Layered D2D NOMA

This paper investigates a layered power allocation(PA)non-orthogonal multiple access(NOMA)scheme for device-to-device(D2D)relaying networks,where the strategy of partial data transmission at relay nodes are adopted to improve the efficiency of resources.In addition,to satisfy different quality-of-service(QoS)requirements from multiple users,layered and grouped manners are involved.Moreover,the closed-form expressions in terms of the sum-rate(SR)and outage probability of the proposed scheme are derived for independent Rayleigh fading channels,which demonstrates our theoretical analysis.Both analytical and simulation results are provided to show the superiority of our proposed scheme compared with existing works.     

3D structure from 2D motion

This article motivates the structure from motion (SfM) approaches by describing some current practical applications. This is followed by a brief discussion of the background of the field. Then, several techniques are outlined that show various important approaches and paradigms to the SfM problem. Critical issues, advantages and disadvantages are pointed out. Subsequently, we present our SfM approach for recursive estimation of motion, structure, and camera geometry in a nonlinear dynamic system framework. Results are given for synthetic and real images. These are used to assess the accuracy and stability of the technique. We then discuss some practical and real-time applications we have encountered and the reliability and flexibility of the approach in those settings. Finally, we conclude with results from an independent evaluation study conducted by industry where the proposed SfM algorithm compared favorably to alternative approaches     

带有特征感知的D2D内容缓存策略

设备到设备通信(D2D)可以有效地卸载基站流量,在D2D网络中不仅需要共享大众化内容还需要个性化内容缓存。该文对缓存内容选择问题进行了深入研究,提出一种结合特征感知的内容社交价值预测(CSVP)方法。价值预测不仅可以降低时延也可以减少缓存替换次数降低缓存成本。首先结合用户特征和内容特征计算内容当前价值,然后通过用户社交关系计算未来价值。微基站根据内容的价值为用户提供个性化内容缓存服务,宏基站则在每个微基站的缓存内容中选择价值较大部分的内容。仿真结果表明,该文提出的缓存策略可以有效缓解基站流量,与其他方法相比降低时延约20%～40%。     

Device-to-Device通信的无线资源管理研究

在IMT-Advanced蜂窝网络中部署设备至设备(D2D:Device-to-Device)通信是当前无线领域内的一个研究热点,其主要的困难在于控制D2D与蜂窝系统间的干扰。D2D的无线资源管理机制和算法是实现系统间干扰协调的关键因素之一。文章从功率控制、资源调度和模式选择3个方面,介绍了D2D无线资源管理研究领域的最新成果和进展,并对未来发展方向进行了分析展望。     

3D dense reconstruction from 2D video sequence via 3D geometric segmentation

3D reconstruction is a major problem in computer vision. This paper considers the problem of reconstructing 3D structures, given a 2D video sequence. This problem is challenging since it is difficult to identify the trajectory of each object point/pixel over time. Traditional stereo 3D reconstruction methods and volumetric 3D reconstruction methods suffer from the blank wall problem, and the estimated dense depth map is not smooth, resulting in loss of actual geometric structures such as planes. To retain geometric structures embedded in the 3D scene, this paper proposes a novel surface fitting approach for 3D dense reconstruction. Specifically, we develop an expanded deterministic annealing algorithm to decompose 3D point cloud to multiple geometric structures, and estimate the parameters of each geometric structure. In this paper, we only consider plane structure, but our methodology can be extended to other parametric geometric structures such as spheres, cylinders, and cones. The experimental results show that the new approach is able to segment 3D point cloud into appropriate geometric structures and generate accurate 3D dense depth map.     

D2D技术在LTE-A系统中的应用

Device-to-Device（D2D）是一种在LTE-A系统中通过重用小区内宏蜂窝用户的资源来实现端到端通信的新型技术。本文从实际应用的角度出发,首先对D2D技术的原理和应用进行了分析,然后讨论D2D技术应用于LTE-A系统中的优缺点,接着通过仿真验证了D2D技术在LTE-A系统中的优势。最后阐述了D2D技术在LTE-A系统中应用可研究的方向及技术展望。     

D2D技术在LTE-A系统中的应用分析

由于移动通信技术的飞速发展,第三代的移动通信技术及设备已经从最开始的理论性逐渐的走向了商用。在整个移动通信的业界中,各大通信业的巨头们加大了对下一代无线通信网络的开发和探索,比如"3GPP"的长期演进(LTE),以及IEEE802.16m等方面的研究。不仅如此,对3GPP进行研究的同时,对LTE-A系统进行了更为深入详细的研究。对于这些系统而言,无论是系统的演进,还是系统的发展将"未来移动蜂窝网络(IMT-A)"作为主要的支持背景,在该范畴下展开的,如此众多的IMT-A系统,在小区蜂窝的网络背景下,允许支持Device-to-Device(D2D),其主要的目的是进一步的提高频谱利用率。文章主要针对D2D技术在LTE-A系统中的应用进行研究,首先介绍了D2D通信的原理及应用,然后对其仿真结果进行研究和分析,并提出展望,以期对D2D技术的良好应用,起到相应的参考帮助。     

D.D.A. notch filter

A filter, based on digital-differential-analyser-type elements, for mains-interference rejection is described.     

