Weighed Centroid Localization Algorithm Based On The RSSI For WSN

The Wireless Sensor networks have a wide applications with the rapidly development of Wireless Communication and Information Electronic and Computer Technology in recent years.WSNs has very important application value and research significance for the nodes localization with high positioning accuracy of to located and tracking target.The node localization technology is one of the most important support technology of WSN and have varieties location algorithm.This paper will study on the centroid localization algorithm,to solve the low localization accuracy and the anchor node optimization problems.Now more and more research under the three dimensional space of centriod localization algorithm has practical application function.The main research work as follows:(1)The improved algorithm of iterative weighted centroid algorithm.After analysis the centroid localization algorithm,this algorithm has thehigher positioning accuracy when the anchor node is high.However,in some practical applications,because the number of anchor nodes in the communication range may be less,in the network connectivity rate is lower,which will affect the subsequent positioning.Therefore,we first introduce the iterative idea in this paper.Using the unknown nodes that have been successfully positioned and upgrade it to beacon nodes to continue positioning.It is improve the average connectivity between nodes.Next combined the centroid localization algorithm and RSSI localization algorithm to improve the positioning accuracy,and an improved algorithm for iterative weighted centroid algorithm is proposed.By setting the RSSI threshold to judge the weight to reduce the iteration error accumulation and the last step is correct the coordinate error.(2)To analysis the the weighted centroid algorithm based on the RSSI,it is found the RSSI achieves a certain degree of positioning accuracy due to the improvement of the inaccurate weighting of the signal in the process of propagation.This papar proposed a threshold RSSI value to involved in the coordinate positioning correction.Firstly,find out all the anchor nodes in the communication radius of the RSSI are selected and the average the RSSI values.Sorted the RSSI and derived out the weighted.And simulation the three-dimensional coordinates and obtained the unknown nodes in the three-dimensional free space,so that can satisfy the practical application of the three-dimensional environment.By using matlab simulation software for simulation environment Settings to simulated above the two algorithms.The simulation results show that the improved algorithm of two positioning accuracy is better.It is more adapt to the complex environment and the three dimensional environment,and has better stability and adaptability.