Research On Wi-Fi Indoor Location Technology Based On RSSI Ranging Model

With the rapid development of location service market,people have higher and higher requirements for location technology.Especially,most of people's activities take place in indoor environment,so indoor positioning technology becomes very important.Wireless Fidelity(Wi-Fi)positioning technology based on Received Signal Strength Indicator(RSSI)ranging model has become a hot topic in indoor positioning research in recent years because of its simple detection mechanism,wide coverage,low hardware cost and easy implementation.However,the propagation of indoor wireless signal is vulnerable to various interferences,which affect the accuracy of location.Therefore,in order to improve the indoor positioning accuracy,the main work of this paper includes two aspects:(1)In view of the lack of systematic quantitative research on the factors affecting the indoor RSSI characteristics,this paper uses statistical analysis method and Matlab tool function to deduce through a large number of measured data in four aspects: the influence of receiving terminal orientation on RSSI,the influence of receiving terminal wireless card type on RSSI,the influence of different measurement time on RSSI and the influence of transmitting and receiving antenna height difference on RSSI from the perspective of indoor positioning.We measure and analyze the indoor statistical distribution characteristics of RSSI signals in a more comprehensive and complete way,so as to provide a deep understanding of the mechanism behind the indoor positioning technology based on RSSI ranging model,and lay a foundation for reducing signal interference and obtaining a more accurate indoor positioning model for real environment.(2)In order to build a propagation model(also called RSSI ranging model)with high accuracy to reduce the ranging error and improve the positioning accuracy,this paper improves the logarithmic distance path loss model based on the parameter correction,and proposes a model based on the distance residual correction,which introduces the distance residual correction equation on the basis of the original model.Data collection is carried out in real environment,and the proposed model is compared with the original model and the current common model based on polynomial fitting.The experimental results show that the model proposed in this paper improves the ranging accuracy by 58% and 51% respectively.At the same time,the positioning experiments show that the positioning accuracy is improved by 69% and 80% respectively.