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Recent Developments in Authentication Schemes Used in Machine-Type Communication Devices in Machine-to-Machine Communication: Issues and Challenges
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作者 Shafi Ullah Sibghat Ullah Bazai +9 位作者 Mohammad Imran Qazi Mudassar Ilyas Abid Mehmood Muhammad Asim Saleem Muhmmad Aasim Rafique Arsalan Haider Ilyas Khan Sajid Iqbal Yonis Gulzar Kauser Hameed 《Computers, Materials & Continua》 SCIE EI 2024年第4期93-115,共23页
Machine-to-machine (M2M) communication plays a fundamental role in autonomous IoT (Internet of Things)-based infrastructure, a vital part of the fourth industrial revolution. Machine-type communication devices(MTCDs) ... Machine-to-machine (M2M) communication plays a fundamental role in autonomous IoT (Internet of Things)-based infrastructure, a vital part of the fourth industrial revolution. Machine-type communication devices(MTCDs) regularly share extensive data without human intervention while making all types of decisions. Thesedecisions may involve controlling sensitive ventilation systems maintaining uniform temperature, live heartbeatmonitoring, and several different alert systems. Many of these devices simultaneously share data to form anautomated system. The data shared between machine-type communication devices (MTCDs) is prone to risk dueto limited computational power, internal memory, and energy capacity. Therefore, securing the data and devicesbecomes challenging due to factors such as dynamic operational environments, remoteness, harsh conditions,and areas where human physical access is difficult. One of the crucial parts of securing MTCDs and data isauthentication, where each devicemust be verified before data transmission. SeveralM2Mauthentication schemeshave been proposed in the literature, however, the literature lacks a comprehensive overview of current M2Mauthentication techniques and the challenges associated with them. To utilize a suitable authentication schemefor specific scenarios, it is important to understand the challenges associated with it. Therefore, this article fillsthis gap by reviewing the state-of-the-art research on authentication schemes in MTCDs specifically concerningapplication categories, security provisions, and performance efficiency. 展开更多
关键词 AUTHENTICATION cyber security internet of things machine-type communication devices machine-to-machine communication
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Massive Unsourced Random Access Under Carrier Frequency Offset
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作者 XIE Xinyu WU Yongpeng +1 位作者 YUAN Zhifeng MA Yihua 《ZTE Communications》 2023年第3期45-53,共9页
Unsourced random access(URA)is a new perspective of massive access which aims at supporting numerous machine-type users.With the appearance of carrier frequency offset(CFO),joint activity detection and channel estimat... Unsourced random access(URA)is a new perspective of massive access which aims at supporting numerous machine-type users.With the appearance of carrier frequency offset(CFO),joint activity detection and channel estimation,which is vital for multiple-input and multiple-output URA,is a challenging task.To handle the phase corruption of channel measurements under CFO,a novel compressed sensing algorithm is proposed,leveraging the parametric bilinear generalized approximate message passing framework with a Markov chain support model that captures the block sparsity structure of the considered angular domain channel.An uncoupled transmission scheme is proposed to reduce system complexity,where slot-emitted messages are reorganized relying on clustering unique user channels.Simulation results reveal that the proposed transmission design for URA under CFO outperforms other potential methods. 展开更多
