Deriving Ap Position And Antenna Orientation For Wi-Fi Indoor Localization And Passive Sensing

Wi-Fi is widely seemed as an important technical means for Internet access.However,researches in the past decade show that Wi-Fi can not only support wireless Internet access for users,but also realize indoor localization and human sensing.Channel state information(CSI)in a Wi-Fi signal can reflect both the amplitude and phase changes of the signal,where the signal arrival angle Ao A(Angle of Arrival)reflected by the phase information is combined with the antenna array orientation to achieve localization.In addition,the influence of the human body moving on the signal can be used for monitoring human sensing.For example,the combination of Doppler frequency shift of the signal and Ao A can be used to estimate the human trajectory,and the period of the amplitude change is used to monitor the human respiratory frequency.Localization technologies are basic element of the mobile Internet and the Internet of Things,which are penetrated into people's daily lives,such as intelligent navigation and logistics monitoring.In addition,as people's quality of life improves year by year,people also pay more attention to their health perceptions,such as breathing monitoring and trajectory tracking of elderly people living alone.However,most of the existing indoor localization and human sensing systems require professional and expensive equipment,making such systems not easy to popularize in daily life.Therefore,the popularity and ease of deployment of Wi-Fi are the promotion of indoor localization and sensing systems.The premise of achieving high-precision Wi-Fi indoor positioning and sensing is to accurately calibrate the position of the AP and the antenna array orientation,otherwise the accuracy is not high.Large-scale deployment of this system will consume a lot of time and labor calibration costs.Based on the key technical challenges of deployment and accuracy of indoor localization systems,this paper has developed the following solutions with the goals of low cost and high accuracy.The basic idea of the calibrationfree method is to use an algorithm instead of manpower,which can calculate the AP position and antenna array orientation,and then the calculated AP layout are used to achieve CSI indoor localization and sensing.Thus we can eliminate the manual calibration process.The main purpose is to achieve CSI localization and sensing without consuming a lot of labor costs to calibrate the AP position and antenna array orientation.Thus,we first propose a novel algorithm to automatically construct the AP layout and then localize mobile devices and realize passive sensing based on the constructed layout,which can cut down the deployment costs.Furthermore,we present an AP layout revision method to improve the accuracy of our system.Finally,we conduct experiments in different scenarios to verify proposed methods.