Research Of RSSI Based Localization Method In Wireless Sensor Networks

Wireless sensor network (WSN) is a new IT technology which comes after the Internet and will give great contribution to the change of human life style. It takes advantage of several modern technology including sensors technology, embedded system, MEMS technology, and wireless telecommunication. The basic unit in WSN is sensor nodes, and how to take localization of the the sensor nodes has important significance. RSSI based range measurement technology is a meaningful implementation scheme. RSSI means Received Signal Strength Indication, it is a optional part on wireless transmit layer. We can get a range estimation through the strength of signal and the use the data to finish localization.In this dissertation, firstly introduced is the existed localization method by category and corresponding evaluation standard as well as influence factors. Then we build up a simulation environment to the RSSI based WSN system by Matlab to serves as a common platform for different algorithms. And in the simulation we can set different background and distribution mode for both anchor sensors and unknown sensors.Next, several advanced and new localization method is proposed with simulation and analysis. Range measurement based method includes weighted centroid method and RSSI value comparison method. None range measurement based method includes least square method, probability distribution based method and localization method which use probability distribution function's replacement function.At last, the dissertation provides a design scheme of the hardware platform.