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Vehicular mobility patterns and their applications to Internet-of-Vehicles: a comprehensive survey

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Science China(Information Sciences) 2022年第11期65卷 5-46页

作者： qimei cui Xingxing HU Wei NI Xiaofeng TAO Ping ZHANG Tao CHEN Kwang-Cheng CHEN Martin HAENGGI School of Information and Communication Engineering Beijing University of Posts and Telecommunications Department of Broadband Communication Peng Cheng Laboratory China Mobile Research Institute Digital Productivity and Services Flagship Commonwealth Scientific and Industrial Research Organization (CSIRO) VTT Technical Research Center of Finland Department of Electrical Engineering University of South Florida Department of Electrical Engineering University of Notre Dame

With the growing popularity of the Internet-of-Vehicles(IoV), it is of pressing necessity to understand transportation traffic patterns and their impact on wireless network designs and operations. Vehicular mobility patterns and traffic models are the keys to assisting a wide range of analyses and simulations in these applications. This study surveys the status quo of vehicular mobility models, with a focus on recent advances in the last decade. To provide a comprehensive and systematic review, the study first puts forth a requirement-model-application framework in the IoV or general communication and transportation networks. Existing vehicular mobility models are categorized into vehicular distribution, vehicular traffic, and driving behavior models. Such categorization has a particular emphasis on the random patterns of vehicles in space, traffic flow models aligned to road maps, and individuals’ driving behaviors(e.g., lane-changing and car-following). The different categories of the models are applied to various application scenarios, including underlying network connectivity analysis, off-line network optimization, online network functionality, and real-time autonomous driving. Finally, several important research opportunities arise and deserve continuing research efforts, such as holistic designs of deep learning platforms which take the model parameters of vehicular mobility as input features, qualification of vehicular mobility models in terms of representativeness and completeness, and new hybrid models incorporating different categories of vehicular mobility models to improve the representativeness and completeness.

关键词： vehicular mobility pattern Internet-of-Vehicles (IoV) traffic flow spatial point process trajectory prediction machine learning deep learning

Green Concerns in Federated Learning over 6G

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China Communications 2022年第3期19卷 50-69页

作者： Borui Zhao qimei cui Shengyuan Liang Jinli Zhai Yanzhao Hou Xueqing Huang Miao Pan Xiaofeng Tao National Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and TelecommunicationsBeijing100876China Department of Computer Science New York Institute of TechnologyOld WestburyNY11568USA Department of Electrical and Computer Engineering University of HoustonHoustonTX77204USA

As Information,Communications,and Data Technology(ICDT)are deeply integrated,the research of 6G gradually ***,federated learning(FL)as a distributed artificial intelligence(AI)framework is generally believed to be the most promising solution to achieve“Native AI”in *** the adoption of energy as a metric in AI and wireless networks is emerging,most studies still focused on obtaining high levels of accuracy,with little consideration on new features of future networks and their possible impact on energy *** address this issue,this article focuses on green concerns in FL over *** first analyze and summarize major energy consumption challenges caused by technical characteristics of FL and the dynamical heterogeneity of 6G networks,and model the energy consumption in FL over 6G from aspects of computation and *** classify and summarize the basic ways to reduce energy,and present several feasible green designs for FL-based 6G network architecture from three *** to the simulation results,we provide a useful guideline to researchers that different schemes should be used to achieve the minimum energy consumption at a reasonable cost of learning accuracy for different network scenarios and service requirements in FL-based 6G network.

关键词： 6G native AI federated learning radio access network green communications

6G移动信息网络架构:从通信到一切皆服务的变迁

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中国科学：信息科学 2024年第5期54卷 1236-1266页

作者：刘光毅张慧敏佟舟李娜陈天骄华美慧刘超彭程晖艾明崔琪楣潘志文中国移动通信研究院北京100053 华为技术有限公司深圳518000 中信科移动通信技术股份有限公司北京100053 北京邮电大学信息与通信工程学院北京100053 东南大学信息科学与工程学院南京210096

5G与大数据、云计算和AI等技术的融合正在赋能千行百业的数字化转型,加速整个社会走向数字化和智慧化.面向2030年,社会发展的愿景将是“数字孪生、智慧泛在”,更加差异化和碎片化的业务场景将对移动通信网络提出全新的挑战,未来网络将... 详细信息

