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A Joint Activity and Data Detection Scheme for Asynchronous Grant-Free Rateless Multiple Access

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China Communications 2024年第1期21卷 34-52页

作者： Wei Zhang xiaofeng zhong Shidong Zhou Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

This paper considers the frameasynchronous grant-free rateless multiple access(FAGF-RMA)scenario,where users can initiate access at any symbol time,using shared channel resources to transmit data to the base *** coding is introduced to enhance the reliability of the *** literature has shown that FA-GFRMA can achieve lower access delay than framesynchronous grant-free rateless multiple access(FSGF-RMA),with extreme reliability enabled by rateless *** support FA-GF-RMA in more practical scenarios,a joint activity and data detection(JADD)scheme is *** the feature of sporadic traffic,approximate message passing(AMP)is exploited for transmission signal matrix ***,to determine the packet start points,a maximum posterior probability(MAP)estimation problem is solved based on the recovered transmitted signals,leveraging the intrinsic power pattern in the *** iterative power-pattern-aided AMP algorithm is devised to enhance the estimation performance of *** results verify that the proposed solution achieves a delay performance that is comparable to the performance limit of FA-GF-RMA.

关键词： asynchronous grant-free JADD rateless codes

A Numerical Modeling of the Vortex-induced Vibration of Cascade in Turbomachinery using Immersed Boundary Method

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Journal of Thermal Science 2011年第3期20卷 229-237页

作者： Guotun Hu Lin Du Guohua zhong xiaofeng Sun School of Jet Propulsion Beihang University Beijing 100191 China

Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate *** numerical method is applied to the simulation of the flow passing an oscillating circular cylinder which is forced to move in X direction under prescribed motions in water at rest at low Keulegan-Carpenter *** vor-tex-induced vibration of a cylinder with two degrees of freedom which oscillates in in-line direction and transverse direction is simulated using this *** results are in good agreement with the previous *** the method is extended to the oscillating cascade simulation of making various *** is found that the IBPA(inter blade phase angle) will change as the time goes on,because of the non-uniformity of the flow in the circumferential direction,until the oscillating cascade goes to a stable *** reduced velocity and the number of blades are chosen to investigate the effects of them on *** results indicate that both the reduced velocity and the number of blades are the main factors which influence *** is worth noting that the coupling process is not necessary to generate any body-fitting grids,which makes it much faster in computational process for such a complicated fluid-structure interaction problem.

关键词： turbomachinery IB method vortex-induced vibration oscillating cascade

A Genetic Pathway for Tapetum Development and Function in Arabidopsis

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Journal of Integrative Plant Biology 2011年第11期53卷 892-900页

作者： Jun Zhu Yue Lou xiaofeng Xu zhong-Nan Yang College of Life and Environmental Sciences Shanghai Normal University Shanghai 200234 China

In anther development, tapetal cells take part in complex processes, including endomitosis and apoptosis （programmed cell death）. The tapetum provides many of the proteins, lipids, polysaccharides and other molecules necessary for pollen development. Several transcription factors, including DYT1, TDF1, AMS, MS188 and MS1, have been reported to be essential for tapetum development and function in Arabidopsis thaliana. Here, we present a detailed cytological analysis of knockout mutants for these genes, along with an in situ RNA hybridization experiment and double mutant analysis showing that these transcription factors form a genetic pathway in tapetum development. DYT1, TDF1 and AMS function in early tapetum development, while MS188 and MS1 are important for late tapetum development. The genetic pathway revealed in this work facilitates further investigation of the function and molecular mechanisms of tapetum development in Arabidopsis.

关键词： anther development genetic pathway pollen development tapetum transcription factor DYT1 TDF1 AMS MS188 MS1.

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GUEST EDITORIAL

China Communications 2022年第3期19卷 129-131页

作者： Depeng Jin Xiaoming Tao xiaofeng zhong Jintao Wang Department of Electronic Engineering Tsinghua University Department Council Electronic Engineering Dept. Tsinghua Univ Department of Electronic Engineering at Tsinghua University Department of Electronic Engineering at Tsinghua University

AI-Empowered Future Communication Networks Recently, the fifth-generation(5G) of wireless network has been developed to support enhanced mobile broadband(eMBB), massive machine-type communications(mMTC) and ultra-reliable and low-latency communications(uRLLC). However, with the tremendous increase of data services,

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On opportunistic spectrum efficiency in cognitive radio systems

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High Technology Letters 2009年第2期15卷 170-174页

作者：王鹏 zhong xiaofeng Xiao Limin Zhou Shidong Wang Jing Bai Yong State Key Laboratory on Microwave and Digital Communications Tsinghna National Laboratory for Information Science and Technology Department of Electronic Engineering Tsinghua University Beijing 100084 P.R. China DoCoMo Beijing Communications Laboratories Compary Limited Beijing 100080 P.R. China

The performance bound of cognitive radio systems is *** use opportunistic spectrum effi-ciency(OSE)as the performance metric,and point out that the maximum achievable OSE can be used toevaluate the maximum value that the introduction of secondary users can add to the conventional *** on assumptions of the PU s traffic model and some reasonable approximations,the ex-pression of OSE is obtained and the maximum achievable OSE is derived by solving an optimization *** results are verified by computer simulation.

