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non-orthogonal multiple access in Cell-Free Massive MIMO Networks

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China Communications 2020年第8期17卷 81-94页

作者： Yao Zhang Haotong Cao Meng Zhou Longxiang Yang Department of Wireless Communication Key Lab of Jiangsu Province Nanjing University of Posts and TelecommunicationsNanjing 210003China

In this paper, we investigate the downlink performance of cell-free massive multi-input multi-output non-orthogonal multiple access(CF-m MIMO-NOMA) system with conjugate beamforming precoder and compare against the orthogonal multiple access(OMA) counterpart. A novel achievable closed-form spectral efficiency(SE) expression is derived, which characterizes the effects of the channel estimation error, pilot contamination, imperfect successive interference cancellation(SIC) operation, and power optimization technique. Then, motivated by the closedform result, a sum-SE maximization algorithm with the sequential convex approximation(SCA) is proposed, subject to each AP power constraint and SIC power constraint. Numerical experiments indicate that the proposed sum-SE maximization algorithms have a fast converge rate, within about five iterations. In addition, compared with the full power control(FPC) scheme, our algorithms can significantly improve the achievable sum-SE. Moreover, NOMA outperforms OMA in many respects in the presence of the proposed algorithms.

关键词： non-orthogonal multiple access CF-mMIMO successive interference cancellation power optimization sequential convex approximation

Secure Transmission in Downlink non-orthogonal multiple access Based on Polar Codes

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China Communications 2021年第9期18卷 221-235页

作者： Ce Sun Zesong Fei Bin Li Xinyi Wang Nan Li Lijie Hu School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China Nanjing University of Information Science and Technology Nanjing 210044China China Mobile Research Institute Beijing 100053China

non-orthogonal multiple access(NOMA)is deemed to have a superior spectral efficiency and polar codes have became the channel coding scheme for control channel of enhanced mobile broadband(eMBB)in the fifth generation(5G)communication systems.In this paper,NOMA combined with polar codes is used to achieve secure transmission.Both degraded wiretap channel and non-degraded wiretap channel are considered,where an eavesdropper intercepts the communication between base station(BS)and users.For the degraded wiretap channel scenario,a secure polar encoding scheme is proposed in NOMA systems with power allocation to achieve the maximum secrecy capacity.With regard to the nondegraded wiretap channel,a polar encoding scheme with multiple-input-single-output(MISO)system is proposed,where artificial noise is generated at BS to confuse the eavesdropper’s channel via transmit beamforming.The security and the secure rate are employed respectively in order to measure the secrecy performance.We prove that the proposed schemes for each scenario can achieve the secure rate and can transmit the signal securely and reliably.The simulation results show that the eavesdropper hardly decoding the secure signal when the legitimate receiver can decode the signal with very low block error rate(BLER).

关键词： physical layer security polar codes non-orthogonal multiple access artificial noise

Analysis of non-orthogonal multiple access for 5G

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China Communications 2016年第S2期13卷 52-66页

作者： Yingmin Wang Bin Ren Shaohui Sun Shaoli Kang Xinwei Yue School of Information and Communication Engineering Beijing University of Posts & Telecommunications State Key Laboratory of Wireless Mobile Communications China Academy of Telecommunication Technology National Engineering Laboratory of New Generation Mobile Communication Network and Chip Technology China Academy of Telecommunication Technology School of Electronic and Information Engineering Beihang University

The major challenge faced by the fifth generation(5G) mobile network is higher spectral efficiency and massive connectivity,i.e.,the target spectrum efficiency is 3 times over 4G,and the target connection density is one million devices per square kilometer.These requirements are difficult to be satisfied with orthogonal multiple access(OMA) schemes.non-orthogonal multiple access(NOMA) has thus been proposed as a promising candidate to address some of the challenges for 5G.In this paper,a comprehensive survey of different candidate NOMA schemes for 5G is presented,where the usage scenarios of5 G and the application requirements for NOMA are firstly discussed.A general framework of NOMA scheme is established and the features of typical NOMA schemes are analyzed and compared.We focus on the recent progress and challenge of NOMA in standardization of international telecommunication union(ITU),and 3rd generation partnership project(3GPP).In addition,prototype development and future research directions are also provided respectively.

