基于加权信任优化的传感器网络安全实现

In this paper, an optimized malicious nodes detection algorithm, based on Weighted Confidence Filter (WCF), is proposed to protect sensor networks from attacks. In this algorithm, each cluster head in a cluster-based hierarchical network figures out an average confidence degree by means of messages from its child nodes. The cluster head only accepts a message from the child node whose confidence degree is higher than the average. Meanwhile, it updates the confidence degrees for each of its child nodes by comparing the aggregation value and the received messages, and regards them as the weight of exactness of messages from nodes. A sensor node is judged to be malicious if its weight value is lower than the predefined threshold. Comparative simulation results verify that the proposed WCF algorithm is better than the Weighted Trust Evaluation (WTE) in terms of the detection ratio and the false alarm ratio. More specifically, with the WCF, the detection ratio is significantly improved and the false alarm ratio is observably reduced, especially when the malicious node ratio is 0.25 or greater. When 40% of 100 sensors are malicious, the detection accuracy is above 90% and the false alarm ratio is nearly only 1.8% .     

LTE系统中基于PSS的抗大频偏和噪声的同步方法

传统的同步算法是将接收到的数据与本地的PSS进行相关,它的同步效果较好但是抗频偏能力很差。利用PSS信号在时域结构的对称性对接收到的半帧数据进行63点的相关运算,获取估计疑似同步位置,然后对各个疑似同步位置进行滑动相关得同步位置。同时,对多个无线帧的接收信号在高斯信道和LTE多径信道中分别进行了仿真,结果表明本文算法在性能和抗频偏能力方面较传统的算法有了明显的提高。     

无线传感器网络中自适应动态簇维护

层次型分簇的网络体系结构在无线传感器网络中应用非常广泛,然而,这样的网络结构大多数需要对其周期性的维护。周期性簇维护会带来大量的不必要的能量消耗,而传感器节点的能量是极其有限的。因此,本文提出一种非周期性的自适应动态簇维护方案,即在通信过程中,如果某个簇受到攻击,那么簇维护就仅仅在受到攻击的簇内进行,其它的簇依然维持原来的工作状态。由于该方案打破了周期性簇维护的思想,引入了谁受到攻击谁就进行维护的思想,所以减少了网络中的能量消耗,均衡了网络通信负载。