A/D和D/A转换器

7846RP 16位D/A转换器适合于空间飞行应用,根据 轨道不同,可以承受高于100krad（千拉德）的辐射。该转 换器具有正和负基准输入特性,并有一个片上输出放大器, 用户可以选择单极或者双极输出。     

NOMA增强型D2D通信的资源分配算法

传统蜂窝网络中,多址接入技术起着尤为关键的作用,与正交多址（Orthogonal Multiple Access,OMA）技术相比,非正交多址（Non-Orthogonal Multiple Access,NOMA）能够支持的用户数量远远超过可用正交资源的数量,可以达到更高的频谱效率和用户公平性。因此,为提高异构蜂窝网络的整体容量,本文研究了NOMA增强型设备到设备（Device to Device,D2D）的资源分配问题,并将其分解为两个独立的子问题:信道分配和功率控制。一方面,基于Coalition博弈为D2D组分配合适的信道;另一方面,对D2D发送功率和功率分配因子依据可行解域进行联合优化,以最大化整个网络中D2D可实现速率。仿真结果表明所提算法在保证系统性能的同时,还可以有效降低计算复杂度。      

基于干扰对齐的D2D混合网络干扰管理研究

针对如何有效抑制蜂窝与D2D混合网络中的干扰问题,提出了一种基于干扰对齐的干扰协调策略。通过建立k对D2D用户(DUE)复用蜂窝用户(CUE)上行资源的干扰模型,并分别在发送端和接收端设计发送干扰抑制预编码,使得在某一接收端处的干扰均对齐在接收信号的零空间上,从而抑制区内和区间两大干扰。仿真证明,文中所提出的基于干扰对齐的功率分配方案,比其他算法能获得更大的系统总速率,从而最大化混合网络的自由度。     

基于链路间干扰辅助的中继D2D系统安全通信方法

在包含中继节点的D2D(Device-to-Device)系统中,针对蜂窝链路与D2D链路同时受窃听的问题,提出一种基于链路间干扰辅助的中继D2D系统安全通信方法.首先,确定蜂窝链路与D2D链路上下行发送模式;然后,在基站与中继节点的发送信号中添加人工噪声,协作干扰窃听者;最后,对基站功率分配与D2D功率控制进行了优化,以实现不同类型链路间干扰辅助保障系统安全.仿真结果表明,所提出的安全通信方法在保密速率方面比SVD(Singular Value Decomposition)与ZF(Zero-Forcing)预编码方法提高了1.5bit/s/Hz.     

D2D研究现状及发展前景

LTE Device to Device(D2D)Proximity Services(LTE终端直通近距离服务)即我们熟知的LTE-D2D(端到端)技术。2013年,D2D成为3GPP组织重点研讨技术之一,其标准化工作正在讨论完善之中。LTE-D2D是在LTE-A系统(辅助)控制或无网络基础设施的情况下,用户设备在授权频段上直接进行通信的技术。它的出现将在一定程度上缓解无线频谱资源匮乏的问题,并能够提升蜂窝系统频谱效率。文章对D2D通信的发展历程、场景和关键技术进行了介绍,最后展望D2D技术发展前景及在未来应用中的情况。     

Full Duplex DD for In-Band D2D Communication

Wireless Personal Communications - Device to device (D2D) communication is a candidate technology to ascertain the 5G wireless system. To implement the D2D communication in an in-band cellular...     

图像导引介入治疗中可视化3D的2D/3D图像数据分析

三维成像对许多医学过程(根本上是对患者的健康)来说,是非常关键的。本文探讨了三维成像方法的与众不同之处,以及作为一种不断发展创新的技术,临床医生们对它的需求和期待。     

Retrieval of 3D shapes using volume D2

Searching out goal shapes from 3D model databases has been a hot topic in many fields. A simple and successful method called volume D2 to retrieve models by volumetric distributions is proposed. Experimental results show that the method outperforms popular surface distribution approaches.     

A/D和D/A转换器IC

代码转换器提高DSP效率 TLV320AIC10 16位代码转换器提供连续数据传输,可支持DSP自动缓冲单元,减少因缓冲(最高达64kB)不足而引起的中断。该器件特性有每秒22k的采样速率,一个串行接口,增益范围为-36～24dB的可编程增益放大器,一个2:1模拟多路复用器,以及节能备用模式。其它性能包括:工作电压3～5.5V,在采样速率为每秒8k时功耗为39mW。