The Research And Implementation Of Positioning Technology Based On Base Station Of Mobile Terminal

With the popularity of intelligent terminals, people can easily access to wireless multimedia services, and the demand for localization is also increasing. Therefore, GPS (Global Positioning System) has been widely used. However, due to the GPS can not be positioned in the indoor environment, which makes the research of positioning method of mobile terminal based on cellular network has great significance.The research background and the significance of selected topic of positioning method of cellular network are summarized firstly in this paper, and the development situation at home and abroad and the difficult points of positioning method of cellular network are introduced.In view of the problem that the positioning method of received signal strength is easy to be influenced by environment and other factors, a improved weighted positioning algorithm of cellular network is proposed in this paper.In view of the defect that RSSI (Received Signal Strength Indication) is easy to be influenced by NLOS (Non Line of Sight), multipath effects and other factors, the method of half correction is proposed in this paper, it makes the localization accuracy is improved. In order to improve the positioning accuracy further, same base station and isolated points must be eliminated before calculating the position of mobile terminal. Secondly, the weighted positioning algorithm based on strength of signal, the iterative weighted positioning algorithm and the positioning algorithm of double centroid are proposed in this paper.In the laboratory, including iterative weighted centroid positioning algorithm, the four kinds of positioning algorithm have been verified in three different episodes of time, including early morning, afternoon and evening, and they are analyzed and compared too. In terms of average positioning accuracy, the experiment result shows that the iterative weighted centroid positioning algorithm is about 240 meters, the iterative weighted algorithm is higher than other two kinds of algorithm which are proposed in this paper and they are all higher than the former, and they have achieved the average positioning accuracy of 240 meters and 150～800 meters based on base station which are provided by Baidu map and Tencent map, and the four kinds of positioning algorithm are all hardly influenced by time.The four kinds of positioning algorithm have been test in the same three episodes of time in some different real scenarios which are selected randomly, the result is consistent with the result of validation, and a base station positioning system is designed and implemented. The average positioning accuracy of this system is about 170 meters, and it has certain practical significance in some complex indoor environment which has no Wi-Fi (Wireless Fidelity). Lastly, many possible situations are considered in this system, this makes it has good robustness.