基于无线信道指纹的室内位置感应系统分析(英文)

This paper reviews and analyses various simplified-RFID (Radio Frequency Identification) indoor location systems, and proposes an improved implementation based on the propagation channel "fingerprinting" principle. The focus of the design aims to provide accurate location estimation, while minimising infrastructural requirements. The proposed approach is based on the LANDMARC (Indoor Location Sensing Using Active RFID) with Virtual Reference tags (VIRE) and implemented with dynamic linear interpolation and ...     

一种基于投票的VANET位置验证方法

位置欺骗严重影响了车载自组织网络（VANET）的安全,解决位置欺骗的有效方法是对位置验证。VANET中的位置验证受到了研究人员关注,针对基于最小均方误差（MMSE）的位置验证方法准确性不高的问题,为更高效准确地检测出位置欺骗,提出了一种基于投票的VANET位置验证方法,在此基础上,对所提出的方法进行了安全性分析和实验仿真,结果表明,此方法的性能优于基于MMSE的位置验证方法。     

车载GPS：时间就是机会

如今在欧洲和北美的大部分地区，车载GPS导航系统已经成为中档以上家用汽车的标准配置。通过完善的电子地图的配合，每一个驾驶即使对道路情况完全陌生也可以轻松到达目的地。而在地域广大，道路交通情况相对复杂的中国，GPS系统则有更大的发展空间。那么，目前在国内发展状况怎么样呢?实际使用中，车载GPS系统究竟可以带给我们多少方便?为此记采访了国内较早从事车载GPS应用的北京奥星天网公司负责人。     

基于轻量化网络的车载雷达目标分类方法

针对现有车载毫米波雷达目标分类方法存在静止杂波干扰和网络模型复杂度高的问题,本文将Ghost模块和MobileNet相结合设计了G?MobileNet轻量化神经网络,并提出了一套完整的车载毫米波雷达目标分类流程。首先对雷达原始AD采样信号进行向量均值相消处理,滤除静止杂波,再进行二维快速傅里叶变换（FFT）得到目标的距离?多普勒（RD）图像,最后使用G?MobileNet对RD图像特征进行提取及分类得到分类结果。实测数据处理结果表明,所提方法能够消除静止杂波对多普勒特征产生的干扰,且分类网络模型复杂度低,在具有较高的分类准确率的同时节省了网络模型储存空间和运行网络所需内存。     

基于流量感知的网络切片资源智能分配方法

针对当前网络切片资源仅考虑时间域请求所导致切片资源分配不合理的问题,采用基于残差-预测框架的流量感知算法来预测网络流量,结合神经网络预测未来的网络负载状态;基于网络负载预测结果,利用VNF技术实现网络切片资源智能分配.实验表明,该方法能够提升虚拟服务功能链数据包调度的端到端时延和CPU利用率.     

基于5G网络切片的车联网资源分配优化方法

由于传统的资源分配方法存在一定不足,故文章提出了基于5G网络切片的物联网资源分配优化方法。首先,对5G切片的资源分配优化方法进行设计,如建立资源分配模型;其次,基于5G网络切片建立资源分配算法;最后,构建边缘服务器资源分配机制,基于以上步骤完成资源分配方法的设计。为验证所设计方法的有效性,文章建立了对比实验,选取基于灰狼优化和匈牙利算法的D2D资源分配策略与基于云雾混合计算的车联网联合资源分配算法作为对比方法对比3种方法性能,最终得出所提方法资源分配时间最短,有效性更高。     

频域松弛方法(英文)

本文叙述一种计算多频率信号激励的非线性电路静态响应的有效算法。这种算法是以频域的松弛方法为基础。每步迭代的解是由非线性元件引起的互调信号中每一频率成份作用于时不变电路的计算而获得的。     

基于LTE网络的物联网的随机时延分析(英文)

An Long Term Evolution (LTE) network based mobile Internet of Things (IoT) is modeled and analyzed with the probabilistic delay distribution as the main interest. Stochastic network calculus is relied on to conduct the analysis. Two typical traffic models, i.e., Compound Poisson and Aggregated ON-OFF Source, are analyzed. The wireless fading channel is modeled as a Gilbert-Elliot channel. Numerical results are presented, where the probabilistic delay distribution and guaranteed capacity under certain delay ...     

