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Energy-efficient power allocation for NOMA heterogeneous networks with imperfect CSI

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The Journal of China Universities of Posts and Telecommunications 2022年第1期29卷 102-112页

作者： Song Xin Huang Xue Gao Yiming Qian Haijun School of Computer and Communication Engineering Northeastern University at QinhuangdaoQinhuangdao 066000China

In this paper,an optimal user power allocation scheme is proposed to maximize the energy efficiency for downlink non-orthogonal multiple access(NOMA)heterogeneous networks(HetNets).Considering channel estimation errors and inter-user interference under imperfect channel state information(CSI),the energy efficiency optimization problem is formulated,which is non-deterministic polynomial(NP)-hard and non-convex.To cope with this intractable problem,the optimization problem is converted into a convex problem and address it by the Lagrangian dual method.However,it is difficult to obtain closed-form solutions since the variables are coupled with each other.Therefore,a Lagrangian and sub-gradient based algorithm is proposed.In the inner layer loop,optimal powers are derived by the sub-gradient method.In the outer layer loop,optimal Lagrangian dual variables are obtained.Simulation results show that the proposed algorithm can significantly improve energy efficiency compared with traditional power allocation algorithms.

关键词： heterogeneous networks non-orthogonal multiple access imperfect channel state information power allocation

Joint User Association and Fair Scheduling for Dual Connectivity heterogeneous networks

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China Communications 2023年第1期20卷 171-183页

作者： Haixia Cui Yongliang Du School of Electronics and Information Engineering South China Normal UniversityFoshan 528225China School of Physics and Telecommunication Engineering South China Normal UniversityGuangzhou 510006China

heterogeneous small cell network is one of the most effective solutions to overcome spectrum scarcity for the next generation of mobile networks.Dual connectivity(DC)can improve the throughput for each individual user by allowing concurrent access to two heterogeneous radio networks.In this paper,we propose a joint user association and fair scheduling algorithm(JUAFS)to deal with the resource allocation and load balancing issues for DC heterogeneous small cell networks.Considering different coverage sizes,numbers of users,and quality of experience characteristics of heterogeneous cells,we present a proportional fair scheduling for user association among cells and utilize interference graph to minimize the transmission conflict probability.Simulation results show the performance improvement of the proposed algorithm in spectrum efficiency and fairness comparing to the existing schemes.

关键词： fair scheduling heterogeneous networks dual connectivity interference management

Power Allocation and Antenna Selection for heterogeneous Cellular networks

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China Communications 2023年第8期20卷 220-233页

作者： Lingyi Kong Yulong Zou Yuhan Jiang Jia Zhu School of Telecommunications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China

In this paper,we investigate the system performance of a heterogeneous cellular network consisting of a macro cell and a small cell,where each cell has one user and one base station with multiple antennas.The macro base station(MBS)and the small base station(SBS)transmit their confidential messages to the macro user(MU)and the small user(SU)over their shared spectrum respectively.To enhance the system sum rate(SSR)of MBS-MU and SBS-SU transmission,we propose joint antenna selection combined with optimal power allocation(JAS-OPA)scheme and independent antenna selection combined with optimal power allocation(IAS-OPA)scheme.The JAS-OPA scheme requires to know the channel state information(CSI)of transmission channels and interference channels,while the IAS-OPA scheme only needs to know the CSI of transmission channels.In addition,we carry out the analysis for conventional round-robin antenna selection combined with optimal power allocation(RR-OPA)as a benchmark scheme.We formulate the SSR maximization problem through the power allocation between MBS and SBS and propose iterative OPA algorithms for JAS-OPA,IAS-OPA and RR-OPA schemes,respectively.The results show that the OPA schemes outperform the equal power allocation in terms of SSR.Moreover,we provide the closed-form expression of the system outage probability(SOP)for IAS scheme and RR scheme,it shows the SOP performance can be significantly improved by our proposed IAS scheme compared with RR scheme.

