Localization Algorithm Based On Multidimensional Scaling In Wireless Sensor Networks

Wireless Sensor Networks (WSN) can be designed and developed because of development in sensor technology, Micro-Electro-Mechanism System (MEMS), modern network and wireless communication technology. It has been considered as one of the most important technologies in 21st century due to its bright future in application. More and more researchers focus on Wireless sensor network.Localization technology is one of the supporting technologies in WSNs. The localization algorithm based on the multidimensional scaling is a centralized algorithm. The algorithm constructs node distance matrix by calculating the shortest path distance between each pairs of nodes, and uses multidimensional scaling technology (MDS) to estimate the location of each node. The algorithm can be used when the measured distance of neighbor nodes is known or the connectivity information is only known. The algorithm need less anchors, and has not limitation with the place of anchors. It has better positioning accuracy in the uniformly-distributed network. When the network has non-uniform distribution, there are some errors between the shortest path and actual distance between nodes, and the positioning accuracy is reduced.In order to solve this problem, a novel localization algorithm assigning distances to the edges of connected graph according to local density is proposed. Under the condition of only the connectivity information of neighbor nodes being known, different coefficients are set based on different connectivity. And then the edges of neighbor nodes are assigned distances according to their connectivity and the corresponding coefficients. Consequently, the difference between the shortest paths distance and the real distance is reduced. The results of simulation show that the proposed algorithm reduces the average estimation errors and has better adaptability in non-uniformly distributed network.