RSSI Positioning Algorithm In Wireless Sensor Network Based On Zigbee

Node positioning technolohy attracted increasing attention in the field of wireless sensor network technology. Wireless sensor network is widely used in daily life such as environmental monitoring, transportation managing, smart home, medical equipment and so on. Te sense the location of nodes is pretty critical in the applications above mentioned. To find out the location of nodes is a precondition for further work arrangement. At the same time, along with the technology development of sensor and wireless communication, Zigbee technology has been widely used because of its particular advantages. This thesis will study the node positioning technolohy according to the Zigbee technology.This thesis has made a simple introduction of them according to distance and pointed out the advantages and disadvantages of each algorithm. In lots of positioning algorithms on wireless sensor network technology,RSSI algorithm is a hot research and will be the main study point of this thesis because of its simple hardware structure, low cost and easy to be read by most wireless communication modules.So the paper were identified RSSI location algorithm using ZigBee technology research laboratory technology roadmap.This thesis analyzes the limitations of RSSI positioning algorithm and improves it at two stages-distance measurement and coordinate calculation. Gaussian filter module is introduced in the stage of distance measurement, therefore decreased the influence by small probability event that may alter the result a lot, and enhanced the accuracy of positioning information. In coordinate calculation stage, a new weight is introduced to replace the traditional weighted centroid algorithm, and optimizing nodes principle is used to choose better nodes to calculate. MATLAB simulation manifests that the positioning accuracy of improved algorithm is enhanced greatly.In order to verify the simulation results.seting up a wireless positioning platform in laboratory.The hardware platform consists of the following main components:computer、 gateway (network expansion board)、C51RF-3 emulator、ZigBee module (CC2430/CC2431)、battery plate、several USB wiring.Software development environment is IAR Embedded Workbench.Use to build a good experiment platform positioning experimental tests,the results obtained.By comparing results before and after the location algorithm improvements,The results obtained are consistent with simulation.Demonstrated improved RSSI location algorithm is effective and feasible.At last, apply RSSI positioning algorithm through real-time monitoring of ambient temperature.