5G与大数据、云计算和AI等技术的融合正在赋能千行百业的数字化转型,加速整个社会走向数字化和智慧化.面向2030年,社会发展的愿景将是“数字孪生、智慧泛在”,更加差异化和碎片化的业务场景将对移动通信网络提出全新的挑战,未来网络将从提供信息传输服务,拓展到信息感知、传输、存储、处理、利用等全过程服务,实现从传统通信网络向移动信息网络的重大转变.为了高效实现这一转变,6G网络将通过通信、感知、大数据、计算、AI和安全等多领域技术的跨界融合,实现柔性、按需服务、至简、智慧内生、数字孪生和安全内生的网络设计,带来“按需服务”和“一切皆服务”的范式转变.本文从面向2030年的新应用需求、新技术趋势,以及5G网络面临的问题与挑战出发,分析6G网络发展的三大驱动力,提出6G网络架构的整体设计思路,并设计了“三层六面”6G网络逻辑功能架构和实际部署架构,打造一站式提供通信、感知、计算、AI、大数据和安全等服务的全新能力,全面提升6G网络的业务和场景适应能力,实现面向全行业、全场景、全生态的按需服务,在有效解决5G网络面临的高成本、高功耗、操作和维护难等主要问题的同时,全面赋能“数字孪生、智慧泛在”社会发展愿景的实现.

关键词： 6G 网络架构柔性至简按需服务智慧内生数字孪生安全内生

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Compressed sensing based channel estimation used in non-sample-spaced multipath channels of OFDM system

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The Journal of China Universities of Posts and Telecommunications 2015年第2期22卷 31-37页

作者： Chen Baohao cui qimei Yang Fan National Engineering Laboratory for Mobile Network Security Beijing University of Posts and Telecommunications

By virtue of an increase in spectral efficiency by reducing the transmitted pilot tones, the compressed sensing （CS） has been widely applied to pilot-aided sparse channel estimation in orthogonal frequency division multiplexing （OFDM） systems. The researches usually assume that the channel is strictly sparse and formulate the channel estimation as a standard compressed sensing problem. However, such strictly sparse assumption does not hold true in non-sample-spaced multiple channels. The authors in this article proposed a new method of compressed sensing based channel estimation in which an over-complete dictionary with a finer delay grid is applied to construct a sparse representation of the non-sample-spaced multipath channels. With the proposed, the channel estimation was formulated as the model-based CS problem and a modified model-based compressed sampling matching pursuit （CoSaMP） algorithm was applied to reconstruct the discrete-time channel impulse response （CIR）. Simulation indicates that the new method proposed here outperforms the traditional standard CS-based methods in terms of mean square error （MSE） and bit error rate （BER）.

关键词： channel estimation model-based compressed sensing non-sample-spaced multipath channels

Energy-efficient resource allocation for hybrid bursty services in multi-relay OFDM networks

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Science China(Information Sciences) 2017年第10期60卷 169-186页

作者： Yuhao ZHANG qimei cui Ning WANG Yanzhao HOU Weiliang XIE School of Information and Communication Engineering Beijing University of Posts and Telecommunications China Telecom Corporation Limited

In this paper, we propose mapped two-way water filling(MTWF) scheme to maximize energy efficiency(EE) for hybrid bursty services with quality of services(Qo S) requirements in two-way multirelay(TWMR) OFDM networks. The bursty traffic is first analyzed by strictly proved equivalent homogeneous Poisson process, based on which the Qo S requirements are converted into sum-rate constraints. The formulated non-convex EE maximization problem, including subcarrier assignment, relay selection(RS) and rate allocation, is NP-hard involving combinatorial optimization. To conduct optimal RS on each subcarrier without priori bursty traffic knowledge, we utilize some approximate relationships under high data rate demands to remove its dependence on two-way data rates, and simplify the whole optimization problem as well. After the optimal channel configuration is obtained, which only depends on channel conditions, subcarrier assignment is attained through elitist selection genetic algorithm(ESGA), and rate allocation of each service is fulfilled by deducing two-way water filling principle. A new equivalent optimization objective function is proposed next as the simple evaluating index in ESGA to reduce complexity. Finally, simulations are carried out to verify the superiority and convergence of our scheme, as well as the applicability for different scenarios.

关键词： energy efficiency resource allocation hybrid bursty services two-way multi-relay genetic algorithm

Compressive Sensing Based Wireless Localization in Indoor Scenarios

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China Communications 2012年第4期9卷 1-12页

作者： cui qimei Deng Jingang Zhang Xuefei Key Laboratory of Universal Wireless Communications Beijing University of Posts and Telecommunications Ministry ofEducation Beijing 100876 P. R. China

The sparse nature of location finding in the spatial domain makes it possible to exploit the Compressive Sensing (CS) theory for wireless ***-based location algorithm can largely reduce the number of online measurements while achieving a high level of localization accuracy,which makes the CS-based solution very attractive for indoor ***,CS theory offers exact deterministic recovery of the sparse or compressible signals under two basic restriction conditions of sparsity and *** order to achieve a good recovery performance of sparse signals,CS-based solution needs to construct an efficient CS *** model must satisfy the practical application requirements as well as following theoretical *** this paper,we propose two novel CS-based location solutions based on two different points of view:the CS-based algorithm with raising-dimension pre-processing and the CS-based algorithm with Minor Component Analysis (MCA).Analytical studies and simulations indicate that the proposed novel schemes achieve much higher localization accuracy.

