Research On Localization Algorithms For Wireless Sensor Networks

Wireless sensor networks is one of intelligent information network system, which is integrated information collection, information processing and transmission. This information system is capable of real-time perceiving and collecting environmental data and target information, can achieve communications and information exchanges between people and the physical world. Wireless sensor networks can be widely used in military and national defense, environmental monitoring, forest fireproofing, medical care and so on, has broad application prospect, play very important role for the development of information technology, economy and society.The node localization is the basis and key technologies for wireless sensor network. In many wireless sensor network applications, sensor nodes can determine the exact location of collected date if only know its own location, and provide useful monitoring service to users. The target information with no node position is always not any application value. Because locating information of nodes is important for all applications, so the study of localization algorithm becomes one hotspot in wireless sensor networks.First of all the thesis reviews the localization problem in wireless sensor networks, introduces the fundamental principles of self-localization techniques, discusses the evaluation criterion of the performance and the taxonomy of wireless sensor network self-localization algorithms, and then discusses the principles and characteristics of some representative localization approaches.This paper makes an intensive study DV-Hop algorithm. Analyse the principles, the reasons of error and simulation results of DV-Hop algorithm. as a result of the shortage of localization accuracy, the three improvement schemes are proposed. By increasing the number of anchor nodes, reducing the estimated average hop-size error and leading into2-D hyperbolic location algorithm, we will get the estimated position will be much closer to its real position. The main advantages of improved DV-Hop algorithm is decreased the position error greatly. Simulation results demonstrate that the performance of improved algorithm is too better than orginal DV-Hop algorithm and improve sensor node position accuracy effectively.