulated precipitation is excessive in the first half of the year, but consistent with the observed in the second half of the year. The simulated summer precipitation of RIEMS-AVIM has significant improvement compared to that of RIEMS, which is less and closer to the observed value. The interannual variations of temperature and precipitation are also fairly well simulated, with temperature simulation being superior to precipitation simulation. The interannual variation of simulated temperature is significantly correlated with the observed in Northeast China, the Transition Region, South China, and the Tibetan Plateau, but the correlation between precipitation simulation and observation is only significant in Northwest China. 展开更多
关键词 VEGETATION regional model two-way coupling numerical simulation
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Numerical Prediction Methods for Clock Deviation Based on Two-Way Satellite Time and Frequency Transfer Data 被引量:3
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作者 GUO Hairong YANG Yuanxi HE Haibo 《Geo-Spatial Information Science》 2008年第2期143-147,共5页
Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and freq... Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and frequency transfer. A robust equivalent weight is applied, which controls the significant influence of outlying observations. Some conclusions show that the prediction precision of robust estimation is better than that of LS. The prediction precision calculated from smoothed observations is higher than that calculated from sampling observations. As a count of the obvious period variations in the clock deviation sequence, the predicted values of polynomial model are implausible. The prediction precision of spectral analysis model is very low, but the principal periods can be determined. The prediction RMS of 6-hour extrapolation interval is Ins or so, when modified AR model is used. 展开更多
关键词 time prediction time transfer two-way satellite time and frequency transfer
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Performance Analysis of Full-Duplex Based Two-Way Relaying 被引量:2
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作者 Xiaohui Sun Dandan Zhang Xiaoming Dai 《China Communications》 SCIE CSCD 2016年第11期35-48,共14页
Cooperative communication is regarded as a promising technique for improving the reliability of wireless communication links and enhancing the radio coverage simultaneously. Unlike the conventional half-duplex(HD) mod... Cooperative communication is regarded as a promising technique for improving the reliability of wireless communication links and enhancing the radio coverage simultaneously. Unlike the conventional half-duplex(HD) mode relaying techniques,the full-duplex based two-way relaying(FD-TWR) enables data exchanges between two nodes to be completed within a single time-slot,thus resulting in a significant improvement in the spectrum efficiency. In this paper,the channel model of the FD-TWR is first given out,followed by deriving the critical performance metrics,including the received signal-to-interference-plus-noise ratio(SINR),the upper bound of the ergodic capacity and the closedform solution of the proposed FD-TWR under amplify-and-forward(AF) mode. Furthermore,taking the limit of sum-transmit-power into account,we formulate the objective function of the optimal power allocation of FD-TWR as an extreme-value problem by deriving the optimal transmit power for both the source nodes and the relay node. As long as the self-interference(SI) signal in the FD-TWR nodes can be sufficiently suppressed,the proposed scheme is shown to outperform the conventional HD mode in terms of both the ergodic capacity and the outage probability. In addition,regardless of the practical SI power,the proposedFD-TWR is always capable of achieving its best performance with an aid of the proposed optimal power allocation scheme. 展开更多
关键词 full-duplex two-way relaying optimal power allocation ergodic capacity outage probability
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Power Splitting Based SWIPT in Network-Coded Two-Way Networks with Data Rate Fairness:An Information-Theoretic Perspective 被引量:2
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作者 Ke Xiong Yu Zhang +1 位作者 Yueyun Chen Xiaofei Di 《China Communications》 SCIE CSCD 2016年第12期107-119,共13页
This paper investigates the simultaneous wireless information and powertransfer(SWIPT) for network-coded two-way relay network from an information-theoretic perspective, where two sources exchange information via an S... This paper investigates the simultaneous wireless information and powertransfer(SWIPT) for network-coded two-way relay network from an information-theoretic perspective, where two sources exchange information via an SWIPT-aware energy harvesting(EH) relay. We present a power splitting(PS)-based two-way relaying(PS-TWR) protocol by employing the PS receiver architecture. To explore the system sum rate limit with data rate fairness, an optimization problem under total power constraint is formulated. Then, some explicit solutions are derived for the problem. Numerical results show that due to the path loss effect on energy transfer, with the same total available power, PS-TWR losses some system performance compared with traditional non-EH two-way relaying, where at relatively low and relatively high signalto-noise ratio(SNR), the performance loss is relatively small. Another observation is that, in relatively high SNR regime, PS-TWR outperforms time switching-based two-way relaying(TS-TWR) while in relatively low SNR regime TS-TWR outperforms PS-TWR. It is also shown that with individual available power at the two sources, PS-TWR outperforms TS-TWR in both relatively low and high SNR regimes. 展开更多
关键词 two-way relay energy harvesting wireless power transfer data rate fairness network coding
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A Novel Forwarding Method for Full-Duplex Two-Way Relay Networks 被引量:2
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作者 Shuangshuang Han Xiang Cheng Liuqing Yang 《China Communications》 SCIE CSCD 2017年第4期65-72,共8页
