解析无线个人域网

本文综述了当前几种发展极为迅速的无线个人域网技术,讨论了其演变过程及技术特点,并对其应用作了简要介绍,最后展望了WPAN在未来的广阔应用前景.     

基于6LoWPAN的物联网寻址策略研究

在6LoWPAN (IPv6 over Low-power Wireless Personal Area Network)的基础上,该文提出应用于物联网的寻址策略,实现基于IEEE 802.15.4协议的底层异构网络与互联网的实时通信。寻址策略包括IPv6地址自动配置和报头压缩。采用的分层地址自动配置策略,首先在底层网络内部允许节点使用16位短地址导出的链路本地地址进行数据分组传输,该链路本地地址需通过执行基于分簇的重复地址检测机制保证唯一性;其次,每个底层网络中的Sink节点通过上层IP路由器获取全球路由前缀,并与接口标识符相结合,形成Sink节点的全球地址,实现底层网络与互联网的数据交换。同时,通过在报头压缩编码中植入链路本地地址和全球地址控制位,提出了一种适用于物联网应用的报头压缩方案IIPHC (IoTs IPv6 Header Compression)。如果地址类型为链路本地地址,则采用简单灵活的IIPHC1方案,如果地址类型为全球地址,则采用相对复杂但有效的IIPHC2方案。仿真及测试结果表明,基于6LoWPAN的物联网寻址策略在网络开销、时延、吞吐量、能耗等性能方面存在一定的优越性。     

基于采样精度切换的毫米波无线通信空闲侦听机制研究

针对毫米波无线通信系统,提出了一种基于采样精度切换的低功耗空闲侦听方案,使得CSMA/CA下空闲侦听功耗与接收机解调所需高耗能模数转换器（ADC）功耗互相独立.具体而言,在空闲侦听状态,接收机使能极低功耗的1比特ADC和所提的1比特采样精度广义似然比包检测器来捕获突发包的到达;一旦捕获成功,接收机切换到原高精度ADC来解调数据包,进而保持了解调性能.该文推导并验证了所提方案中包到达检测器的虚警概率（FAP）和漏检概率（MDP）表达式.仿真结果表明,该方案与现有方案相比可显著降低空闲侦听功耗,并获得优异的检测性能.     

无线个域网实现技术的比较

详尽阐述了实现无线个域网的4种技术,比较了它们的产生背景、建立主旨、技术优势和市场前景,并对它们各自的发展作出了科学的预测。     

支持无线个域网协议远程互操作性测试的测试客户端

为解决无线个域网协议互操作性测试中距离限制的问题,通过转发设备的引入,借助互联网资源的辅助,提出远程互操作性测试平台的概念。针对无线个域网协议的特点设计平台客户端的总体结构,并根据具体的协议测试场景细化设计方案。通过典型的低速无线个域网协议6LoWPAN协议标准的测试实验结果来评估平台客户端的可用性。     

基于链路选择因子的高速无线个域网自适应时隙调度算法

本文提出了一种基于链路选择因子的高速无线个域网自适应时隙调度算法.在利用服务曲线对网络QoS需求进行建模的基础上,结合由链路质量获得的实时最优帧长,算法可以得出各个链路的选择因子.同时,选择因子的控制参数k能够决定调度算法的偏重点是链路质量还是业务QoS.仿真结果表明,该算法能在保证网络公平性的基础上有效地提高系统吞吐量.     