关键词 activity detection channel estimation frequency offset massive machine-type communication massive MIMO
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Data Aggregation-based Transmission Method in Ultra-Dense Wireless Networks
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作者 Dae-Young Kim Seokhoon Kim 《Intelligent Automation & Soft Computing》 SCIE 2023年第1期727-737,共11页
As the Internet of Things(IoT)advances,machine-type devices are densely deployed and massive networks such as ultra-dense networks(UDNs)are formed.Various devices attend to the network to transmit data using machine-t... As the Internet of Things(IoT)advances,machine-type devices are densely deployed and massive networks such as ultra-dense networks(UDNs)are formed.Various devices attend to the network to transmit data using machine-type communication(MTC),whereby numerous,various are generated.MTC devices generally have resource constraints and use wireless communication.In this kind of network,data aggregation is a key function to provide transmission efficiency.It can reduce the number of transmitted data in the network,and this leads to energy saving and reducing transmission delays.In order to effectively operate data aggregation in UDNs,it is important to select an aggregation point well.The total number of transmitted data may vary,depending on the aggregation point to which the data are delivered.Therefore,in this paper,we propose a novel data aggregation scheme to select the appropriate aggregation point and describe the data transmission method applying the proposed aggregation scheme.In addition,we evaluate the proposed scheme with extensive computer simulations.Better performances in the proposed scheme are achieved compared to the conventional approach. 展开更多
关键词 Data aggregation data transmission ultra-dense network machine-type communication Internet of Things
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Contention-Based Nonorthogonal Massive Access with Massive MIMO 被引量:3
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作者 Yanna Bai Wei Chen +1 位作者 Bo Ai Zhangdui Zhong 《China Communications》 SCIE CSCD 2020年第11期79-90,共12页
The sporadic communication character of massive machine-type communication systems provides natural advantages to utilize the principle of compressive sensing(CS).However,due to the high computational complexity of CS... The sporadic communication character of massive machine-type communication systems provides natural advantages to utilize the principle of compressive sensing(CS).However,due to the high computational complexity of CS algorithms,CS-based contention-free access schemes have limited scalability and high computational complexity for massive access with user-specific pilots.To address these problems,in this paper,we propose a new contention-based scheme for CSbased massive access,which can support the sporadic access of massive devices(more than one million devices)with