关键词： 5G non-orthogonal multiple access NOMA SCMA PDMA MUSA MPA SIC

Ultra reliability and massive connectivity provision in integrated internet of military things(IoMT)based on tactical datalink

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Defence Technology（防务技术） 2024年第3期33卷 386-398页

作者： Li Bing Yating Gu Lanke Hu Li Bowen Yang Lihua Jue Wang Yue Yin Northwestern Polytechnical University Xi'an 710072China China Academy of Information and Communications Technology Beijing 100191China China Intelligent and Connected Vehicles(Beijing)Research Institute Co. LtdBeijing 100176China The 20th Research Institute of China Electronic Technology Group Corporation Xi’an 710068China Xidian University Xi'an 710071China

One of the major challenges arising in internet of military things(IoMT)is accommodating massive connectivity while providing guaranteed quality of service(QoS)in terms of ultra-high reliability.In this regard,this paper presents a class of code-domain nonorthogonal multiple accesses(NOMAs)for uplink ultra reliable networking of massive IoMT based on tactical datalink such as Link-16 and joint tactical information distribution system(JTIDS).In the considered scenario,a satellite equipped with Nr antennas servers K devices including vehicles,drones,ships,sensors,handset radios,etc.nonorthogonal coded modulation,a special form of multiple input multiple output(MIMO)-NOMA is proposed.The discussion starts with evaluating the output signal to interference-plus-noise(SINR)of receiver filter,leading to the unveiling of a closed-form expression for overloading systems as the number of users is significantly larger than the number of devices admitted such that massive connectivity is rendered.The expression allows for the development of simple yet successful interference suppression based on power allocation and phase shaping techniques that maximizes the sum rate since it is equivalent to fixed-point programming as can be proved.The proposed design is exemplified by nonlinear modulation schemes such as minimum shift keying(MSK)and Gaussian MSK(GMSK),two pivotal modulation formats in IoMT standards such as Link-16 and JITDS.Numerical results show that near capacity performance is offered.Fortunately,the performance is obtained using simple forward error corrections(FECs)of higher coding rate than existing schemes do,while the transmit power is reduced by 6 dB.The proposed design finds wide applications not only in IoMT but also in deep space communications,where ultra reliability and massive connectivity is a keen concern.

关键词： Satellite network Deep space communications Internet of military things non-orthogonal multiple access MIMO Link-16 JITDS

Cooperative Spectrum Sensing Deployment for Cognitive Radio Networks for Internet of Things 5G Wireless Communication

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Tsinghua Science and Technology 2024年第3期29卷 698-720页

作者： Thulasiraman Balachander Kadiyala Ramana Rasineni Madana Mohana Gautam Srivastava Thippa Reddy Gadekallu SRM Institute of Science and Technology Tamil Nadu 603203India Lebanese American University Beirut 1102Lebanonand also with Chaitanya Bharathi Institute of TechnologyHyderabad 500075India Chaitanya Bharathi Institute of Technology Hyderabad 500075India Brandon University BrandonR7A 0A1CanadaChinaMedical UniversityTaichung 404327Chinaand Lebanese American UniversityBeirut 1102Lebanon Department of Electrical and Computer Engineering Lebanese American UniversityBeirut 1102Lebanon

Recently,Cooperative Spectrum Sensing(CSS)for Cognitive Radio Networks(CRN)plays a significant role in efficient 5G wireless communication.Spectrum sensing is a significant technology in CRN to identify underutilized spectrums.The CSS technique is highly applicable due to its fast and efficient performance.5G wireless communication is widely employed for the continuous development of efficient and accurate Internet of Things(IoT)networks.5G wireless communication will potentially lead the way for next generation IoT communication.CSS has established significant consideration as a feasible resource to improve identification performance by developing spatial diversity in receiving signal strength in IoT.In this paper,an optimal CSS for CRN is performed using Offset Quadrature Amplitude Modulation Universal Filtered Multi-Carrier non-orthogonal multiple access(OQAM/UFMC/NOMA)methodologies.Availability of spectrum and bandwidth utilization is a key challenge in CRN for IoT 5G wireless communication.The optimal solution for CRN in IoT-based 5G communication should be able to provide optimal bandwidth and CSS,low latency,Signal Noise Ratio(SNR)improvement,maximum capacity,offset synchronization,and Peak Average Power Ratio(PAPR)reduction.The Energy Efficient All-Pass Filter(EEAPF)algorithm is used to eliminate PAPR.The deployment approach improves Quality of Service(QoS)in terms of system reliability,throughput,and energy efficiency.Our in-depth experimental results show that the proposed methodology provides an optimal solution when directly compares against current existing methodologies.

关键词： cooperative spectrum sensing cognitive radio network Internet of Things offset quadratureamplitude modulation universal filtered multi-carrier non-orthogonal multiple access

non-orthogonal multiple access Schemes for 5G

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ZTE Communications 2016年第4期14卷 11-16页

作者： YAN Chunlin YUAN Zhifeng LI Weimin YUAN Yifei ZTE Corporation Shengzhen 518057 China

multiple access scheme is one of the key techniques in wireless communication systems. Each generation of wireless communica-tion is featured by a new multiple access scheme from 1G to 4G. In this article we review several non-orthogonal multiple access schemes for 5G. Their principles, advantages and disadvantages are discussed, and followed by a comprehensive comparison of these solutions from the perspective of user overload, receiver type, receiver complexity and so on. We also discuss the applica-tion challenges of non-orthogonal multiple access schemes in 5G.