基于代价函数的通道误差校正方法(英文)

方位多通道技术是合成孔径雷达(SAR)实现高分宽测的手段之一。在多通道系统中通道失配是不可避免的,这会导致SAR 图像模糊。已有的通道失配校正方法大多依赖于系统参数以及场景内容。参数的不确定性将会大大降低校正算法的稳定性。该文提出了一种改进的通道失配校正方法,根据失配产生的原因,将通道失配分为距离增益误差、脉冲采样时钟误差和传输相位误差3 项。前两项误差通过交替估计进行补偿,而传输相位误差则通过代价函数给予估计。该方法对成像场景的依赖较小,基于机载多通道验证平台实测数据的实验验证了该方法的有效性。      

基于OpenFlow的移动自由空间光网络的控制架构(英文)

Mobile free space optical networks have aroused much attention due to the ability of providing high speed connectivity over long distance using the wireless laser links,while requiring relatively high available bandwidth resource and less energy consumption.However,maintaining the network with laserlinks is quite challenging due to a number of issues,such as the link fragility,the difficulty in pointingand tracking of the link,which also raises the great difficulty in the control of the network.In this paper,we present the methodology for the deployment of the mobile freespace optical networks based on our proposed OpenFlow-based control architecture.In addition,a new routing scheme is proposed and demonstrated on the testbed based on this control architecture.Delivery ratio,average delivery delay and time complexity are given to verify the performance of the OpenFlow-based control architecture.     

Location Verification Systems in Emerging Wireless Networks

As location-based techniques and applications have become ubiquitous in emerging wireless networks, the verification of location information has become more important. In recent years, there has been an explosion of activity related to lo- cation-verification techniques in wireless networks. In particular, there has been a specific focus on intelligent transport systems because of the mission-critical nature of vehicle location verification. In this paper, we review recent research on wireless location verification related to vehicular networks. We focus on location verification systems that rely on for- mal mathematical classification frameworks and show how many systems are either partially or fully encompassed by such frameworks.     

基于概率策略逻辑的VANET信息广播模型定量验证方法研究

VANET网络中信息的发送和接收具有随机性和不确定性,IEEE 802.11p广播协议无法适应VANET网络拓扑动态变化,于是研究者们根据不同环境中的具体应用需求提出了各种VANET广播协议,如何对新提出的协议的性能以及可靠性进行分析与验证是一个关键性问题.自动化的定量验证技术能够针对系统需要满足的多个性质进行分析,并给出满足需求的最大或者最小概率.然而研究人员在进行定量验证过程中使用的PTCL、rPATL等逻辑语言都不能够明确描述用户的策略是什么,因此本文提出基于概率策略逻辑的模型定量验证方法.该方法首先对系统中的多个角色使用概率时间接口自动机对其行为建模,然后使用概率策略逻辑语言对系统需要满足的性质进行描述,最后基于定量验证算法自动给出系统相关性质的分析结论.本文将该方法应用到VANET信息广播协议性能分析上,能够针对外界环境的变化选择合理的策略,从而分析出不同环境下信息广播发送成功的最大概率.     

云计算中抗共谋攻击的数据位置验证协议

针对云计算中数据位置验证存在的共谋攻击,本文提出了抗共谋攻击的数据位置验证协议.首先给出了数据位置验证的系统模型,分析了安全威胁,并给出了数据位置验证的安全定义.随后,将安全定位协议与数据持有性证明协议相结合,设计了一维空间下的数据位置验证协议,并证明了所提协议满足安全定义且能抵御共谋攻击.在一维协议基础之上,构建了三维空间下的数据位置验证协议.最后,在三维空间下将本文所提协议与Lost协议和Geoproof协议进行了性能的测试和比较.结果表明所提协议能够验证服务器具体位置且能抵御共谋攻击.     