limited resources.Furthermore,an advanced receiver algorithm is designed to solve the optimal solutions for the proposed scheme,which utilizes various prior information to enhance the performance.In specific,the joint sparsity between the channel and data is used to improve the accuracy of pilot detection,and the information of modulation and cyclic redundancy check is exploited for channel correction to improve the performance of data recovery.The simulation results show that the proposed scheme can achieve improved active user detection performance and data recovery accuracy than existing methods. 展开更多
关键词 massive machine-type communication nonorthogonal access compressive sensing contention based access
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Energy-Efficient MTC Data Offloading in Wireless Networks Based on K-Means Grouping Technique
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作者 Juma Saidi Ally Muhammad Asif Qingli Ma 《Journal of Computer and Communications》 2019年第2期47-61,共15页
Machine-type communication (MTC) devices provide a broad range of data collection especially on the massive data generated environments such as urban, industrials and event-enabled areas. In dense deployments, the dat... Machine-type communication (MTC) devices provide a broad range of data collection especially on the massive data generated environments such as urban, industrials and event-enabled areas. In dense deployments, the data collected at the closest locations between the MTC devices are spatially correlated. In this paper, we propose a k-means grouping technique to combine all MTC devices based on spatially correlated. The MTC devices collect the data on the event-based area and then transmit to the centralized aggregator for processing and computing. With the limitation of computational resources at the centralized aggregator, some grouped MTC devices data offloaded to the nearby base station collocated with the mobile edge-computing server. As a sensing capability adopted on MTC devices, we use a power exponential function model to compute a correlation coefficient existing between the MTC devices. Based on this framework, we compare the energy consumption when all data processed locally at centralized aggregator or offloaded at mobile edge computing server with optimal solution obtained by the brute force method. Then, the simulation results revealed that the proposed k-means grouping technique reduce the energy consumption at centralized aggregator while satisfying the required completion time. 展开更多
关键词 machine-type Communication Correlation DATA OFFLOADING GROUPING TECHNIQUE Differential Entropy Power EXPONENTIAL Function
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Deployment of Polar Codes for Mission-Critical Machine-Type Communication Over Wireless Networks
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作者 Najib Ahmed Mohammed Ali Mohammed Mansoor +1 位作者 Rodina Binti Ahmad Saaidal Razalli Bin Azzuhri 《Computers, Materials & Continua》 SCIE EI 2022年第4期573-592,共20页
