混合多址接入的无线传感器网络设计及实现

针对实际应用中无线传感器网络多区域分布、任务多元化的特点,为解决簇间通信的相互干扰,提出一种改进的FD-MA/TDMA混合机制的无线传感器网络.簇间采用FDMA避免干扰,簇内节点采用TDMA实现睡眠调度.此外,在TDMA机制中分配监测时隙,如有突发情况,簇内节点可通过CSMA竞争与簇头节点实现通信,以此增加上报的公平性.对系统进行了工程实现验证,测试证明达到预期效果.     

无线供电混合多址接入网络的资源分配

无线供电技术是延长无线网络节点寿命的有效方案。该文研究一个由基站和多个分簇用户组成的无线供电混合多址接入系统。系统的传输分为两个阶段。在第1阶段,基站向用户广播能量;在第2阶段,用户向基站传输信息。用户簇和用户簇之间采用时分多址接入,分时传输;同一簇内多个用户采用非正交多址接入,同时传输。该文研究联合优化系统的各阶段的传输时间、基站的发射功率、用户的发射功率等资源,分别以优化网络频谱效率和用户簇之间的公平性为目的,提出最大化网络吞吐量和最大化用户簇的最小吞吐量的联合资源分配算法。研究结果表明所提的两种算法分别能有效提高系统的频谱效率和保证用户簇之间的公平性。     

一种基于分簇的无线传感器网络路由协议的设计

在典型分簇协议LEACH的基础上，设计了一种新的路由协议LACHS。与LEACH不同，协议LACHS根据网络中节点的剩余能量动态选择集中式或分布式分簇算法。将协议LACHS与LEACH相比较，模拟实验结果表明：LACHS优于LEACH，能有效延长网络的生命周期；还考虑了拓扑结构的变化，从而保证了网络的稳定性。     

一种基于分簇的无线传感器网络路由协议的设计

在典型分簇协议LEACH的基础上,设计了一种新的路由协议LACHS。与LEACH不同,协议LACHS根据网络中节点的剩余能量动态选择集中式或分布式分簇算法。将协议LACHS与LEACH相比较,模拟实验结果表明:LACHS优于LEACH,能有效延长网络的生命周期;还考虑了拓扑结构的变化,从而保证了网络的稳定性。     

一种基于分簇的无线传感器网络路由协议的设计

在典型分簇协议LEACH的基础上,设计了一种新的路由协议LACHS.与LEACH不同,协议LACHS根据网络中节点的剩余能量动态选择集中式或分布式分簇算法.将协议LACHS与LEACH相比较,模拟实验结果表明:LACHS优于LEACH,能有效延长网络的生命周期;还考虑了拓扑结构的变化,从而保证了网络的稳定性.     

一种基于LEACH的无线传感器网络路由算法及仿真

在低功耗自适应分簇（LEACH,Low Energy Adaptive Clustering Hierarch）算法中,由于每一轮循环都要重新构造簇,距离较远的簇头节点可能会因长距离发送数据而过早耗尽自身能量,能量较低的节点当选为簇头节点时将会加速该节点的死亡,影响整个网络的生命周期。针对LEACH算法分簇机制中存在的不足,提出了一种改进的路由算法。仿真结果表明,改进算法通过考虑节点的剩余能量与固定分簇的方法,有效的改善了网络能量均衡,提高了网络生存时间。     

一种新的无线可充电传感器网络分簇算法

为了弥补现有无线可充电传感器网络充电效率低下和节点能量冗余并存的问题,提出了一种基于节点信息的分簇算法。首先,根据传感器节点的剩余能量状态,选择候选簇首。其次,计算候选簇首集合中节点之间的距离,并与基于节点密度的距离阈值比较,最终筛选出合适的簇首。其他节点根据就近原则选择簇首,形成对应的簇。该算法由于同时考虑节点剩余能量和簇首之间的距离,可以使得具有较多剩余能量的节点成为簇首,且簇首均匀分布整个网络中。仿真结果表明,提出的算法可以提高充电效率,减少节点的能量冗余或节点能量消耗过快而死亡的现象,从而有效延长整个网络的寿命。     

无线传感器网络LEACH协议的研究

在无线传感器网络中,与平面路由协议相比,分簇路由协议具有一定的优势.它具有拓扑管理方便、能量利用高效.数据融合简单等优点,成为当前路由协议研究的重点.本文以低能量自适应聚类(LEACH)为例,对分簇路由协议进行了分析.在此基础上,提出改进了的LEACH ED_LEACH(Base on Energy and Di Stance factors-Low-Energy Adaptive Clustering Hierarchy),通过使用MATLAB进行了仿真,仿真结果表明ED_LEACH算法能更有效地延长网络寿命.     

