Research On Indoor Location Sensing Technique And Implementation Base On RFID

RFID（Radio Frequency Identification）has been praised as one of the most promisingtechnologies in the21stcentury. It is a noncontact automatic identifying technology usingradio communication. With the rapid development of the wireless technology and the increaseof data service and multimedia service, the demand of navigation and positioning becomesmore and more strong. Highly accurate location information is needed to reallocate resources,improve efficiency and ensure public security, especially in some large indoor environment.Although widely used for outdoor location, GPS is still not capable of covering indoorenvironment. Due to various influence factors in indoor environment and the complexity ofsignal propagation characteristic, indoor location is one of the difficult topics of presentresearch. RFID technology is a cost-effective, reliable and practical method for indoorlocation.This paper presents a systematic research on indoor location technique and an indoorlocation system base on RFID technology. This system uses a PIC chip as the micro controlunit and CC1020radio chip and the peripheral circuit as the radio communication module.This paper describes the design process of the system architecture, function modules andsystem circuit in detail. In this system, the communication protocol of the RFID indoorlocation system has been implemented. An in-depth analysis of the coordination methodbetween readers, the communication mode the conditions transformation process betweenreaders and tags and tags anti-collision algorithm is presented in the paper.In addition, a novel indoor location algorithm is proposed, which utilizes thecharacteristic of active RFID tags to realize accurate location. The algorithm utilizes theconcept of node tags and the accuracy of the location can be improved significantly. Thetracking tags detects the node tags to find out the subarea location of the tracking tags andthen uses the algorithm based on received signal strength to locate the tracking tags.Compared with the LANDMARC algorithm, the experiment result shows that the proposedalgorithm can reduce the average and maximum error by37%and49%respectively and this system can reduce the location error efficiently, accommodate the dynamic environment andhas strong stability.