Research On Node Localization Optimized Based On RSSI In Wireless Sensor Networks

With the development of Wireless Sensor Networks(WSNs) technology and application, the node location technology which one of the foundations of WSNs is received widely attention and research. Sensor node location technology is the support technology of most WSNs technology and application. So the research of node location is necessary.This paper introduces the wireless sensor networks location technology research situation at home and abroad, expounds the wireless sensor networks positioning system composition, and make a derailed description of the localization algorithm and preformance evaluation standard. Then, it introduces some existing localization algorithm based on range-based and range-free. In according the preformance evaluation standard, compares their advantages and disadvantages. This paper carried out the research based on Received Signal Strength Indicator(RSSI). A new optimization ranging algorithm was proposed to improve the ranging accuracy to achieve an improvement in positioning accuracy. The main research contents are as follows:(1)In the practical application, the RSSI ranging signal will be affected by the diffraction、refraction. The ranging data may produce shake and peak value. It can cause huge error to the position results. In this paper, we collect a large number of experimental datas to establish the relationship between distance and RSSI value.(2)In the different distance, we make a lot of experiments. And using the least square fitting method to get and analyse the RSSI-d curve.(3)In the campus environment, he ranging signal will be affected by the moving vehicle and pedestrian. Then, the anchor node selection strategy and dynamic optimization model has been proposed to reduce the ranging error for increasing the ranging precise. The experiments on actual outdoor environments show that the proposed scheme provides a higher accuracy as common location.(4)In this paper, the positioning system platform based RSSI were designed and implemented. The system includes upper position machine software and lower machine program. The experiments including the ranging Data collection and analyse. We calculate the target node coordinates using trilateration algorithm. The simulation experiments compare the traditional trilateration localization method and anchor selection strategy and dynamic optimization model proposed in this paper. The simulation results show that the proposed scheme can real increase the location accuracy.