一种基于能量和距离的无线传感器网络分簇路由协议

在无线传感器网络的路由技术中,基于簇的路由算法在拓扑管理、能耗利用、数据融合等方面都有较强的优势.在分析EECS协议的基础上,提出了EECS协议存在的问题,并相应地修改了成簇算法,设计了ADEECS协议,增强了算法的能量均衡性能.在簇头选举阶段总是选择剩余能量最多的节点,在成簇阶段ADEECS协议同时考虑了节点的剩余能量和节点与基站的距离.仿真结果也证明了ADEECS协议相对于EECS很大地提高了网络的生命周期.     

无线传感器网络LEACH改进算法的设计与仿真

在众多的无线传感器网络分簇路由协议中,低功耗自适应分簇(Low Energy Adaptive Clustering Hierarchy,LEACH)算法是其中比较流行的协议之一,但它并没有考虑到每个节点的能量状态,而且最优簇首数一旦确定,整个网络通信期间不再改变,因而不能更有效地提高网络的生存时间.文章在LEACH协议的基础上提出了一种改进的高能效无线传感器网络协议-EECRP(an Energy Efficient Cluster Routing Protocol).仿真结果表明,与LEACH相比,EECRP具有更好的能量有效性,并且提高了无线传感器网络的寿命.     

基于压缩感知的无线传感器网络多目标定位算法

目标定位是无线传感器网络的重要应用场景。该文提出了一种将压缩感知应用于无线传感器网络多目标定位的方法,把基于网格的多目标定位问题转化为压缩感知问题。应用多分辨率分析的思想,设计了迭代回溯的压缩感知算法,该方法的特点是可同时进行多目标定位,并且大大减少了网络通信的数据量从而延长网络寿命,代价是融合中心的算法复杂度的增加。仿真结果显示,采用迭代回溯算法定位精度提高了50%以上,具有较好的多目标定位效果。     

移动无线传感器网络中MAC性能分析及改进

以往无线传感器网络中的媒体接入控制协议主要针对静止网络。当存在移动节点时。协议性能会大幅度降低。对存在移动节点的无线传感器网络中的媒体接入控制协议进行了性能分析，提出了改进算法。仿真结果验证了算法的有效性。最后给出了一种适合移动节点较多的场景的无线传感器网络媒体接入控制协议。     

基于OQAM-OFDM的NOMA通信系统设计

针对传统基于正交频分复用（OFDM）调制波形的非正交多址接入（NOMA）通信系统存在的旁瓣衰减较慢问题,提出了一种基于交错正交幅度调制的正交频分复用（OQAM-OFDM）波形的NOMA系统设计方案。所提设计方法通过在典型NOMA系统设计中加入OQAM预调制和滤波器组滤波等处理,有效加快旁瓣衰减,实现了较好的频域聚焦性能。仿真结果表明,提出的设计方法不仅有效提高了系统的频谱利用率,而且在抵抗多径干扰时误码率有所降低。虽然重点研究了通信下行链路,但是所得结论同样适用于上行链路。     

Defense against collusion scheme based on elliptic curve cryptography for wireless sensor networks

Wireless Sensor Networks (WSNs) are being deployed for a wide variety of applications and the security problems of them have received considerable attention. Considering the limitations of power, com-putation capability and storage resources, this paper proposed an efficient defense against collusion scheme based on elliptic curve cryptography for wireless sensor networks in order to solve the problems that sensor node-key leaking and adversaries make compromised nodes as their collusions to launch new attack. In the proposed scheme, the group-key distribution strategy is employed to compute the private key of each sensor node, and the encryption and decryption algorithms are constructed based on Elliptic Curve Cryptography (ECC). The command center (node) only needs to broadcast a controlling header with three group elements, and the authorized sensor node can correctly recover the session key and use it to decrypt the broadcasting message. Analysis and proof of the proposed scheme’s efficiency and security show that the proposed scheme can resist the k-collusion attack efficiently.     

