An Improved Indoor Wsn Localization Algorithm Based On Environmental-adaptive Parameters And Cooperative Communications

Wireless Sensor Network(WSN) is a self-organized multiple hops, which is composed of a large number of sensor nodes and deploys in monitoring area with the development of high-technology. WSN is widely applied for real-time monitoring, data collecting and monitoring objects in different environment. As the node location information is very important for target tracking, node monitoring, data acquisition, the localization technology has become one of the main supporting technologies in WSN. Compared with traditional wire- localization technology, the WSN technology can be easier to transplant and expand.This paper firstly introduces the background and development process of WSN technology, secondly introduces the indoor localization algorithms based on WSN. Nowadays localization technologies of WSN can be divided into two types. They are range- free and range-based technologies. This paper also introduces the basic algorithms of range-based and arithmetic of computing nodes’ coordinates.As real indoor environment is instable and the signal attenuation parameters depend on deployment environment, this paper proposed an APE(Adaptive-to-environment Parameter Estimation) method to achieve real-time parameters. APE method makes use of existing anchor nodes to communicate with each other to calculate the real- time environment parameters and use these real-time parameters to calculate the coordinates of unknown nodes. This paper also deeply studies APIT algorithm, analysis the drawbacks: In-To-Out error, large number of nodes cannot be localized when density of nodes is low. According to these drawbacks, this paper proposed a C AL(Coefficient-triangle APIT Localization) method to reduce the localization error and implement the cooperative communications to improve the localization coverage. The proposed CAL cooperative algorithm has been verified on MATLAB simulation system. Compared with traditional APIT algorithm, CAL cooperative algorithm has better performance on node localization error and coverage of target netwroks.