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MAKING FULL USE OF OUTDATED CHANNEL ESTIMATES FOR BLOCK BY BLOCK ADAPTIVE MODULATIONS

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Journal of Electronics(China) 2007年第1期24卷 54-59页

作者： Shan Xiaohong Bi Guangguo national mobile commun. research lab Southeast Univ. Nanjing 210005 China

This paper explores the potential to use accurate but outdated channel estimates for adaptive modulation. The work is novel in that the research is conditioned on block by block adaptation. First,we define a new quantity,the Tolerable Average Use Delay (TAUD),which can indicate the ability of an adaptation scheme to tolerate the delay of channel estimation results. We find that for the variable-power schemes,TAUD is a constant and dependent on the target Bit Error Rate (BER),average power and Doppler frequency; while for the constant-power schemes,it depends on the ad-aptation block length as well. At last,we investigate the relation between the delay tolerating per-formance and the spectral efficiency and give the system design criterion. The delay tolerating per-formance is improved at the price of lower data rate.

关键词： Adaptive modulation Block by block adaptation Channel estimation Spectral efficiency

An Advanced Spectrum Allocation Algorithm for The Across-Cell D2D commun.cation in LTE Network with Higher Throughput

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China commun.cations 2016年第4期13卷 30-37页

作者： LI Yun ZHANG Le TAN Xin CAO Bin Chongqing Key lab of mobile commun.cation Technology Chongqing University of Post and Telecommunications(CQUPT) national mobile commun.cations research laboratory Southeast University

In the hybrid LTE cellular network with D2D(Device-to-Device) commun.cation, D2D commun.cation technologies can improve the spectral efficiency significantly. However, the D2D users have to reutilize the spectrum which is allocated to the cellular users. Therefore, the co-channel interference will be more complicated in the case of crosscell D2D commun.cations. In this article, a novel spectrum allocation algorithm for inter-cell D2D commun.cation considering the traffic load is proposed. The traffic load can be balanced by the proposed algorithm. Meanwhile D2D users can multiplex the spectrum allocated to a number of cellular users with a certain percentage to meet the requirements of Qo S of D2D commun.cations and reduce the interference to cellular users. Finally, the simulation results demonstrate that the proposed algorithm can meet the needs of D2D users, balance the traffic load and improve the overall throughput of the system.

关键词： cellular network D2D commun.-cation cross-cell spectrum allocation

Opportunistic access control for enhancing security in D2D-enabled cellular networks

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Science China(Information Sciences) 2018年第4期61卷 187-198页

作者： Yajun CHEN Xinsheng JI Kaizhi HUANG Bin LI Xiaolei KANG national Digital Switching System Engineering & Technological R&D Center national mobile commun.cations research laboratory Southeast University national Engineering lab for mobile Networking Security School of Information and Electronics Beijing Institute of Technology

In this paper, we investigate secure commun.cation over cellular uplinks in device-to-device(D2 D)-enabled cellular networks. We consider a more general scenario, in which multiple D2 D pairs could simultaneously share the same resource block with a specific cellular user. First, an opportunistic access control scheme based on wireless channel gains is proposed, by which the candidate selected set of D2 D pairs sharing the same resource block is determined. The proposed scheme could guarantee reliable commun.cations for both cellular users and D2 D pairs, and further could combat eavesdroppers while keeping the legitimate cellular user as non-intrusive as possible, regarding D2 D pairs as friendly jammers in a non-collaborative way. Then, we derive theoretical results to characterize the security and reliability of the typical cellular and D2 D links, respectively. To further support the performance of this hybrid network, we next present an interference threshold optimization model. Our aim is to minimize the connection outage probability(COP)of D2 D pairs subject to the secrecy requirement of the cellular user. Finally, simulation results are presented to validate the effectiveness of our proposed scheme.