A MAC protocol to support hybrid antennas in a wireless LAN

Hybrid Distributed Coordination Function （HDCF）, a modified medium access control protocol of IEEE 802.11 standard, is proposed in this paper to support both smart adaptive array antennas and normal omni-directional antennas simultaneously in one wireless LAN. Omni-directional antennas follow the standard Distributed Coordination Function （DCF） and smart antennas follow the Directional DCF （DDCF）. The proposed DDCF is based on Hybrid Virtual Carrier Sense （HVCS） mechanism, which includes Omni-directional Request-To-Send/Clear-To-Send （ORTS/OCTS） handshake mechanism and directional data transmission. HDCF is compatible with DCF. When a node transmits in a directional beam, the other nodes can multiplex the physical channel. Hence, HDCF supports Space Division Multiple Access （SDMA）. Simulation results show that HDCF can support hybrid antennas effectively and provide much higher network throughput and lower delay and jitter than DCF does.     

MST-based clustering topology control algorithm for wireless sensor networks

In this paper, we propose a novel clustering topology control algorithm named Minimum Spanning Tree (MST)-based Clustering Topology Control (MCTC) for Wireless Sensor Networks (WSNs), which uses a hybrid approach to adjust sensor nodes’ transmission power in two-tiered hierarchical WSNs. MCTC algorithm employs a one-hop Maximum Energy &; Minimum Distance (MEMD) clustering algorithm to decide clustering status. Each cluster exchanges information between its own Cluster Members (CMs) locally and then deliveries information to the Cluster Head (CH). Moreover, CHs exchange information between CH and CH and afterwards transmits aggregated information to the base station finally. The intra-cluster topology control scheme uses MST to decide CMs’ transmission radius, similarly, the inter-cluster topology control scheme applies MST to decide CHs’ transmission radius. Since the intra-cluster topology control is a full distributed approach and the inter-cluster topology control is a pure centralized approach performed by the base station, therefore, MCTC algorithm belongs to one kind of hybrid clustering topology control algorithms and can obtain scalability topology and strong connectivity guarantees simultaneously. As a result, the network topology will be reduced by MCTC algorithm so that network energy efficiency will be improved. The simulation results verify that MCTC outperforms traditional topology control schemes such as LMST, DRNG and MEMD at the aspects of average node’s degree, average node’s power radius and network lifetime, respectively.     

过饱和多址系统中QPSK非相干多用户信码/相位最佳联合检测

该文首先通过理论推导给出了过饱和多址系统中多用户信码/相位联合估计子。然后提出了低复杂度非相干多用户信码/相位最佳联合检测算法。此算法适用于具有二维星座的线性调制方式。通过计算机仿真实验,分析了此非相干最佳接收机的误码性能及相位提取误差等有关问题,并与相干最佳接收机作了比较,得出了一些有益的结论。     

A new privacy-preserving Euclid-distance protocol and its applications in WSNs

Recently, privacy concerns become an increasingly critical issue. Secure multi-party computation plays an important role in privacy-preserving. Secure multi-party computational geometry is a new field of secure multi-party computation. In this paper, we devote to investigating the solutions to some secure geometric problems in a cooperative environment. The problem is collaboratively computing the Euclid-distance between two private vectors without disclosing the private input to each other. A general privacy-preserving Euclid-distance protocol is firstly presented as a building block and is proved to be secure and efficient in the comparison with the previous methods. And we proposed a new protocol for the application in Wireless Sensor Networks (WSNs), based on the novel Euclid-distance protocol and Density-Based Clustering Protocol (DBCP), so that the nodes from two sides can compute cooperatively to divide them into clusters without disclosing their location information to the opposite side.     

基于平衡迭代规约层次聚类的无线传感器网络流量异常检测方案

针对现有网络流量异常检测方法不适用于实时无线传感器网络(WSN)检测环境、缺乏合理异常判决机制的问题,该文提出一种基于平衡迭代规约层次聚类(BIRCH)的WSN流量异常检测方案。该方案在扩充流量特征维度的基础上,利用BIRCH算法对流量特征进行聚类,通过设计动态簇阈值和邻居簇序号优化BIRCH聚类过程,以提高算法的聚类质量和性能鲁棒性。进一步,设计基于拐点的综合判决机制,结合预测、聚类结果对流量进行异常检测,保证方案的检测准确性。实验结果表明,所提方案在检测效果和检测性能稳定性上具有较为明显的优势。     

基于无线传感器网络的仓库智能安保系统设计

将无线传感器网络技术用于智能仓库安保系统。针对无线传感器网络技术和智能仓库安保系统的特点。设计了基于无线传感器网络的智能仓库安保系统的一整套系统和网络节点。该系统体现了无线传感器网络的特点。利用计算机处理信息,根据处理结果作出相应反应、处理。实验表明,该系统使用方便、稳定可靠。