Mission critical Machine-type Communication(mcMTC),also referred to as Ultra-reliable Low Latency Communication(URLLC),has become a research hotspot.It is primarily characterized by communication that provides ultra-h... Mission critical Machine-type Communication(mcMTC),also referred to as Ultra-reliable Low Latency Communication(URLLC),has become a research hotspot.It is primarily characterized by communication that provides ultra-high reliability and very low latency to concurrently transmit short commands to a massive number of connected devices.While the reduction in physical(PHY)layer overhead and improvement in channel coding techniques are pivotal in reducing latency and improving reliability,the current wireless standards dedicated to support mcMTC rely heavily on adopting the bottom layers of general-purpose wireless standards and customizing only the upper layers.The mcMTC has a significant technical impact on the design of all layers of the communication protocol stack.In this paper,an innovative bottom-up approach has been proposed for mcMTC applications through PHY layer targeted at improving the transmission reliability by implementing ultra-reliable channel coding scheme in the PHY layer of IEEE 802.11a standard bearing in mind short packet transmission system.To achieve this aim,we analyzed and compared the channel coding performance of convolutional codes(CCs),low-density parity-check(LDPC)codes,and polar codes in wireless network on the condition of short data packet transmission.The Viterbi decoding algorithm(VA),logarithmic belief propagation(Log-BP)algorithm,and cyclic redundancy check(CRC)successive cancellation list(SCL)(CRC-SCL)decoding algorithm were adopted to CC,LDPC codes,and polar codes,respectively.Consequently,a new PHY layer for mcMTC has been proposed.The reliability of the proposed approach has been validated by simulation in terms of Bit error rate(BER)and packet error rate(PER)vs.signal-to-noise ratio(SNR).The simulation results demonstrate that the reliability of IEEE 802.11a standard has been significantly improved to be at PER=10−5 or even better with the implementation of polar codes.The results also show that the general-purpose wireless networks are prominent inproviding short packet m 展开更多
关键词 machine-type communication mission-critical applications MTC URLLC M2M wireless networks polar codes
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Reconfigurable intelligent surface assisted grant-free massive access
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作者 Xingyu Zhou Keke Ying +3 位作者 Shicong Liu Malong Ke Zhen Gao Mohamed-Slim Alouini 《Intelligent and Converged Networks》 EI 2022年第1期134-143,共10页
Massive machine-type communications(mMTC)is envisioned to be one of the pivotal scenarios in the fifth-generation(5G)wireless communication,where the explosively emerging Internet-of-Things(IoT)applications have trigg... Massive machine-type communications(mMTC)is envisioned to be one of the pivotal scenarios in the fifth-generation(5G)wireless communication,where the explosively emerging Internet-of-Things(IoT)applications have triggered the demand for services with low-latency and high-reliability.To this end,grant-free random access paradigm has been proposed as a promising enabler in simplifying the connection procedure and significantly reducing access latency.In this paper,we propose to leverage the burgeoning reconfigurable intelligent surface(RIS)for grant-free massive access working at millimeter-wave(mmWave)frequency to further boost access reliability.By attaching independently controllable phase shifts,reconfiguring,and refracting the propagation of incident electromagnetic waves,the deployed RISs could provide additional diversity gain and enhance the access channel conditions.On this basis,to address the challenging active device detection(ADD)and channel estimation(CE)problem,we develop a joint-ADDCE(JADDCE)method by resorting to the existing approximate message passing(AMP)algorithm with expectation maximization(EM)to extract the structured common sparsity in traffic behaviors and cascaded channel matrices.Finally,simulations are carried out to demonstrate the superiority of our proposed scheme. 展开更多