关键词： heterogeneous networks antenna selection inter-interference power allocation

Energy-Efficient Bandwidth and Power Allocation in Relay-Assisted Multi-Layer heterogeneous networks with Energy Harvesting

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Journal of Shanghai Jiaotong university(Science) 2023年第6期28卷 822-830页

作者：高锦程赵宜升陈加法陈忠辉 Fujian Key Laboratory for Intelligent Processing and Wireless Transmission of Media Information College of Physics and Information EngineeringFuzhou UniversityFuzhou 350108China

Aiming at excessive users existing in a pico base station(PBS)in the multi-layer heterogeneous networks,the resource allocation problem of maximizing the energy efficiency of the networks is investigated in this paper.By deploying a relay node with energy harvesting function,the data of some users in the PBS can be transferred to an adjacent idle PBS.The bandwidth and transmitting power of users and the relay node are both considered to formulate the resource allocation optimization problem.The objective is to maximize the energy eficiency of the whole heterogeneous networks under the constraints of the user's minimum data rate and energy consumption.The suboptimal solution is obtained by using the particle swarm optimization(PSO)algorithm and quantum-behaved particle swarm optimization(QPSO)algorithm.Simulation results show that the adopted methods have higher energy efficiency than the conventional fixed power and bandwidth method.In addition,the time complexity of the adopted methods is relatively low.

关键词： energy harvesting heterogeneous networks energy efficiency

Distributed heterogeneous Multi-Agent Optimization with Stochastic Sub-Gradient

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Journal of Systems Science & Complexity 2024年第4期37卷 1470-1487页

作者： HU Haokun MO Lipo CAO Xianbing School of Mathematics and Statistics Central South University School of Mathematics and Statistics Beijing Technology and Business University Research Centre for Agri-Product Quality Traceability Beijing Technology and Business University School of Computer and Artificial Intelligence Beijing Technology and Business University China Food Flavor and Nutrition Health Innovation Center Beijing Technology and Business University

This paper studies the optimization problem of heterogeneous networks under a timevarying topology. Each agent only accesses to one local objective function, which is nonsmooth. An improved algorithm with noisy measurement of local objective functions' sub-gradients and additive noises among information exchanging between each pair of agents is designed to minimize the sum of objective functions of all agents. To weaken the effect of these noises, two step sizes are introduced in the control protocol. By graph theory, stochastic analysis and martingale convergence theory, it is proved that if the sub-gradients are uniformly bounded, the sequence of digraphs is balanced and the union graph of all digraphs is joint strongly connected, then the designed control protocol can force all agents to find the global optimal point almost surely. At last, the authors give some numerical examples to verify the effectiveness of the stochastic sub-gradient algorithms.

关键词： Communication noises distributed stochastic optimization heterogeneous networks sub-gradient measurement noises

A QoE-based cell range expansion scheme in heterogeneous cellular networks

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Science China(Information Sciences) 2015年第8期58卷 157-167页

作者： YUAN TingTing FEI Ze Song LI Na WANG Ni Wei XING Cheng Wen LIU Jia Kang School of Information Science and Engineering Beijing Institute of Technology The Research Institution of China Mobile

Deploying low-power nodes(LPNs) overlaid with Macro cells is a promising strategy to improve the coverage and capacity of cellular systems. Meanwhile, cell range expansion(CRE) scheme is proposed to select a proper serving base station(BS) for users between Macro e Node Bs and LPNs, and then offloading of traffic from Macro cell is made. In this paper, first, we introduce the LPNs deployment strategy and its activation criteria in the heterogeneous system. Then, a quality of experience(Qo E)-based CRE scheme to adjust the coverage area of LPNs adaptively is proposed. Different from the existing CRE schemes, the Qo E values for different users with different services are considered when the users try to select an appropriate serving BS. Finally, simulation results demonstrate that the proposed scheme can improve cell edge user experience for various services as well as overall system performance.

