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Residual energy based multi-relay selection and power allocation scheme in two-way relay network

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The Journal of China Universities of Posts and Telecommunications 2013年第4期20卷 39-45页

作者： DAI Cui-qin LI Fu-jia ZHANG Zu-fan Chongqing Key Lab of Mobile Communication Technology Chongqing University of Posts and Telecommunications

In this paper, we have proposed a multi-relay selection and power allocation scheme for two-way relay network which aims to maximize the sum-rate of two-way relay system. First, to prolong network lifetime, a multi-relay selection strategy is proposed in which both channel state information （CSI） and remaining energy （RE） are considered. Next, a multi-relay power allocation algorithm based on convex optimization （MRPA-CO） is presented. To reduce the computational complexity, it can be divided into two steps： terminal nodes power allocation （TNPA） and relay nodes power allocation （RNPA）. Simulation results indicate that the proposed relay selection strategy can significantly prolong network lifetime compared to other relay selection strategies which consider CSI only, and the MRPA-CO algorithm has great advantage over equal power allocation （EPA） on sum-rate in two-way relay network.

关键词： two-way relay remaining energy multi-relay selection power allocation sum-rate

Joint Beamforming and Time Switching Designs for Energy-Constrained Cognitive two-way relay Networks

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China Communications 2020年第5期17卷 110-118页

作者： Meijuan Zhang Shibing Zhang Zhihua Bao Wei Wang Xiaoge Zhang Yonghong Chen School of Information Science and Technology Nantong UniversityNantong 226019China Nantong Research Institute for Advanced Communication Technology Nantong 226019China Xinglin College Nantong UniversityNantong 226019China

In this paper, we investigate a joint beamforming and time switching(TS) design for an energy-constrained cognitive two-way relay(TWR) network. In the network, the energy-constrained secondary user(SU) relay employs TS protocol to harvest energy from the signals sent by the circuit-powered primary user(PU) transmitter, and then exploits the harvested energy to perform information forwarding. Our aim is to maximize the sum rate of SUs under the constraints of the data rate of PU, the energy harvesting and the transmit power of the SU relay. To determine the beamforming matrix and TS ratio, we decouple the original non-convex problem into two subproblems which can be solved by semidefinite relaxation and successive convex optimization methods. Furthermore, we derive closed form expressions of the optimal solutions for each subproblem, which facilitates the design of a suboptimal iterative algorithm to handle the original sum rate maximization problem. Simulation results are presented to illustrate the effectiveness and superior performance of the proposed joint design against other conventional schemes in the literature.

关键词： cognitive networks two-way relay sum rate energy harvesting beamforming

Performance evaluation of a two-way relay network with energy harvesting^and hardware noises

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Digital Communications and Networks 2021年第1期7卷 45-54页

作者： Nguyen Tien Tung Pham Minh Nam Phu Tran Tin Faculty of Electronics Technology Industrial University of Ho Chi Minh CityHo Chi Minh CityVietnam Wireless Communcations Research Group Faculy of Electrical and Electronics EngineeringTon Duc Thang UniversityHo Chi Minh CityVietnam

In this paper,we propose a two-way Cognitive relay Network(TWCRN)where the secondary users operate on an underlay mode to access the licensed *** the proposed protocols,two secondary sources transmit their data to a relay in the first time slot,and then the relay would forward the received information to both sources in the remaining ***,the relay is self-powered by harvesting energy from ambient Radio Frequency(RF)signals,using the Time Switching(TS)and the Power Switching(PS)*** paper concentrates on eval-uating the performance of the secondary networks under the impact of hardware impairments and co-channel interference from the primary *** particular,based on the secondary transmitters'constraint power,we derive the closed-form expressions of the outage probability and the throughput over Rayleigh fading channels in two cases:TS and *** also investigate the energy efficiency issue and the locally optimal position of the relay to maximize the system throughput,which provides much information to install the relay ***,our derivations are verified by Monte Carlo simulation.

关键词： Energy harvesting two-way relay Energy efficiency Hardware impairments Cognitive network

Joint Subcarrier and Power Allocation for DF-Based Multiuser two-way relay Networks

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China Communications 2017年第6期14卷 179-188页

作者： Xiang Chen Fei He Limin Xiao Shidong Zhou School of Electronics and Information Technology SYSU-CMU Shunde International Joint Research Institute Sun Yat-sen Univ.Guangzhou 510006 China Key Lab of EDA Research Institute of Tsinghua University in Shenzhen Shenzhen 518057 China China Academy of Electronics and Information Technology Beijing 100041 China EE Department Research Institute of Information Technology TNList Tsinghua University Beijing 100084 China

two-way decode-and-forward(DF) relay technique is an efficient method to improve system performance in 5G ***,traditional orthogonal frequency division multiplexing(OFDM) based two-way relay systems only consider a per-subcarrier relay strategy,which treats each subcarrier as a separate channel,which results in significant sum rate loss,especially in fading *** this paper,a joint coding scheme over multiple subcarriers is involved for multipair users in two-way relay systems to obtain multiuser diversity.A generalized subcarrier pairing strategy is proposed to permit each user-pair to occupy different subcarriers during the two transmission phases,i.e.,the multiple access and broadcast ***,a low complexity joint resource allocation scheme is proposed to improve the spectrum efficiency with an additional multi-user diversity *** numerical simulations are finally provided to verify the efficacy of our proposal.