An estimate-and-forward(EF) scheme for single-input single-output(SISO) and multiple-input multiple-output(MIMO) full-duplex two-way relay networks is proposed and analyzed. The relay estimates the received signal fro... An estimate-and-forward(EF) scheme for single-input single-output(SISO) and multiple-input multiple-output(MIMO) full-duplex two-way relay networks is proposed and analyzed. The relay estimates the received signal from two terminal nodes by a minimum mean squared error(MMSE) estimation and forwards a scaled version of the MMSE estimate to the destination. The proposed EF outperforms conventional amplify-and-forward(AF) and decode-and-forward(DF) across all signal-to-noise ratio(SNR) region. Because its computational complexity is high for relays with a large number of antennas(large MIMO) and/or high order constellations, an approximate EF scheme, called list EF, are thus proposed to reduce the computational complexity. The proposed list EF computes a candidate list for the MMSE estimate by using a sphere decoder, and it approaches the performance of the exact EF relay at a negligible performance loss. The proposed forwarding approach also could be used to other relay networks, such as half-duplex, one-way or massive MIMO relay networks. 展开更多
关键词 estimate-and-forward full-duplex two-way relay wireless communications
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Measurement-Device-Independent Quantum Key Distribution with Two-Way Local Operations and Classical Communications 被引量:1
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作者 谭勇刚 刘强 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第9期10-13,共4页
Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doub... Measurement-device-independent quantum key distribution (MDI-QKD) is proven to be immune to all the de- tector side channel attacks. With two symmetric quantum channels, the maximal transmission distance can be doubled when compared with the prepare-and-measure QKD. An interesting question is whether the transmission distance can be extended further. In this work, we consider the contributions of the two-way local operations and classical communications to the key generation rate and transmission distance of the MDI-QKD. Our numerical results show that the secure transmission distances are increased by about 12kin and 8 km when the 1 13 and the 2 B steps are implemented, respectively. 展开更多
关键词 QKD MDI is on Measurement-Device-Independent Quantum Key Distribution with two-way Local Operations and Classical Communications EPR QBER of with
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Security of the Decoy State Two-Way Quantum Key Distribution with Finite Resources 被引量:1
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作者 古亚彬 鲍皖苏 +1 位作者 汪洋 周淳 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第4期1-5,共5页
The quantum key distribution (QKD) allows two parties to share a secret key by typically making use of a one-way quantum channel. Howevery the two-way QKD has its own unique advantages, which means the two-way QKD h... The quantum key distribution (QKD) allows two parties to share a secret key by typically making use of a one-way quantum channel. Howevery the two-way QKD has its own unique advantages, which means the two-way QKD has become a focus recently. To improve the practieM performance of the two-way QKD, we present a security analysis of a two-way QKD protocol based on the decoy method with heralded single-photon sources (HSPSs). We make use of two approaches to calculate the yield and the quantum bit error rate of single-photon and two-photon pulses. Then we present the secret key generation rate based on the GLLP formula. The numerical simulation shows that the protocol with HSPSs has an advantage in the secure distance compared with weak coherent state sources. In addition, we present the final secret key by considering the statistical fluctuation of the yield generation rate of the LM05 protocol with finite resources and the error rate. 展开更多
关键词 QKD in IS on of Security of the Decoy State two-way Quantum Key Distribution with Finite Resources with
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Energy efficiency enhancement of two-way amplifier forward relaying with channel estimation error 被引量:1
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作者 师晓晔 葛建华 +1 位作者 李靖 张沉思 《Journal of Central South University》 SCIE EI CAS 2014年第3期987-992,共6页
In order to save energy consumption of two-way amplifier forward(AF) relaying with channel estimation error, an energy efficiency enhancement scheme is proposed in this work. Firstly, through the analysis of two-way A... In order to save energy consumption of two-way amplifier forward(AF) relaying with channel estimation error, an energy efficiency enhancement scheme is proposed in this work. Firstly, through the analysis of two-way AF relaying mode with channel estimation error, the resultant instantaneous SNRs at end nodes is obtained. Then, by using a high SNR approximation, outage possibility is acquired and its simple closed-form expression is represented. Specially, for using the energy resource more efficiently, a low-complexity power allocation and transmission mode selection policy is proposed to enhance the energy efficiency of two-way AF relay system. Finally, relay priority region is identified in which cooperative diversity energy gain can be achieved. The computer simulations are presented to verify our analytical results, indicating that the proposed policy outperforms direct transmission by an energy gain of 3 dB at the relative channel estimation error less than 0.001. The results also show that the two-way AF relaying transmission loses the two-way AF relaying transmission loses its superiority to direct transmission in terms of energy efficiency when channel estimation error reaches 0.03. 展开更多
关键词 AMPLIFY-AND-FORWARD channel estimation error cooperative energy gain energy efficiency outage probability two-way relay
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