Research On Quality Evaluation Method For Fingerprint Database Of Wi-Fi Positioning

Wi-Fi fingerprint positioning based on received signal strength(RSS)is an important research direction in the field of indoor positioning research.Researchers at home and abroad have carried out a series of researches on the construction of location fingerprint database,location fingerprint database update,positioning accuracy evaluation,and location fingerprint characteristics in Wi-Fi fingerprint positioning method.This paper focuses on two aspects of Wi-Fi fingerprint positioning method:location fingerprint database and positioning accuracy evaluation.Aiming at the problem of positioning accuracy evaluation,this paper proposed a new Wi-Fi indoor positioning accuracy evaluation method.Combining the Cramer-Rao lower bound(CRLB)with the wireless signal propagation model that considers the information of the wall,this paper proposed to predict and evaluate the Wi-Fi positioning accuracy in the indoor environment using the Cramer-Rao lower bound of the wireless signal propagation model that added to the wall.Simulation experiments verified that the proposed Wi-Fi indoor positioning accuracy evaluation method can more accurately evaluate the positioning accuracy of Wi-Fi positioning in indoor environments.And the proposed positioning accuracy evaluation method in this paper can also guide the actual deployment of Wi-Fi facilities.Aiming at the time-consuming and high-cost problem of location fingerprint database construction,in this paper we explore the use of the new Wi-Fi indoor positioning accuracy evaluation method to guide the offline collection and construction of location fingerprint database.Through experiments in typical practical scenarios,the actual positioning accuracy of Wi-Fi fingerprint positioning is used to investigate whether the actual positioning accuracy is consistent with the analysis result of the Wi-Fi indoor positioning accuracy evaluation method.The actual effective area of the evaluation method is also analyzed.Combining with the Wi-Fi fingerprint positioning results under different fingerprint acquisition densities,the changing characteristics between fingerprint collection density and positioning result is explored in different regions.The changing characteristics can help summarize the reasonable and efficient fingerprint collection scheme and reduce the construction cost of the location fingerprint database.