基于信号相位搜索的WSN节点定位算法

节点定位是无线传感器网络（wireless sensor network，WSN）研究的热点问题之一，基于信号相位信息与物理距离间的关系提出了基于信号相位搜索的WSN节点定位算法。该算法首先根据节点间信号相位信息，基于余弦相似性算法原理构建目标函数，将WSN节点定位问题转换为目标函数最优解搜索问题；然后基于质心定位算法原理确定搜索初始像素单元；最后利用梯度下降法替代逐像素单元的遍历搜索，在不影响定位精度情况下进一步提高定位效率，减小定位功耗。仿真实验结果表明，该算法的各项指标良好，适用于WSN的节点定位。

Localization algorithm by using signal phase searching method for wireless sensor network

Node self-localization is one of the hot research topics in WSN. According to the relationship between signal phase and physical distance, this paper proposed a localization algorithm by using signal phase searching method for WSN. According to the received signal phase between the anchor nodes and the unknown node, this algorithm set up an objective function based on cosine similarity, and transformed self-localization of an unknown node in WSN into that of searching the optimal solution of an objective function. Then, it determined the initial search pixel by centroid localization. To reduce the complexity, this paper used gradient descent method to avoid the time consuming procedure of pixel-by-pixel search method. At the end, it investigated the performance by using simulated data.