关键词： low power nodes heterogeneous networks cell range expansion quality of experience LTEadvanced

Hybrid event-and time-triggered control for double-integrator heterogeneous networks

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Science China(Information Sciences) 2019年第2期62卷 73-84页

作者： Gaopeng DUAN Feng XIAO Long WANG Center for Systems and Control College of Engineering Peking University Research Institute of Intelligent Control and Systems Harbin Institute of Technology

This paper investigates the state consensus for double-integrator networks under heterogeneous interaction topologies. For double-integrator networks, the setting of heterogeneous topologies means that position and velocity information flows are modeled by two different graphs. The corresponding protocol proposed in this paper is based on edge-event-triggered control. The events based on position information are irrelevant to velocity information and independent of the events based on velocity information. And for different edges, the corresponding events are activated independently of each other. Once an event occurs,the agents connected by the associated edge will sample their corresponding relative state information and update their corresponding controllers. Furthermore, under the presented event-triggering rules, the state consensus of double-integrator networks can be achieved by designing appropriate parameters. In addition,the proposed protocol with the event-triggering rules can effectively improve the system performance and avoid the occurrence of Zeno behaviors. Finally, a simulation example is worked out to verify the theoretical analysis.

关键词： consensus sampled-data control multi-agent systems edge-event-triggered control heterogeneous networks

Energy Efficient Resource Allocation Approach for Renewable Energy Powered heterogeneous Cellular networks

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Computers, Materials & Continua 2020年第7期64卷 501-514页

作者： Yifei Wei Yu Gong Qiao Li Mei Song Xiaojun Wang Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and TelecommunicationsBeijing100867China School of Electronic Engineering Dublin City UniversityDublin9Ireland

In this paper,maximizing energy efficiency(EE)through radio resource allocation for renewable energy powered heterogeneous cellular networks(HetNet)with energy sharing,is investigated.Our goal is to maximize the network EE,conquer the instability of renewable energy sources and guarantee the fairness of users during allocating resources.We define the objective function as a sum weighted EE of all links in the HetNet.We formulate the resource allocation problem in terms of subcarrier assignment,power allocation and energy sharing,as a mixed combinatorial and non-convex optimization problem.We propose an energy efficient resource allocation scheme,including a centralized resource allocation algorithm for iterative subcarrier allocation and power allocation in which the power allocation problem is solved by analytically solving the Karush-Kuhn-Tucker(KKT)conditions of the problem and a water-filling problem thereafter and a low-complexity distributed resource allocation algorithm based on reinforcement learning(RL).Our numerical results show that both centralized and distributed algorithms converge with a few times of iterations.The numerical results also show that our proposed centralized and distributed resource allocation algorithms outperform the existing reference algorithms in terms of the network EE.

关键词： heterogeneous networks energy harvesting energy efficiency resource allocation energy sharing

An enhanced framework for providing multimedia broadcast/multicast service over heterogeneous networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第1期15卷 63-80页

作者： Yi-han XU Chee-Onn CHOW Mau-Luen THAM Hiroshi ISHII Department of Electrical Engineering University of Malaya Professional Graduate School of Embedded Technology Tokai University

Multimedia broadcast multicast service(MBMS)with inherently low requirement for network resources has been proposed as a candidate solution for using such resources in a more efficient manner.On the other hand,the Next Generation Mobile Network(NGMN)combines multiple radio access technologies(RATs)to optimize overall network performance.Handover performance is becoming a vital indicator of the quality experience of mobile user equipment(UE).In contrast to the conventional vertical handover issue,the problem we are facing is how to seamlessly transmit broadcast/multicast sessions among heterogeneous networks.In this paper,we propose a new network entity,media independent broadcast multicast service center(MIBM-SC),to provide seamless handover for broadcast/multicast sessions over heterogeneous networks,by extensions and enhancements of MBMS and media independent information service(MIIS)architectures.Additionally,a network selection scheme and a cell transmission mode selection scheme are proposed for selecting the best target network and best transmission mode.Both schemes are based on a load-aware network capacity estimation algorithm.Simulation results show that the proposed approach has the capability to provide MBMS over heterogeneous networks,with improved handover performance in terms of packet loss rate,throughput,handover delay,cell load,bandwidth usage,and the peak signal-to-noise ratio(PSNR).

关键词： IEEE 802.21 MIBM-SC MBMS MIIS heterogeneous networks Network resource management