关键词 reconfigurable intelligent surface(RIS) massive machine-type communications(mMTC) grant-free random access(GF-RA) active device detection channel estimation approximate message passing(AMP)
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Scheduling Scheme for Cellular-Based Machine-Type Communication 被引量:1
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作者 李红艳 杜白 +1 位作者 索龙 李建东 《China Communications》 SCIE CSCD 2011年第1期145-150,共6页
Cellular-based Machine-Type Communication (MTC) will become more and more important in the near future for the advantage of the long-distance wireless communication.However,a large number of MTC applications introduce... Cellular-based Machine-Type Communication (MTC) will become more and more important in the near future for the advantage of the long-distance wireless communication.However,a large number of MTC applications introduce heavy load to cellular network.MTC traffic scheduling schemes are proposed to avoid congestion in this paper.Our approaches are based on the delay-tolerance of MTC traffic.Some MTC traffic is postponed until the network load becomes light.Moreover,our scheme efficiently utilizes the bandwidth resources reserved for handover in traditional cellular network.Simulation results show that the utility usage of radio resources is improved and the congestion probability is reduced. 展开更多
关键词 machine-type Communication traffic scheduling congestion avoidance
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Enhanced Power Choice Barring Scheme For Massive MTCs With Grant-Free NOMA 被引量:1
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作者 Liang Wu Xiaorui Tang +1 位作者 Zaichen Zhang Jian Dang 《China Communications》 SCIE CSCD 2021年第10期135-147,共13页
Massive machine-type communication(m MTC)is a typical application scenario of the fifth generation(5G)mobile communications.To keep the m MTC reliable and minimize the energy consumption of the m MTC devices,this pape... Massive machine-type communication(m MTC)is a typical application scenario of the fifth generation(5G)mobile communications.To keep the m MTC reliable and minimize the energy consumption of the m MTC devices,this paper proposes an enhanced power choice barring(EPCB)scheme based on the distributed layered grant-free non-orthogonal multiple access(NOMA)framework,where the cell is divided into different layers according to a predetermined power levels.The proposed EPCB scheme not only combines the grant-free strategy with the sleep mode to reduce the energy consumption,but also designs a power level choosing strategy to increase the access success probability.Simulation results show that when compared with existing schemes,the proposed EPCB scheme has better performance in the aspects of the access success probability and energy efficiency. 展开更多
关键词 grant-free massive machine-type communication NOMA power level choosing
