Research On Technologies Of Nodes Localization With Power Control For Wireless Sensor Networks

With the development of sensor technology and information networking, wireless sensor networks have tremendous utilization value in the area of industrial, agricultural, military, environment, and medical services. Identify the position where the specific event occurs or the location of a node that gather data is one of the most basic functions of wireless sensor networks, and some routing scheme, coverage information, load balance, and topology control are relay on the localizational information of sensor nodes in the networks. Therefore, the localization technologies in wireless sensor networks play an important role in the aspects of application, running, management, and so on. The research on the nodes localization technologies of wireless sensor networks has important theoretical and practical significance.In the wireless sensor networks, transmission power control may affect the topology of network, energy consumption and localization performance. In this thesis, two localization algorithms with power control for wireless sensor networks are proposed: One is Area Localization with Power Control (ALPC), another one is DV-Hop with Power Control (DHPC), which is an improved algorithm based on DV-Hop. The main research works are as below:(1) Introducing the architecture, features, applications and research situation of wireless sensor networks, and analyzing the basic principles and key technologies of localization in wireless sensor networks.(2) Proposing an algorithm of area localization with power control: First of all, introducing the principle of this algorithm and then using Mica2 sensor nodes in the actual environment experiment, discussing the effects of temporal and spatial on signal model, as well as how this affect changes the localization granularity according to the measured data. At last, Area Naming scheme is used to reduce network traffic loads and enhance the reliability of network.(3) Proposing a DV-Hop improved algorithm with power control: First, introduing the principle of DV-Hop, and then designing DHPC by improving DV-Hop, this algorithm improves the accuracy of estimated distance by power control, thereby improving the localization error.(4) Comparing and analyzing the characteristics of these two algorithms, the simulation results based on MATLAB platform show that ALPC algorithm can be very effective for locating every sensor node in several small areas in large-scale wireless sensor networks, the localization accuracy of DHPC algorithm is better than DV-Hop, and it can achieve very good accuracy in low-density networks, but the number of control packets of DHPC is more than DV-Hop.(5) Designing a localization system of wireless sensor networks, the experimental results show the localization system can achieve very good localization accuracy.