Improvement And Application Of RFID Indoor Localization Algorithm Based On RSSI

With the development of wireless technology and Internet of things,the demand for positioning and navigation in people's production and life is becoming more and more intense.Location technology and service based on location information have become research hotspots at present.Radio frequency identification(RFID)technology has good prospects in indoor positioning,and many scholars study on the RFID-based localization method in many application fields from many aspects.Aiming at the problem of low accuracy and the expensive hardware of the traditional indoor positioning methods,this paper proposes an active RFID indoor location algorithm based on received signal strength indication(RSSI).Through the simulation experiment,the positioning accuracies of different calculation methods are compared,and several factors that influence the positioning accuracy are studied.Through the comparison of the existing indoor location algorithms,we choose the location algorithm based on RSSI ranging as the research focus,and take the active positioning as the way of implementation,study the active RFID indoor location algorithm based on RSSI.The characteristics of RFID signal propagation are analyzed,and the parameters of log distance path loss model are calculated.The characteristics of distance fitting error and its relationship with environment are analyzed.The error of the location algorithm based on RSSI is affected by the initial value,so it is improved by using the weighted iterative method.The RSSI determines the weight of the label,to increase the effect of the label closer to the target in the calculation,and the true value is approximated by multiple iterations.Through simulation experiments,we compare the accuracy and performance of different location algorithms,and study the influence of initial value,label grid size and distance model parameters on position accuracy.The experimental results show that the weighted iteration method corrects the error of distance fitting to the position estimation by weighting method,and eliminates the influence of initial value deviating from the real value on positioning by iterations,improves the positioning accuracy,and its performance is stable.This paper validates the necessity of predetermining the distance model parameters in the positioning area,and applies the weighted iteration method in the three-dimensional positioning.