无线网络拓扑瞬态时变干扰下的信号分解模型仿真

无线网络拓扑结构容易受到瞬态时变干扰。为了保证信号的完整性,采用自适应滤波器对瞬态时变干扰进行滤除,并建立信号分解模型对信号进行分解。不同调频信号在不同信噪比下进行仿真实验表明,针对同一子带,该方法增加幅度低,得到的实验结果优;针对分解结果,该方法的分解次数较集成经验模态分解方法更少,且频率过度更加自然;在该分解方法的Hilbert谱图中,频率分量清晰明确,证明了该模型在无线网络拓扑瞬态时变干扰下可以对信号进行合理准确的分解。

基于关联规则引导遗传算法的高可靠性无线网络拓扑设计

无线网络中的节点与路径故障会产生惩罚性网络成本,该成本是无线网络的一个重要性能指标,对此提出了一种基于关联规则引导遗传算法的高可靠性无线网络拓扑设计算法。首先,采用Monte Carlo模拟器将网络模拟为图结构;然后,采用Apriori算法提取模拟器数据的关联规则;最后,利用提取的关联规则引导遗传算法的变异与交叉操作,搜索最优的网络拓扑结构。仿真实验结果表明,对于多个网络规模,该算法均可获得较好的网络性能与收敛速度,具有较好的实用性。

基于ZigBee无线网络的温湿度监测系统

为克服有线温湿度监测系统存在的诸如线路多、布线复杂、维护困难等不足,针对大棚温室、粮库仓储等的温湿度监测应用需求,将传感器与ZigBee无线通信技术相结合,提出了无线温湿度信息监测系统设计方案,并详细论述了监测系统的网络结构、硬件模块设计和软件设计,实现了点对点星型结构的无线传感器网络。研究结果表明,该无线化的温湿度信息监测系统具有系统结构简单、可靠性与扩展性好、布点灵活等特点。

无线超宽带通信技术星载应用研究

采用无线通信实现电气互连可以有效缓解星上电缆布局难、维护难、更改难等问题。相比窄带连续波无线通信,超宽带通信技术具有功率谱密度低、信号分辨率高、频谱共存能力强、信道容量大、复杂度低等特点,具有较好的应用前景。欧洲Eu:CROPIS卫星、日本ETS-9卫星、国际空间站哥伦布实验舱等已经开展了无线超宽带通信的应用研究和演示验证。针对星上高可靠、低时延、可扩展无线组网需求,分析了多跳分簇网络拓扑、无线信号传输模型、无线传输电磁干扰模型、高精度时间同步、灵活组网与可靠传输等关键技术和解决途径,形成适用于星上无线传输的通信技术体制和解决方案,为卫星少缆化、无缆化通信奠定技术基础。

An efficient reliability evaluation method for industrial wireless sensor networks

Aimed at the difficulties in accurately, comprehensively and systematically evaluating the reliability of industrial wireless sensor networks （WSNs）, a time-evolving state transition-Monte Carlo （TEST-MC） evaluation method and a novel network function value representation method are proposed to evaluate the reliability of the IWSNs. First, the adjacency matrix method is used to characterize three typical topologies of WSNs including the mesh network, tree network and ribbon network. Secondly, the network function value method is used to evaluate the network connectivity, and the TEST-MC evaluation method is used to evaluate network reliability and availability. Finally, the variations in the reliability, connectivity and availability of these three topologies are presented. Simulation results show that the proposed method can quickly analyze the reliability of the networks containing typical WSN topologies, which provides an effective method for the comprehensive and accurate evaluation of the reliability of WSNs.

QoS Adaptive Topology Configuration in Synchronous Wireless Sensor Networks

By using hyper-graph theory,this paper proposes a QoS adaptive topology configuration(QATC) algorithm to effectively control large-scale topology and achieve robust data transmitting in synchronous wireless sensor networks.Firstly,a concise hyper-graph model is abstracted to analyze the large-scale and high-connectivity network.Secondly,based on the control theory of biologic 'Cell Mergence',a novel self-adaptive topology configuration algorithm is used to build homologous perceptive data logic sub-network ...

A Frameless Network Architecture for the Way Forward of C-RAN

The key technologies involved in the evolution of the Cloud-based Radio Access Network(C-RAN) are discussed in this paper. Taking the Frameless Network Architecture(FNA) as a starting point, a cell-lessbased network topology for a multi-tier Heterogeneous Network(Het Net) and ultra-dense network is proposed. The FNA network topology modeling is researched with centralized processing and distributed antenna deployments. The Antenna Element(AE) is released as a new dimensional radio resource that is included in the centralized Radio Resource Management(RRM) processes. This contributes to the on-demand user-centric serving-set associations with cell-edge effect elimination. The Control Plane(CP) and User Plane(UP) separation and adaptation are introduced for energy efficiency improvements. The centralized RRM and different optimization goals are discussed for fully exploring the merits from the centralized computing of C-RAN. Considering the complexity, near-optimal approaches for specific users' Quality-of-Service(Qo S) requirements are addressed. Finally, based on the research highlighted above, the way forward of C-RAN evolution is discussed.

Network Lifetime Global Optimization for Multi-Source and Single-Sink Topology in Wireless Sensor Networks

The multi-source and single-sink(MSSS) topology in wireless sensor networks(WSNs) is defined as a network topology,where all of nodes can gather,receive and transmit data to the sink.In energy-constrained WSNs with such a topology,the joint optimal design in the physical,medium access control(MAC) and network layers is considered for network lifetime maximization(NLM).The problem of integrating multi-layer information to compute NLM,which involves routing flow,link schedule and transmission power,is formulated as a nonlinear optimization problem.Specially under time division multiple access(TDMA) scheme,this problem can be transformed into a convex optimization problem.To solve it analytically we make use of the property that local optimization is global optimization in convex problem.This allows us to exploit the Karush-Kuhn-Tucker (KKT) optimality conditions to solve it and obtain analytical solution expression,i.e.,the globally optimal network lifetime(NL).NL is derived as a function of number of nodes,their initial energy and data rate arrived at them. Based on the analysis of analytical approach,it takes the influence of data rates,link access and routing method over NLM into account.Moreover,the globally optimal transmission schemes are achieved by solution set during analytical approach and applied to algorithms in TDMA-based WSNs aiming at NLM on OMNeT++ to compare with other suboptimal schemes.