关键词： 5G non-orthogonal multiple access mMTC

Energy-efficient UAV-NOMA aided wireless coverage with massive connections

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Science China(Information Sciences) 2023年第12期66卷 194-208页

作者： Yuqiao TONG Min SHENG Junyu LIU Nan ZHAO School of Information and Communication Engineering Dalian University of Technology State Key Laboratory of Integrated Services Networks Xidian University

In this paper, we propose an unmanned aerial vehicle(UAV)-assisted wireless coverage scheme,wherein UAVs help to serve the cell-edge users for ground base stations based on non-orthogonal multiple access(NOMA). The combined benefits of wide coverage and massive connections enable UAV-NOMA-aided wireless coverage to effectively meet the requirements of the Internet of Everything. Meanwhile, energy efficiency(EE) is maximized via resource allocation to address the issue of the power supply bottleneck of UAVs. The non-convex optimization problem is transformed into two convex subproblems of trajectory optimization and power allocation, and an iterative alternating optimization algorithm is proposed to address it effectively. Moreover, we further considered the energy consumption of the ground base stations, effectively minimizing it by optimizing precoding while guaranteeing average throughput. Numerical results verify the effectiveness of the proposed UAV-aided wireless coverage scheme and demonstrate the EE improvement.

关键词： energy efficiency non-orthogonal multiple access trajectory optimization unmanned aerial vehicle wireless coverage

Joint multiple resource allocation for offloading cost minimization in IRS-assisted MEC networks with NOMA

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Digital Communications and Networks 2023年第3期9卷 613-627页

作者： Guang Chen Yueyun Chen Zhiyuan Mai Conghui Hao Meijie Yang Shuangshuang Han Liping Du School of Computer and Communication Engineering University of Science and Technology BeijingBeijing100083China Shunde Innovition School of Unversity of Science and Technology Beijing

Effective resource allocation can exploit the advantage of intelligent reflective surface(IRS)assisted mobile edge computing(MEC)fully.However,it is challenging to balance the limited energy of MTs and the strict delay requirement of their tasks.In this paper,in order to tackle the challenge,we jointly optimize the offloading delay and energy consumption of mobile terminals(MTs)to realize the delay-energy tradeoff in an IRS-assisted MEC network,in which non-orthogonal multiple access(NOMA)and multiantenna are applied to improve spectral efficiency.To achieve the optimal delay-energy tradeoff,an offloading cost minimization model is proposed,in which the edge computing resource allocation,signal detecting vector,uplink transmission power,and IRS phase shift coefficient are needed to be jointly optimized.The optimization of the model is a multi-level fractional problem in complex fields with some coupled high dimension variables.To solve the intractable problem,we decouple the original problem into a computing subproblem and a wireless transmission subproblem based on the uncoupled relationship between different variable types.The computing subproblem is proved convex and the closed-form solution is obtained for the edge computing resource allocation.Further,the wireless transmission subproblem is solved iteratively through decoupling the residual variables.In each iteration,the closed-form solution of residual variables is obtained through different successive convex approximation(SCA)methods.We verify the proposed algorithm can converge to an optimum with polynomial complexity.Simulation results indicate the proposed method achieves average saved costs of 65.64%,11.24%,and 9.49%over three benchmark methods respectively.

关键词： Mobile edge computing Intelligent reflective surface Task offloading multiple resource allocation non-orthogonal multiple access

User scheduling and power allocation for downlink multi-cell multi-carrier NOMA systems

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Digital Communications and Networks 2023年第1期9卷 252-263页

作者： Abuzar B.M.Adam Xiaoyu Wan Zhengqiang Wang School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China

In non-orthogonal multiple access(NOMA),the best way to fully exploit the benefits of the system is the efficient resource allocation.For the NOMA power domain,the allocation of power and spectrum require solving the mixed-integer nonlinear programming NP-hard problem.In this paper,we investigate user scheduling and power allocation in Multi-Cell Multi-Carrier NOMA(MCMC-NOMA)networks.To achieve that,we consider Weighted Sum Rate Maximization(WSRM)and Weighted Sum Energy Efficiency Maximization(WSEEM)problems.First,we tackle the problem of user scheduling for fixed power using Fractional Programming(FP),the Lagrange dual method,and the decomposition method.Then,we consider Successive Pseudo-Convex Approximation(SPCA)to deal with the WSRM problem.Finally,for the WSEEM problem,SPCA is utilized to convert the problem into separable scalar problems,which can be parallelly solved.Thus,the Dinkelbach algorithm and constraints relaxation are used to characterize the closed-form solution for power allocation.Extensive simulations have been implemented to show the efficiency of the proposed framework and its superiority over other existing schemes.

关键词： Weighted sum rate Weighted energy efficiency non-orthogonal multiple access Successive pseudo-convex approximation Fractional programming