超宽带及其在无线个域网中的应用

近年来,超宽带(UWB)无线通信成为短距离、高速无线网络最热门的物理层技术之一。介绍了超宽带无线通信技术的概念及其信号传输过程中使用的关键技术,包括脉冲成形技术、调制技术以及接收技术,给出了超宽带无线传输系统的基本模型,最后分析了该技术在无线多媒体个域网中的应用。     

Adapting Cognitive Radio Technology for Low-Power Wireless Personal Area Network Devices

The application of wireless personal area network (WPAN) and simple point-to-point wireless communication devices has increased drastically both in private household and in our workspaces in general over the last decade. Combined with the fact that the total number of wireless devices and associated standards present in the wireless environment is experiencing an extreme growth, the frequency spectrum scarcity is exposed as a severe challenge. Setting up efficient and reliable wireless WPAN links can be challenging even today. This is especially true because of the intensive use of the license-free frequency bands, where the level of interference can be extremely high. Combined with the challenges associated with multi-path propagation and attenuation, setting up and maintaining an acceptable level of perceived QoS is a challenging job even for trained professionals. This paper discusses the challenges associated with the implementation of highly reliable low-power WPAN networks for the future and the adaption of Cognitive Radio technology as a potential solution. A brief status on the maturity of CR technology will be presented as an integral part of this discussion.     

一种快速传输的太赫兹无线个域网MAC协议

针对现有太赫兹无线个域网MAC协议存在信道利用率低的问题,提出一种快速传输的太赫兹无线个域网MAC(Fast Transmission MAC Protocol for THz Wireless Personal Area Network,FTP-MAC)协议,FTP-MAC协议采用多对节点并行传输机制,在信道互不干扰的情况下实现了多对节点在同一时刻内同时传输的功能,通过OPNET仿真工具进行仿真验证。相较于LODMAC协议和TAB-MAC协议,FTP-MAC协议在吞吐量、信道利用率和网络整体的数据传输效率等性能方面都有所提高。     

低速率无线个域网调制技术的研究

分析了IEEE 802.15.4 2006低速率无线个域网(LR-WPAN)标准的调制方法,并提出了一种选用多相Chirp序列作为其扩频序列和采用升余弦滚降脉冲成形的调制实现方法.对比了两种不同调制方法得到的连续相位线性调频信号的特征.     

低速率无线个域网调制技术的研究

分析TIEEE 802．15．4 2006低速率无线个域网（LR-WPAN）标准的调制方法，并提出了一种选用多相Chirp序列作为其扩频序列和采用升余弦滚降脉冲成形的调制实现方法。对比了两种不同调制方法得到的连续相位线性调频信号的特征。     

中继协作无线网络中不完美反馈下基于网络编码的重传方案

无线广播网络传输过程中,目的节点反馈信息丢失或部分丢失导致发送节点不能了解目的节点的真实接收状态.为提高不完美反馈下无线网络的重传效率,本文提出中继协作无线网络中不完美反馈下基于网络编码的重传方案.本方案基于部分可观察马尔科夫决策过程对不完美反馈下的重传过程进行建模.发送节点根据系统观测状态和最大置信度更新系统估计状态,根据数据包发送顺序,优先选择最早丢失且能够恢复最多丢包的编码包重传.目的节点缓存不可解编码包以提升编解码机会.重传过程中源节点关注目的节点请求包需求,相同情况优先选择传输可靠性较高的中继节点,以提升传输有效性.仿真结果表明,在不完美反馈下相对于传统方案,本方案可有效提高重传效率.     

多源多中继无线网络中基于随机线性网络编码的调度方案

现有多中继无线网络中传输调度方案主要针对单信源且转发链路状态相同的情况,多采用顺序转发的调度方式,传输效率较低。针对此问题,该文提出一种基于随机线性网络编码的优先级调度方案。该方案在不同的传输阶段,利用信息包接收状态或编码向量之间的线性关系生成反馈信息,计算中继节点的有效信息包数。在转发链路状态不同的情况下,综合考虑各中继节点的有效信息与链路传输可靠性,确定优先级,从而完成调度。该方案实现了多中继对多信源信息的协同转发,在转发链路状态差异较大时,能自适应地选择最优转发节点和路径,提高信息包的传输成功率。仿真结果表明,相比传统基于单信源或顺序调度的方案,该方案能有效提高网络吞吐量,减少重传次数。     