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3GPP 5G NR物理层关键技术综述 被引量:18
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作者 黄陈横 《移动通信》 2018年第10期1-8,共8页
第五代(5G)移动通信技术被称为新型无线空口,主要满足三大应用场景的通信需求,即增强型移动宽带(eMBB)、超可靠低时延通信(uRLLC)以及海量机器通信(mMTC)。其使用的关键技术包括超精简传输、低时延设计、大规模MIMO以及高低频范围内灵... 第五代(5G)移动通信技术被称为新型无线空口,主要满足三大应用场景的通信需求,即增强型移动宽带(eMBB)、超可靠低时延通信(uRLLC)以及海量机器通信(mMTC)。其使用的关键技术包括超精简传输、低时延设计、大规模MIMO以及高低频范围内灵活的频谱使用方式等。根据3GPP TS 38系列的最新技术规范,重点介绍了5G NR层1的关键技术,侧重于与4G LTE的比较,并通过描述5G NR的基本概念,详细解释物理信道和参考信号的设计原理,分享当前5G标准化的最新成果。 展开更多
关键词 新型无线空口 增强型移动宽带 超可靠低时延通信 海量机器通信 物理层
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基于虚拟样机的桁架式喷洒车稳定性动力学仿真 被引量:14
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作者 汤跃 赵进 +1 位作者 邱志鹏 彭涛 《农业机械学报》 EI CAS CSCD 北大核心 2015年第7期72-78,共7页
为了提高卷盘式喷灌机桁架式喷洒车爬坡和抗倾覆能力,克服喷洒车试验周期长、成本高、试验优化能力受限制的缺点,采用虚拟样机软件ADAMS建立JP75型喷灌机桁架式喷洒车的动力学参数化仿真模型,对喷洒车的纵向、横向抗倾覆性以及爬坡能力... 为了提高卷盘式喷灌机桁架式喷洒车爬坡和抗倾覆能力,克服喷洒车试验周期长、成本高、试验优化能力受限制的缺点,采用虚拟样机软件ADAMS建立JP75型喷灌机桁架式喷洒车的动力学参数化仿真模型,对喷洒车的纵向、横向抗倾覆性以及爬坡能力进行了仿真。分析了不同坡度角工况下影响桁架式喷洒车爬坡和抗倾覆能力的几种关键因素,采用二分法控制仿真坡度角的变化,对各因素的影响程度进行了仿真试验研究,提高了仿真速度。通过对影响爬坡和倾覆性能较大的地面粘附系数、质心高度、轮距等关键因素进行优化,使临界爬坡角比现有喷洒车提高了21.48%。优化后新机型的试验运行结果表明,在同样坡度工况下新机型倾覆次数明显减少,能够达到的最大爬坡角得到提高,仿真优化取得明显效果。 展开更多
关键词 卷盘式喷灌机 桁架式喷洒车 动力学仿真 车辆地面力学
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面向6G的智能机器通信与网络 被引量:8
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作者 陈旭 尉志青 +1 位作者 冯志勇 潘淼 《物联网学报》 2020年第1期59-71,共13页
随着智慧城市、智能制造等产业的快速发展,机器类通信得到学术界和产业界的广泛关注。机器类通信网络的功能集成化、智能化程度越来越高,对网络的时延、可靠性、连接设备数、峰值速率、安全性和可扩展性等指标提出了更严苛的要求。总结... 随着智慧城市、智能制造等产业的快速发展,机器类通信得到学术界和产业界的广泛关注。机器类通信网络的功能集成化、智能化程度越来越高,对网络的时延、可靠性、连接设备数、峰值速率、安全性和可扩展性等指标提出了更严苛的要求。总结分析了4G、5G至未来6G时代的机器类通信网络需求的变化以及相应网络架构与关键技术的演化,在此基础上提出了面向6G机器类通信网络的感传算一体化智能机器通信网络架构。 展开更多
关键词 机器类通信 智能通信网络 感传算一体化
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机夹型叶根铣刀设计及自动检测技术
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作者 徐燕 杨林建 周乐安 《工具技术》 北大核心 2024年第7期157-160,共4页
分析机夹型叶根精铣刀的设计方法,确定刀具刃口型线,通过UG建立刀体模型并进行加工程序模拟,通过NUMROTO软件进行3D模拟,查看模型是否与型线外形符合,测量和优化刀具角度,在无碰撞和干涉条件下对刀槽进行加工和测量。确定刀片装配位置... 分析机夹型叶根精铣刀的设计方法,确定刀具刃口型线,通过UG建立刀体模型并进行加工程序模拟,通过NUMROTO软件进行3D模拟,查看模型是否与型线外形符合,测量和优化刀具角度,在无碰撞和干涉条件下对刀槽进行加工和测量。确定刀片装配位置、设计槽型的加工顺序,建立合适的刀具坐标系,采用CadLoadModel语句导入理论模型后进行元素分组,实现机器坐标系与模型坐标系的统一,检测表明,该设计方案满足使用要求,提高了叶片加工效率。该工艺对其他机夹型叶根铣刀的研究具有一定推广使用价值。 展开更多
关键词 机夹型 精铣刀 结构设计 刀具角度 自动检测
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串行干扰消除接收机下模式分割随机接入设计与分析
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作者 庞立卓 闵洁 +4 位作者 李佳慧 李倩倩 郝诗雅 李林涛 戴晓明 《移动通信》 2024年第5期69-73,共5页
利用模式域导频进行信道估计的PDRA框架可有效减轻机器类通信MTC背景下RA的导频碰撞问题。为进一步探索PDRA框架的潜能,将串行干扰消除SIC接收机与PDRA结合,利用SIC算法消除解码成功用户的模式域导频信号来降低干扰,从而缓解导频碰撞问... 利用模式域导频进行信道估计的PDRA框架可有效减轻机器类通信MTC背景下RA的导频碰撞问题。为进一步探索PDRA框架的潜能,将串行干扰消除SIC接收机与PDRA结合,利用SIC算法消除解码成功用户的模式域导频信号来降低干扰,从而缓解导频碰撞问题。仿真结果表明,与MF接收机下的PDRA方案相比,SIC接收机能进一步利用PDRA框架带来的潜在增益,呈现出更高的接入成功概率。 展开更多
关键词 机器类通信 随机接入 导频碰撞 模式分割随机接入 串行干扰消除
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LTE演进背景下的M2M通信适配技术 被引量:4
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作者 王艺 《电信科学》 北大核心 2014年第11期44-49,共6页
M2M技术是智慧城市的关键技术之一。M2M的通信特征和业务特征对LTE演进背景下的通信运营商移动网络系统提出了新的要求。针对M2M通信特征,描述了运营商移动网络的改进进展、改进思路和网络演进的3个阶段。针对M2M业务特征,描述了3GPP的... M2M技术是智慧城市的关键技术之一。M2M的通信特征和业务特征对LTE演进背景下的通信运营商移动网络系统提出了新的要求。针对M2M通信特征,描述了运营商移动网络的改进进展、改进思路和网络演进的3个阶段。针对M2M业务特征,描述了3GPP的SCS体系、可管理M2M通道以及通过OTA进行运营商切换的GSMA eSIM体系。 展开更多
关键词 M2M 机器类型通信 业务能力服务器 eSIM OTA 注册管理-数据准备 注册管理-安全路由