关键词：无线定位可压缩室内场景 CS理论传感定位精度 CS算法稀疏性

Energy-aware deployment of dense heterogeneous cellular networks with QoS constraints

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Science China(Information Sciences) 2017年第4期60卷 148-165页

作者： qimei cui Zhiyan cui Wei ZHENG Riku JNTTI Weiliang XIE National Engineering Laboratory for Mobile Network Security Beijing University of Posts and Telecommunications Department of Communications and Networking Aalto University China Telecom Corporation Limited

The base station(BS) configuration is a key factor to improve energy efficiency(EE). In this paper,we focus on designing the network deployment parameters(i.e., BS densities) for biased K-tier heterogeneous cellular network(HCN) with quality of service(Qo S) provisioning. Using appropriate approximations, we derive the closed-form expressions of optimal BS density across all tiers to minimize the area power consumption(APC) by applying the stochastic geometry theory, while satisfying the users’ Qo S requirements. These results are used to obtain some new insights into the EE performance of biased HCN deployment. With the aid of this approach, the best type of BSs to be deployed or switched off for energy saving purposes can be identified from the perspectives of BS transmission power. More precisely, if the BS transmission power ratio between an arbitrary pair of tiers of K-tier HCN, e.g., the small cell BS and macro BS tiers, is higher than a threshold which is a function of path loss exponent, bias factor and power consumption, the small cell BSs are *** opposite situation takes place otherwise. Furthermore, it is also shown that, compared to the unbiased HCN scenario, significant energy savings are possible by appropriately biasing the HCN and optimizing the BS density, subject to the Qo S constraints among all tiers.

关键词： heterogeneous cellular networks stochastic geometry energy efficiency BS density energy saving

Multi-pair massive MIMO amplify-and-forward relaying system with low-resolution ADCs:performance analysis and power control

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Science China(Information Sciences) 2018年第2期61卷 164-181页

作者： qimei cui Yinjun LIU Yinsheng LIU Weiliang XIE Yong ZHAO National Engineering Laboratory for Mobile Network Security Beijing University of Posts and Telecommunications State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University China Telecom Corporation Limited

In this paper, we focus on a general multi-pair massive MIMO amplify-and-forward(AF) relaying system where the relay antennas employ low-resolution analog-to-digital converters(ADCs) to reduce the hardware cost. First, considering the effect of low quantization on channel estimation, a tight closed form approximation of the system ergodic achievable rate is derived. Second, some asymptotic analysis is presented to reveal the impacts of the system parameters on the achievable rate. Particularly, the generalized power scaling schemes are characterized. The results indicate that in some cases, when the number of relay antennas grows without bound, the impact of the finite resolution ADCs on data transmission can be eliminated. To enhance the achievable rate of the quantized systems, the optimal user and relay power control schemes are proposed. Furthermore, to reap all the benefits of low-resolution ADCs, another power control scheme is also designed to minimize the total power consumption while guaranteeing the quality-of-service(Qo S)requirement of each user, which can help draw some useful insights into the optimal ADC resolution from power saving perspectives. The simulation results confirm the accuracy of our theoretical analysis and the effectiveness of the proposed power control schemes.

关键词： massive MIMO relaying system imperfect CSI low quantization power control

Stochastic geometry based analysis for heterogeneous networks: a perspective on meta distribution

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Science China(Information Sciences) 2020年第12期63卷 230-250页

作者： Xinlei YU qimei cui Yuanjie WANG Na LI Xiaofeng TAO Mikko VALKAMA National Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and Telecommunications National Computer Network Emergency Response Technical Team/Coordination Center of China (CNCERT/CC) Department of Electrical Engineering Tampere University

The meta distribution as a new performance metric can provide much more fine-grained information about the individual link reliability, and is of great value for the analysis and design of the future cellular networks. In this paper, we investigate the stochastic geometry based analysis for heterogeneous networks from the perspective on the meta distribution. The comprehensive overview for the fundamental framework of the meta distribution is provided, which involves the concepts of the meta distribution and its related performance metric(e.g., mean local delay and spatial outage capacity) and the efficient calculation methods of the meta distribution. The insights of the meta distribution are also stated by the comparison with standard success probability. The various applications of the meta distribution to heterogeneous networks are summarized and categorized by different types of technologies. Furthermore, some open issues and future work are discussed to promote the development and application of the meta distribution.

关键词： meta distribution stochastic geometry heterogeneous network success probability per-link reliability