关键词： two-way relay orthogonal frequency division multiplexing (OFDM) decode-and-forward (DF) power allocation

A Novel Forwarding Method for Full-Duplex two-way relay Networks

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China Communications 2017年第4期14卷 65-72页

作者： Shuangshuang Han Xiang Cheng Liuqing Yang The State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of SciencesBeijing China and Qingdao Academy of Intelligent Industries The State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Department of Electrical and Computer Engineering Colorado State University

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.

关键词： estimate-and-forward full-duplex two-way relay wireless communications

Optimal Power Control for OFDM Signals over two-way relay with Physical Network Coding

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Tsinghua Science and Technology 2011年第6期16卷 569-575页

作者： Dingcheng Yang Zhenghai Wang Hao He Jisheng Xu School of Electronic Information Wuhan University Wuhan 430079 China

This paper describes an optimal power allocation scheme for orthogonal frequency division multiple access two-way relay networks with physical network coding. The aim is to enhance the achievable sum rate of the terminals for a constrained total transmit power. Convex optimization is used to derive a closed-form solution for the power allocation between the relay node and the two terminals. This reduces the variable dimensionality of the objective function for the power assignment problem among multiple carriers when the total transmit power is constrained. This solution is then used to derive the optimal power control scheme. This method reduces the implementation complexity compared with the traditional resource allocation scheme. Numerical and simulation results show that the approach achieves almost the optimal sum rate and outperforms the fixed power assignment method with less computational load in various scenarios.

关键词： resource allocation power control two-way relay physical network coding orthogonal frequency division multiple access (OFDMA)

The Average Achievable Rate of Multi-Antenna two-way relay Networks with Interference Alignment

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China Communications 2020年第6期17卷 121-130页

作者： Xue Jiang Baoyu Zheng Weiping Zhu Lei Wang Xiaoyun Hou Nanjing University of Posts and Telecommunications Nanjing 210003China Department of Electrical and Computer Engineering Concordia UniversityMontrealQCCanada H3G 1M8

The large system analysis(LSA)has recently been shown to be a very useful tool for computing the average achievable *** this paper,we use LSA to derive the users’average achievable rate of multi-antenna two-way relay networks with interference alignment(IA),and we then derive the rate expressions under both equal power allocation and optimal power *** is shown that the obtained closed-form rate expressions are functions of the average signal-to-noise ratio(SNR)for each data *** simulation studies show that the average achievable rate expressions derived through LSA provide accurate estimates of the average achievable rate for two-way relay networks with interference alignment.

关键词： two-way relay interference alignment large system analysis

Joint Tomlinson-Harashima Source and Linear relay Precoder Design in Amplify-and-Forward Multiple-Input Multiple-Output two-way relay Systems

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Journal of Shanghai Jiaotong university(Science) 2013年第2期18卷 180-185页

作者：钱成张萌罗汉文刘伟 Department of Electronic Engineering Shanghai Jiaotong University

Existing minimum-mean-squared-error (MMSE) transceiver designs in amplified-and-forward (AF) multiple-input multiple-output (MIMO) two-way relay systems all assume a linear precoder at the sources. Non-linear source precoders in such a system have not been considered yet. In this paper, we study the joint design of source Tomlinson-Harashima precoders (THPs), relay linear precoder and MMSE receivers in two-way relay systems. This joint design problem is a highly nonconvex optimization problem. By dividing the original problem into three sub-problems, we propose an iterative algorithm to optimize precoders and receivers. The convergence of the algorithm is ensured since the updated solution is optimal to each sub-problem. Numerical simulation results show that the proposed iterative algorithm outperforms other algorithms in the high signal-to-noise ratio (SNR) region.

关键词： multiple-input multiple-output (MIMO) two-way relay Tomlinson-Harashima precoding minimum- mean-square-error (MMSE)

Resource allocation for multiuser two-way OFDMA relay networks with user rate constraints

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The Journal of China Universities of Posts and Telecommunications 2011年第3期18卷 54-61页

作者： YANG Ding-cheng XU Ji-sheng HU Shu-kai School of Electronic Information Wuhan University Wuhan 430079 China The State Key Lab of ISN Xidian University Xi'an 710126 China

This paper studies the resource allocation for a multi-user two-way amplify-and-forward （AF） relay network over orthogonal frequency-division multiplexing （OFDM） technology, where all users communicate with their pre-assigned partners. Using convex optimization techniques, an optimal solution to minimize the total transmit power while satisfy each user-pair＇s data rate requirements is proposed. We divide the resource allocation problem into two subproblems：（1） power optimization within user-pair and relay in each subcarrier. （2） optimal subcarrier allocation and sum power assignment among N parallel OFDM subcarriers. Closed-form expressions of the power among user-pair and relay can be obtained in subproblem （1）, and so the proposed algorithm decreases the variable dimensionality of the objective function to reduce the complexity of this optimization problem. To solve it, a three-step suboptimal approach is proposed to assign the resources to user-pairs： Firstly, decompose each user-pair into two sub user-pairs which have one-way and two-way relaying transmission modes. Secondly, allocate the subcarriers to the new mode user-pairs and assign the transmit power to each carrier. Thirdly, distribute the assigned power to three nodes allocated in the subcarrier. Simulation results demonstrate the significant power is saved with the proposed solutions, as compared to a fixed subcarrier allocation.

关键词： resource allocation convex optimization two-way relay amplify and forward multiuser dual decomposition orthogonal frequency-division multiplexingaccess (OFDMA)