关键词： device-to-device(D2D) commun.cation opportunistic access control physical layer security(PHY-security) secrecy outage probability(SOP) connection outage probability(COP)

Interference-Driven Designs of Nonlinear-Phase FIR Filter with Application in FBMC System

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China commun.cations 2016年第12期13卷 15-24页

作者： Jiangang Wen Jingyu Hua Sunan Li Kai Zhou Dongming Wang College of Information Engineering Zhejiang University of Technology Zhejiang Key lab.commun.Network&Appl. Zhejiang Univ.Tech. national mobile commun.cation research laboratory Southeast University

In the forthcoming 5G systems, new technologies, such as amorphous networks and non-orthogonal filter bank multicarriers(FBMC), provide an effective way to accommodate high-rate transmissions. Meanwhile, the prototype filter affects the adjacent channel interference, and therefore is important for FBMC systems. Besides, once the amorphous network is taken into account, the requirement for interference controlmust be much stricter. Accordingly, this paper focuses on the design of prototype filter with better ability of interference controlling, where we exploit the nonlinear phase FIR filter(NLPFF) instead of traditional linear phase FIR filter(LPFF) to achieve more optimization spaces under a small sacrifice of linear phase. In ourdesigns, both the amplitude and phase responsesare handled independently to approach the stopband performance enhancements, in while the nearly perfect reconstruction(NPR) conditionsare relaxed by pre-specified thresholds. Computer simulations confirm the effectiveness of the NLPFF designs, and demonstrate the advantages of the proposed NLPFF in FBMC applications.

关键词： constrained minimax constrained least-square FBMC nonlinear-phase filter interference

Physical layer authentication in UAV-enabled relay networks based on manifold learning

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Science China(Information Sciences) 2022年第12期65卷 263-283页

作者： Shida XIA Xiaofeng TAO Na LI Shiji WANG Jin XU national Engineering lab for mobile Network Technologies Beijing University of Posts and Telecommunications Beijing University of Posts and Telecommun.cations research Institute

An unmanned aerial vehicle(UAV) relay network is a promising solution in the next-generation wireless networks due to its high capacity and unlimited geography. However, because of the openness of wireless channels and UAV mobility, it is remarkably challenging to guarantee the secure access of UAV relay. In this paper, we investigate the physical layer authentication(PLA) to verify the identity of the UAV relay for preventing unauthorized access to users’ information or network service. Unlike most existing PLA methods for UAV, the proposed PLA scheme fully considers the time-varying of physical layer attributes caused by UAV mobility, and transforms the authentication problem into recognizing nonlinearly separable physical layer data. Particularly, we propose a manifold learning-based PLA scheme that can authenticate the mobile UAV relay in real time by establishing the local correlation of physical layer attributes. The Markov chain of physical layer data in the time domain is established to evaluate UAV state transition probability through the proposed diffusion map algorithm. The legitimate UAV and spoofing attackers can always be authenticated by the different motion states. Performance analysis offered a comprehensive understanding of the proposed scheme. Extensive simulations confirm that the performance of the proposed scheme improves over 18% in resisting the intelligent spoofing UAV compared with the traditional methods.

关键词： UAV relay physical layer authentication mobility manifold learning diffusion map state transition probability

Polar-coded forward error correction for MLC NAND flash memory

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Science China(Information Sciences) 2018年第10期61卷 224-239页

作者： Haochuan SONG Jen-Chien FU Shih-Jia ZENG Jin SHA Zaichen ZHANG Xiaohu YOU Chuan ZHANG lab of Efficient Architectures for Digital-commun.cation(LEADS) National Mobile Communications Research Laboratory Southeast University Quantum Information Center of Southeast University national mobile commun.cations research laboratory Southeast University Lite-On Technology Corporation School of Electronic Science and Engineering Nanjing University

With the ever-growing storage density, high-speed, and low-cost data access, flash memory has inevitably become popular. Multi-level cell(MLC) NAND flash memory, which can well balance the data density and memory stability, has occupied the largest market share of flash memory. With the aggressive memory scaling, however, the reliability decays sharply owing to multiple interferences. Therefore, the control system should be embedded with a suitable error correction code(ECC) to guarantee the data integrity and accuracy. We proposed the pre-check scheme which is a multi-strategy polar code scheme to strike a balance between reasonable frame error rate(FER) and decoding latency. Three decoders namely binaryinput, quantized-soft, and pure-soft decoders are embedded in this scheme. Since the calculation of soft loglikelihood ratio(LLR) inputs needs multiple sensing operations and optional quantization boundaries, a 2-bit quantized hard-decision decoder is proposed to outperform the hard-decoded LDPC bit-flipping decoder with fewer sensing operations. We notice that polar codes have much lower computational complexity compared with LDPC codes. The stepwise maximum mutual information(SMMI) scheme is also proposed to obtain overlapped boundaries without exhausting search. The mapping scheme using Gray code is employed and proved to achieve better raw error performance compared with other alternatives. Hardware architectures are also given in this paper.

