Research On RFID Based Indoor Location Algorithms

Currently RFID is a widely used technique in indoor location. Some related technology and algorithms using active tag for indoor location is studied in this paper. The RFID technology has the advantages such as contact-less, non-line-of-sight, multi-object recognition, long transmission range, scalability and promising cost effectiveness, so it has been regarded as a viable and popular candidate for indoor location sensing.Some related technology and algorithms using active tag for indoor location is studied in this paper. Based VIRE algorithm, we introduced a new model of indoor path loss of RF signal to calculate the RSSI of visual reference tags. Then the coordinate of the target can be got by the most nearby reference tags. Moreover, an improved location algorithm is proposed by the introduction of a correction mechanism called recursive-calibrate to reach a higher accuracy of location. Simulation are also shown here to prove that the accuracy of localization is improved. Several factors are discussed in this paper, such as: the location and number of readers and tags, the number of visual reference tags, the value of K and the times of recursive-calibrate.As location error will be increased by various factors in a more complex environment using accurate location algorithms, an area location algorithm is introduced to solve these problems: setting a dynamic threshold for each reader, calculate the current position of tracking tag, filter out of the impossible positions by area informations. And at last results and analysis obtained in the real environment is presented.