一种基于随机密钥的无线传感器网络加密方案

密钥的建立与管理是无线传感器网络安全的重要且基础的组成部分,是影响大规模应用的一个关键问题。近来,密钥建立与管理成为无线传感器网络安全领域一个活跃的研究分支。提出一种基于随机密钥预分配的无线传感器网络加密方案。该方案通过密钥互斥机制解决传统随机密钥预分配方案中点到点数据源认证问题。     

An Intra-PAN Mobility Management Scheme for IPv6 over Low-Power Wireless Personal Area Networks

This paper proposes an intra-PAN mobility management scheme for IPv6 over Low-power wireless personal area networks （6LoWPAN） on the basis of ＂networkbased＂ idea. We developed a tree-like network architecture which includes coordinate nodes for packet routing. All of the control messages are designed to transmit in link layer, and the sensor nodes are free to consider care-of address and the mobile nodes are unnecessary to deal with any mobility handoff messages. The simulation results show that this scheme efficiently cuts down the signaling cost and reduces the energy consumed by fixed nodes which can extend the life time of the whole Personal area networks （PAN）.     

An Efficient Adaptive Modulation Scheme for Wireless OFDM Systems

An adaptive modulation scheme is presented for multiuser orthogonal frequency‐division multiplexing systems. The aim of the scheme is to minimize the total transmit power with a constraint on the transmission rate for users, assuming knowledge of the instantaneous channel gains for all users using a combined bit‐loading and subcarrier allocation algorithm. The subcarrier allocation algorithm identifies the appropriate assignment of subcarriers to the users, while the bit‐loading algorithm determines the number of bits given to each subcarrier. The proposed bit‐loading algorithm is derived from the geometric progression of the additional transmission power required by the subcarriers and the arithmetic‐geometric means inequality. This algorithm has a simple procedure and low computational complexity. A heuristic approach is also used for the subcarrier allocation algorithm, providing a trade‐off between complexity and performance. Numerical results demonstrate that the proposed algorithms provide comparable performance with existing algorithms with low computational cost.     

基于802.16e协议的指挥所无线局域网

文章介绍了基于IEEE802.16e协议的野战指挥所无线局域网的框架设计。首先简要介绍了802.16e协议,其次提出了基于802.16e协议的野战指挥所无线局域网的设计方法。对于野战条件下,快速、高效组建野战指挥所无线局域网,提供保密、实时、可靠、高速、大容量、多类型的业务具有一定的借鉴意义。     

Energy Harvesting Based Efficient Routing Scheme for Wireless Sensor Network

Wireless Sensor Network were deployed in a complex environment where the wide range of complex application is mandatory for the services. Such application includes military, agriculture, healthcare, defense, monitoring, surveillance etc. In general sensor nodes were spatially distributed and deployed in remote fashion, usually they are powered up by batteries. These battery powered sensor nodes are pruned to failure due to its power constrained nature. This led many researchers to explore energy efficient context aware routing for Wireless Sensor Networks. Hence a novel energy harvesting based efficient routing scheme is desirable to address the above stated problem. The key idea is to harvest the energy source from the deployed environment. The proposed routing scheme is tested and validated in MATLAB based simulation test bed. The experimental results shows that the proposed routing scheme is robust and meet all the requirements of routing and promising results for energy usage.     

一种基于树的无线传感器网络数据收集方法

该文提出一种基于树的无线传感器网络数据收集方法,它将查询请求的传递与数据回传结构的建立有机结合起来,通过使用一种洪泛避免的方法传递查询请求,建立起一棵以sink节点为根的、包含最少中间节点的查询转发树,作为数据回传结构。理论分析和仿真试验表明,该方法不会降低无线传感器网络的连通性,可以有效节省能量。     

An Active Millimeter-Wave Imager Based on MIMO-SAR Scheme

Journal of Infrared, Millimeter, and Terahertz Waves - In this article, an active millimeter-wave imager based on multiple-input multiple-output synthetic aperture radar (MIMO-SAR) scheme is...