AMOEBA: Robust Location Privacy Scheme for VANET

Communication messages in vehicular ad hoc networks (VANET) can be used to locate and track vehicles. While tracking can be beneficial for vehicle navigation, it can also lead to threats on location privacy of vehicle user. In this paper, we address the problem of mitigating unauthorized tracking of vehicles based on their broadcast communications, to enhance the user location privacy in VANET. Compared to other mobile networks, VANET exhibits unique characteristics in terms of vehicular mobility constraints, application requirements such as a safety message broadcast period, and vehicular network connectivity. Based on the observed characteristics, we propose a scheme called AMOEBA, that provides location privacy by utilizing the group navigation of vehicles. By simulating vehicular mobility in freeways and streets, the performance of the proposed scheme is evaluated under VANET application constraints and two passive adversary models. We make use of vehicular groups for anonymous access to location based service applications in VANET, for user privacy protection. The robustness of the user privacy provided is considered under various attacks.     

一种位置服务解决方案

移动通信和定位技术的结合,是当前通信市场一个新的业务增长点,本文介绍了在移动通信系统中常用的定位技术,提出了一种位置服务(LBS)的解决方案,并给出了一个简单的定位业务实例,最后,简单讨论了移动位置服务的发展前景.     

Mixing greedy and predictive approaches to improve geographic routing for VANET

In recent years, thanks to the development and popularization of wireless network technologies, the issue of vehicular ad hoc network (VANET) has received great attention, and more and more VANET‐related researches have been brought up. Generally speaking, the biggest difference between VANET and traditional ad hoc network is the velocity of carriers because in VANET, the velocity of vehicles, the carriers, is much higher than those in traditional ad hoc. Therefore, it would be a great challenge to forward data efficiently in VANETs and many researches proposed have focused on the development of routing protocols. The current proposed routing protocols are all assumed to simulate in a distributed and ideal environment. As for the complex geographic environments, such as urban scenarios, extra amendments must be needed to improve the efficiency of the routing protocols. Thus, the main purpose of this paper is to design a suitable routing protocol for urban scenarios with better performance and adaptability. For this reason, greedy on straight roads and predictive at the intersections (GSPI) routing protocol is proposed to use greedy mode on straight roads and to use predictive mode at the intersections. In greedy mode, we choose the next hop according to the weight value that combines the distances and multi‐rate. In predictive mode, we predict the directions of the vehicles to determine the next hop. The simulation results reveal that our proposed algorithm indeed proves its feasibility. Copyright © 2010 John Wiley & Sons, Ltd.     

位置指纹定位技术

在室内利用无线网络对移动目标定位,可用的技术有基于波达时间(TOA/TDOA)、基于波达角度(AOA)、以及基于接收信号强度(RSS)的技术等。比较而言,基于接收信号强度(RSS)的位置指纹(LF)技术更适合于复杂的室内环境。对该技术目前的研究情况进行比较全面和详细的介绍。     

航空发动机位置检测电路设计

航空发动机位置检测是发动机的重要检测项目,位置检测可以通过在检测位置加装专用电阻式位置传感器来实现,电阻式位置传感器将位置的变化转换成与之呈线性关系的电阻值的变化,然后再经阻值测量电路,实现对位置信号的测量。本文设计了一种基于恒流源方法的阻值检测电路,较好地解决了发动机位置检测的问题。     

无源多站时差定位技术研究及在频谱监测中的应用

研究了无源定位中时差定位的方法及其应用。通过此方法来确定在频谱监测系统中检测到的发射异常信号的信源位置。仿真实验证明本定位方法切实可行,并且在实践中有很好的指导意义。