Research And Implementation Of Enhanced Indoor Localization Algorithm Based On RSSI

In recent years,indoor localization technologies such as WiFi technol-ogy,Bluetooth technology,ultra-wideband technology,etc.,have continuously emerged.Indoor localization technology has developed in a spurt,and a large number of indoor location-based services and applications have been derived.However,the complexity of the indoor environment itself also brings huge chal-lenges to the research and development of it.In an indoor environment,the propagation of wireless signals is easily affected by reflection,refraction,etc.,which causes a large attenuation of the signal,and brings a large error to the ranging and localization based on the strength of the wireless signal.Aiming at solving the problems of indoor localization and analyzing the source of lo-calization error,this thesis proposes an enhanced indoor localization algorithm based on RSSI.The research content of each part are as follows:(1)Research on enhanced indoor localization algorithm based on forward localizationIn a typical indoor forward localization system,a fixed anchor point trans-mits wireless signals,and a mobile terminal realizes the localization function by receiving multiple anchor point signals.In this type of system,this thesis proposes a method for selecting the anchor point deployment position.Tthe goal of the algorithm is to maximize the difference between the received signals of multiple receiving points in the area.By adjusting deployment positionof the anchor,the optimal anchor deployment plan is obtained in the current area.Then,in view of the influence of different attenuation factors on the distance measurement during RSSI ranging,this thesis proposes a parameter adjust-ment algorithm based on maximum likelihood estimation,which adjusts the parameters through multiple sets of observations to improve the ranging accu-racy.Finally,the trilateral localization and fingerprint localization algorithms are combined to optimize the localization results of the local area.At the same time,the simulation results verify the effectiveness of the proposed algorithms.(2)Research on Enhanced Indoor localization Algorithm Based on Fusion of reverse and forward localizationDifferent from the forward localization system,in the reverse localization system,the mobile terminal transmits wireless signals,and the pre-deployed fixed anchor node receives the signal and locates the mobile terminal.This article first proposes a parameter adjustment algorithm based on the minimum ranging error for the reverse localization system,which improves the ranging accuracy by dynamically adjusting the system model parameters.On this basis,this thesis further proposes forward and reverse localization fusion algorithms,via fusing the advantages of the two algorithms to improve the overall local-ization performance of the system.Finally,the effectiveness of the proposed algorithm is verified and analyzed through simulation results.(3)Design and Implementation of an Enhanced Indoor localization SystemAccording to the above-mentioned indoor localization enhanced algorithm research,this thesis designs and implements an enhanced indoor localization system with both forward and reverse localization.Based on the designed and completed enhanced indoor localization system,the algorithm designed in this thesis is actually tested and analyzed at the test site.Experimental results show that the enhanced indoor localization algorithm proposed in this thesis can achieve better localization accuracy in practice,and the algorithm meets the service requirements of indoor localization.