关键词： polar coding non-volatile memory error correcting code NAND flash memory

Deep Learning Based User Grouping for FD-MIMO Systems Exploiting Statistical Channel State Information

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China commun.cations 2021年第7期18卷 183-196页

作者： Shupeng Ji Qisheng Wang Shiyu Wu Jiachen Tian Xiao Li Wenjin Wang national mobile commun.cations research laboratory Southeast UniversityNanjing 210096China Pazhou lab Guangzhou 510330China

The joint spatial division and multiplexing(JSDM)is a two-phase precoding scheme for massive multiple-input-multiple-output(MIMO)system under frequency division duplex(FDD)mode to reduce the amount of channel state information(CSI)*** apply this scheme,users need to be partitioned into groups so that users in the same group have similar channel covariance eigenvectors while users in different groups have almost orthogonal *** this paper,taking the clustered user model into account,we consider the user grouping of JSDM for the downlink massive MIMO system with uniform planar antenna array(UPA)at base station(BS).A deep learning based user grouping algorithm is proposed to improve the efficiency of the user grouping *** proposed grouping algorithm transfers the statistical CSI of all users into a picture,and utilizes the deep learning enabled objective detection model you look only once(YOLO)to divide the users into different groups *** results show that the proposed user grouping scheme can achieve higher sum rate with less time delay.

关键词： deep learning objective detection YOLO user grouping massive MIMO JSDM

Native intelligence for 6G mobile network: technical challenges,architecture and key features

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The Journal of China Universities of Posts and Telecommun.cations 2022年第1期29卷 27-40页

作者： Liu Guangyi Deng Juan Zheng Qingbi Li Gang Sun Xin Huang Yuhong Future research lab China Mobile Research InstituteBeijing 100032China

The application of the artificial intelligence(AI) technology in the 5 th generation mobile commun.cation system(5 G) networks promotes the development of the mobile commun.cation network and its application in vertical industries, however, the application models of "patching" and "plug-in" have hindered the effect of AI applications. Meanwhile, the application of AI in all walks of life puts forward requirements for new capabilities of the future network, such as distributed training, real-time collaborative inference, local data processing, etc., which require "native intelligence design" in future networks. This paper discusses the requirements of native intelligence in the 6 th generation mobile commun.cation system(6 G) networks from the perspectives of 5 G intelligent network challenges and the "ubiquitous intelligence" vision of 6 G, and analyzes the technical challenges of the AI workflows in its lifecycle and the AI as a service(AIaaS) in cloud network. The progress and deficiencies of the current research on AI functional architecture in various industry organizations are summarized. The end-to-end functional architecture for native AI for 6 G network and its three key technical characteristics are proposed: quality of AI services(QoAIS) based AI service orchestration for its full lifecycle, deep integration of native AI computing and commun.cation, and integration of native AI and digital twin network. The directions of future research are also prospected.

关键词： the 5th generation mobile commun.cation system the 6th generation mobile commun.cation system artificial intelligence native intelligence network intelligence network architecture mobile commun.cation

Micro-Service-Based Radio Access Network

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China commun.cations 2022年第3期19卷 1-15页

作者： Na Li Guangyi Liu Huimin Zhang Quan Zhao Yun Zhao Zhou Tong Yingying Wang Junshuai Sun Future research lab China Mobile Research InstituteBeijing 100053China

The convergence of information,commun.cation,and data technologies(ICDT)has been identified as one of the developing trends of the sixth generation(6G)***-based architecture(SBA)as one of the promising information technology,has been preliminarily introduced into the fifth generation(5G)core network(CN)and successfully commercialized,which verifies its feasibility and ***,SBA mainly focuses on the control plane of CN at present and the SBA-CN user plane is being studied by the *** addition to further evolving the SBA-CN,SBA radio access network(RAN)should also be considered to enable an end-toend SBA,so as to meet more comprehensive and extreme requirements of future applications,as well as support fast rollout requirements of RAN devices.

关键词： 6G micro-service SBA-RAN