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基于证据理论的产品选型决策方法 被引量:3
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作者 李玲玲 刘锋国 +1 位作者 郭素娜 高朝晖 《工程设计学报》 CSCD 北大核心 2006年第5期281-285,共5页
基于模糊数学原理和证据理论,提出了综合处理不确定性设计信息、合理选择产品机械结构类型的方法.为此,首先利用已有的产品实例为每个产品子类提取一组设计规则,并为每个子类构造一个可以描述其典型特征的模糊向量;然后在模糊机制下统... 基于模糊数学原理和证据理论,提出了综合处理不确定性设计信息、合理选择产品机械结构类型的方法.为此,首先利用已有的产品实例为每个产品子类提取一组设计规则,并为每个子类构造一个可以描述其典型特征的模糊向量;然后在模糊机制下统一处理以普通实数、实数域上的区间值和模糊数表达的设计信息,采用模糊推理、证据理论等不精确推理方法处理不确定性信息,确定产品类型.上述方法可作为智能设计系统求解设计问题的推理策略,并实现知识的自动获取.通过一个选型设计的实例,验证了该方法的正确性. 展开更多
关键词 产品机械结构选型 证据理论 小确定性信息 不精确推理
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基于稀疏感知有序干扰消除的大规模机器类通信系统多用户检测 被引量:5
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作者 申滨 吴和彪 +1 位作者 赵书锋 崔太平 《电子与信息学报》 EI CSCD 北大核心 2020年第12期2960-2968,共9页
在大规模机器类通信(mMTC)系统中,以用户活跃性为先验信息,接收机可以基于稀疏感知最大后验概率(S-MAP)准则来检测多用户信号。为了降低S-MAP检测的计算复杂度,基于干扰消除的思想,该文提出一种改进的活跃性感知有序正交三角分解(IA-SQ... 在大规模机器类通信(mMTC)系统中,以用户活跃性为先验信息,接收机可以基于稀疏感知最大后验概率(S-MAP)准则来检测多用户信号。为了降低S-MAP检测的计算复杂度,基于干扰消除的思想,该文提出一种改进的活跃性感知有序正交三角分解(IA-SQRD)算法,以适用于mMTC系统上行链路多用户信号检测。IA-SQRD算法将传统的活跃性感知有序正交三角分解(A-SQRD)算法的最终解作为初始解,并额外增加迭代干扰消除操作,以进一步提高检测性能。此外,利用与改进A-SQRD算法相似的思路,该文对稀疏感知串行干扰消除(SA-SIC)、有序正交三角分解(SQRD)及数据相关的排序和正则化(DDS)算法亦进行了改进设计,分别获得了相应的改进型算法,即ISA-SIC、I-SQRD及I-DDS算法。仿真结果表明:相对于A-SQRD算法,在未显著增加计算复杂度的情况下,在系统误比特率(BER)为2.5×10^-2时,该文所提IA-SQRD算法可取得3 dB性能增益;并且,对于不同的活跃概率或扩频序列长度等参数配置下的mMTC系统,IA-SQRD算法相对于其它算法均表现出更优良的多用户检测性能。 展开更多
关键词 多用户检测 大规模机器类通信 最大后验概率 串行干扰消除
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一种MTC快速上行授权接入改进算法
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作者 陈发堂 杨夏 韩才君 《系统工程与电子技术》 EI CSCD 北大核心 2023年第12期4064-4072,共9页
快速上行授权接入是大规模机器类通信的关键技术之一,而缓解上行共享信道资源紧张并针对时延和速率等服务质量(quality of services,QoS)高效地进行调度是对其进行优化的重要方向。针对这一问题,提出一种应用多臂赌博机(multi-armed ban... 快速上行授权接入是大规模机器类通信的关键技术之一,而缓解上行共享信道资源紧张并针对时延和速率等服务质量(quality of services,QoS)高效地进行调度是对其进行优化的重要方向。针对这一问题,提出一种应用多臂赌博机(multi-armed bandit,MAB)学习和功率域非正交多址接入(power-domain non-orthogonal multiple access,PD-NOMA)技术的快速上行授权接入算法。所提算法通过多路MAB筛选高接入速率、低接入忍耐时延要求和低接入速率、低接入忍耐时延要求的两类设备,允许其优先被调度并复用上行资源进行接入。仿真结果表明,算法降低了系统的上行资源浪费率,在提高了接入能力的同时减少了因非正交多址接入(non-orthogonal multiple access,NOMA)造成速率损失带来的影响,并优化了系统QoS。 展开更多
关键词 机器类通信 快速上行授权 多臂赌博机 非正交多址接入
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低精度ADC下大规模机器类通信中的低复杂度信号检测算法
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作者 蒲旭敏 杨小珑 陈前斌 《重庆邮电大学学报(自然科学版)》 CSCD 北大核心 2023年第2期263-272,共10页
免授权大规模机器类通信(massive machine-type communication,mMTC)系统上行链路面临低分辨率量化、相关衰落信道以及机器类设备(machine-type device,MTD)活跃概率未知等实际挑战。针对上述问题,引入广义期望一致性(generalized expec... 免授权大规模机器类通信(massive machine-type communication,mMTC)系统上行链路面临低分辨率量化、相关衰落信道以及机器类设备(machine-type device,MTD)活跃概率未知等实际挑战。针对上述问题,引入广义期望一致性(generalized expectation consistent,GEC)算法,然而GEC算法涉及高维矩阵求逆,其复杂度高达O(N 3),其中N为MTD数量。结合Woodbury公式与诺曼级数近似,并利用发射数据帧的结构稀疏性,提出了一种基于多测量矢量的近似广义期望一致性(approximate generalized expectation consistent multiple measurement vector,AGEC-MMV)算法,在mMTC系统中(基站天线数量M<N),该算法能够规避GEC中的高维矩阵求逆,使其复杂度由O(N 3)降至O(N 2M)。仿真结果表明,所提AGEC-MMV算法能以较低复杂度取得接近GEC算法的性能,且在鲁棒性方面优于现有先进算法。 展开更多
关键词 大规模机器类通信 低复杂度 低分辨率量化 多测量矢量
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机械压接式电容器套管的研制 被引量:3
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作者 郭天兴 张波 +1 位作者 谭艺玲 张爱莉 《电力电容器与无功补偿》 2008年第2期19-21,32,共4页
主要介绍了电容器用机械压接式套管的基本结构和特点。并就该新型套管的基本性能如机械强度性能、密封性能、电气强度、耐过电流性能以及密封垫圈的相溶性进行了深入的分析与研究。同时提出了相关的试验检验方法及限值。
关键词 新型 机械滚压式 电容器套管
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