关键词： cognitive radio opportunistic spectrum access opportunistic spectrum efficiency

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三维虚拟骨干网络算法优化

清华大学学报（自然科学版） 2008年第4期48卷 549-552页

作者：张昊钟晓峰王京清华大学电子工程系微波与数字通信技术国家重点实验室北京100084

由于ad hoc网络的实际应用环境多数为三维空间,该文将二维平面虚拟骨干算法推广到三维空间。首先利用图论中连通支配节点集(CDS)的概念,给出三维空间中虚拟骨干网络成形算法。然后通过推导给出该算法生成的三维虚拟骨干网络保持二维平... 详细信息

由于ad hoc网络的实际应用环境多数为三维空间,该文将二维平面虚拟骨干算法推广到三维空间。首先利用图论中连通支配节点集(CDS)的概念,给出三维空间中虚拟骨干网络成形算法。然后通过推导给出该算法生成的三维虚拟骨干网络保持二维平面中传输跳数稀疏比率为3,链路长度稀疏比率为6的性质,以及该算法所构建的连通支配节点集(CDS)的节点数目与理论最优数目的比率上限为16的结论。并通过大规模的随机仿真实验,验证了三维虚拟骨干网络算法的性能。

关键词：三维空间虚拟骨干网络连同支配节点集

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基于能效的单频网广播小区部署优化算法

清华大学学报（自然科学版） 2018年第2期58卷 170-174页

作者：陈皇卿钟晓峰王京清华大学电子工程系信息科学与技术国家实验室(筹)

与单小区多播/广播技术相比,多播/广播单频网络技术可以提高用户设备接收信号的频谱效率。使用单频网络将热门数据广播推送给目标用户设备,能够大大节约传输资源。在单频网络区域中对同一数据有需求的用户设备越多,使用广播推送能达到... 详细信息

与单小区多播/广播技术相比,多播/广播单频网络技术可以提高用户设备接收信号的频谱效率。使用单频网络将热门数据广播推送给目标用户设备,能够大大节约传输资源。在单频网络区域中对同一数据有需求的用户设备越多,使用广播推送能达到的能量效率越高。在连续广域覆盖网络下,该文提出一种基于能效指标的单频网广播小区部署优化算法,具有计算复杂度低的特点。基于随机几何蜂窝网络模型的仿真结果表明：与单播、单小区广播等模式相比,该算法能明显提升能量效率,提升程度与目标用户设备的分布紧密相关。

关键词：多播/广播单频网络广播小区能量效率多媒体数据推送随机几何

基于双线投影与线面约束的3D扫描测量系统研究

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红外与激光工程 2017年第4期46卷 133-139页

作者：王鹏史瑞泽钟小峰孙长库天津大学精密测试技术及仪器国家重点实验室天津300072

将双目传感器和线结构光有机地结合到一起,设计了一套能够对大尺寸被测物进行无导轨三维扫描的测量系统。通过标定实现双目传感器与结构光传感器坐标系的统一。提出了一种双线投影模型,实现了双目标记点的立体匹配和标记点传感器坐标的... 详细信息

将双目传感器和线结构光有机地结合到一起,设计了一套能够对大尺寸被测物进行无导轨三维扫描的测量系统。通过标定实现双目传感器与结构光传感器坐标系的统一。提出了一种双线投影模型,实现了双目标记点的立体匹配和标记点传感器坐标的测量。设计了基于线面约束的结构光测量模型,实现了物体表面光条三维信息的获取。采用空间几何相对不变性原则实现标记点传感器坐标和世界坐标的全局匹配,进而确定在测量位置处传感器坐标系与世界坐标系的转换关系。最终将传感器实时扫描测量的物体表面的三维点云数据转换到世界坐标系下,实现对被测物三维的扫描测量,工作距离下扫描测量精度优于0.08 mm。

关键词： 3D测量双线投影立体匹配线面约束

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基于时分系统的无线自组织网络同步算法

清华大学学报（自然科学版） 2005年第1期45卷 1-4页

作者：钟晓峰王有政梅顺良王京清华大学电子工程系微波与数字通信技术国家重点实验室北京100084

在基于时分系统的无线自组织网络和蜂窝通信网络的融合研究中,全网时间同步算法是其中的难点问题。该文提出了一种基于时分信道结构的自组织网络全网时间同步算法,利用系统的部分特定时隙收集自组织网络的拓扑结构信息,选取部分节点构... 详细信息

在基于时分系统的无线自组织网络和蜂窝通信网络的融合研究中,全网时间同步算法是其中的难点问题。该文提出了一种基于时分信道结构的自组织网络全网时间同步算法,利用系统的部分特定时隙收集自组织网络的拓扑结构信息,选取部分节点构建网络的"近似最小连通域",通过连通域中的节点广播系统同步信息,以完成全网的时间同步。通过理论分析和数据仿真,该算法的系统同步时隙开销为16.7%;在典型网络条件下,在一次全网同步中的节点同步成功概率不低于95%;较其他算法具有低复杂度、高可靠性、高同步效率。

关键词：移动通信时分多址(TDMA) 自组织网络同步