Wireless Sensor Network Node Localization Algorithm Of Three-dimensional Non-ranging Study

As a supporting technique of Wireless Sensor Networks (WSN), node localization is the precondition of many WSN applications, such as target identification, surveillance and tracking. At present, most of the existing localization algorithms are designed for two-dimensional (2D), seldom for three-dimensional (3D) space. Based on the study of abundance related literatures, this thesis summarizes the basic concept and algorithm classification of WSN localization, and introduces several kinds of typical localization algorithms. An improved 3D DV-Hop algorithm and an improved 3D APIT algorithm are proposed based on the advantage of DV-Hop algorithm and APIT algorithm.First of all, by extending the localization thought of DV-Hop to 3D space, a 3D DV-Hop algorithm is proposed, then this thesis improves the 3D DV-Hop algorithm based on distributed design thought as it exists some defects when positioning. According to the simulation, it shows that the improved 3D DV-Hop algorithm can effectively increase the location accuracy, but it also increases the amount of calculation. After that, based on the APIT algorithm, this thesis puts forward a 3D APIT algorithm suitable for 3D space, and then it's improved due to the defects of testing error, low positioning ratio and large calculation. Compared with the original algorithm, the improved 3D APIT algorithm has higher location accuracy and positioning ratio with smaller calculation.At last, the improved 3D DV-Hop algorithm and the improved 3D APIT algorithm are compared under the same parameter, the simulation result shows that the two algorithms have different features, so they can be chosen according to different requirement. The two improved algorithm proposed in this paper can effectively ameliorate the performance of original algorithms, they have higher precision and proportion, so this paper provides basis for next step of thorough research and practical application.