无线传感器网络中基于RSSI差值的改进定位算法

An Improved Localization Algorithm Based on RSSI-margin in WSN

无线传感器网络(WSN)的许多应用都需要知道节点的位置,在某些环境下还需要获得节点的相对位置.本文以WSN的特点为基础,首先介绍了接收信号强度的理论知识,进而提出一种优化的基于测距的定位算法:在应用中的多用户情况下,节点采用多跳方式进行通信,在信标节点冗余的情况下,针对不同信标节点位置范围,建立定位误差最小的相应信标节点库,继而对不同位置范围的待测节点优化选取其定位采用的信标节点,最后将由未知节点接收到的信号强度得到的多用户间的距离进行差值,优化求解非线性方程组,提高算法性能.仿真结果表明,本文中的RSSI WSN差值定位算法比传统的RSSI定位算法拥有更好的定位性能.

The position information of the nodes plays a more and more important role in wireless sensor network（WSN）. Based on the characteristic of WSN,this paper introduced the basic theory of RSSI and then suggested an improved range-based localization algorithm. Firstly,each anchor node was treated as target nodes separately. They all had different anchor nodes choice to keep smaller error. We got the number collection of anchor nodes corresponding to every anchor nodes. When localization really began,target nodes found the anchor node which has the strongest RSSI. Then it chose the suitable anchor nodes from the collection and estimated the distance to these anchor nodes by the Path-Loss model. Especially,this algorithm took the margin of the distances and solved the non- linear equation. Chan solution was chosen specially to improve the accuracy. The simulation result indicated that this localization algorithm had better performance than classical RSSI algorithm.