Comparison between innovative approaches of RFID based localization using fingerprinting techniques for outdoor and indoor environments

In this paper, two novel localization algorithms using a fingerprint technique are proposed. The performance evaluation of these algorithms is compared by calculating the location estimation error. The feasibility for indoor and outdoor applications is investigated. The Radio Frequency Identification (RFID) System is utilized by the reader being the localized target. The passive tags are chosen as reference tags. The basic principle of the fingerprint technique is to find the target location by comparing its signal (or information) pattern to a beforehand recorded database of known location data. Consequently, there are two main steps for estimating the target location: the detected tags, in the first place, discovered by the reader at each fingerprint location are stored in the database and called a fingerprint. The reader location, in the second place, can be estimated by using two proposed methods. The performance of each method is verified by experiment data. The best results of location estimation error among one another for outdoor environment is less than 38 cm and for indoor environment is less than 35 cm. Furthermore, the investigation found that proposed methods can be used in the real applications for both indoor and outdoor environment.