Research Of Location-aware Method Based On RFID Technology

The rapid development of information technology promotes the great development of wireless sensor networks(WSN) and the Internet of Things(IoT), the development of the Internet of Things technology then makes Location-aware of this important study attracts the researchers’ unprecedented attention. Only after the object location information has been confirmed, can people put forward and implement reasonable decisions according to the collected data and the object location information, the data would be useless if it doesn’t contain the location information. There are some limitations in the Location-aware technical means, such as Ultrasonic technology, infrared technology, and Wireless LAN technology. But, because of some technical characteristics such as non-contact, non-line-of-sight, and the cost is low, the RFID(radio frequency identification) technology has occupied an important position in the Location-aware method.Location-aware method is the method of location acquisitions in simple terms. But there are some respective advantages and disadvantages, both in Range-based and Range-free methods. In order to solve these Location-aware problems, combained with the RFID technology, the following research has been done in this paper:Firstly, this paper analyzes the principles and applications of the RFID technology, then elaborates the three major categories of Location-aware methods based on RFID technology, which are Range-based, Range-free, and the method combined with Range-based and Range-free. Both node localization method based on Range-based and node localization method based on Range-free are expounded and compared respectively.Then, the paper introduces the conventional wireless signal transmission model based on the RFID technology, makes an experiment on actual distance model test that combined with the realistic environment, and then gets the specific loss model formula. Considering some factors in the specific environment could produce adverse effect on multipoint localization algorithm, this paper proposes a new k-weighted centroid algorithm reference adjacent beacon node to get RSSI ranging amendments. The simulation results show the effectiveness of this method which can amend the adverse effects of the environment.At last, this paper introduces the APIT algorithm based on Range-free and some algorithms that improved from APIT, points out their advantages and disadvantages. In considering of the algorithms that improved from APIT can not accurately achieve the estimation of the distance that based on RFID technology, a new kind of N-APIT algorithm that used adjacent beacon node as fixed beacon node is proposed, which can be dealt with the problem of RSSI ranging amendments, and then puts forward the improvement of N-APIT, which can improve network node coverage rate and deal with the extreme situation. In the end, the Matlab2012 b simulation environment is used to test the N-APIT algorithm’s performance, the results shows that under the range error of 5% and 10%, compared with traditional algorithms, N-APIT algorithm can reduce the average error by 3.15% and 12.59% respectively, and has achieved good results.