Research On WiFi Indoor Positioning Algorithm Based On ANM-SDP

With the popularization of the IEEE 802.11 standard,the coverage of wireless network in indoor environment is increasing year by year,which brings new explorable space-feature extraction based on WiFi signals to sense changes in indoor space,such as indoor personnel intrusion detection,breathing detection,heart rate detection and so on.The research of indoor positioning using WiFi signal has also become a hot topic in recent years.Some services based on indoor positioning have emerged as the times require,such as check-in systems in schools or companies,advertisements in shopping malls using public WiFi near shops,automated warehousing management services in warehouses and so on.In this paper,by studying the mobile communication technology,the principle of beamforming based on channel state information(CSI)measurement in MIMO-OFDM technology of WiFi communication is deeply analyzed,and the information of multipath channel in indoor environment is estimated based on the semi-definite programming(SDP)optimization problem in the framework of atomic norm minimization(ANM).The Toeplitz matrix u which is containing multipath information in the current enviroment can be obtained from CSI by ANM-SDP algorithm,and then we perform Vandermonde decomposition on this Toeplitz matrix u to obtain the estimation result of multipath ToF.The main work of this paper is to propose semi-positive definite programming algorithms based on ANM-SDP algorithm under single measurement vector(SMV)model,multiple measurement vector(MMV)model and weighted atomic norm(RAM)model.These three models have their own performance advantages and disadvantages when dealing with different demand scenarios.This paper will analyze the performance limits and parameter limitations of the three models from multiple dimensions.Firstly,a MATLAB simulation platform is built to simulate the Rayleigh fading channel transmission model in indoor scene with numerous obstacles.The corresponding observation vectors are obtained according to the preset normalized parameters such as channel bandwidth,multipath interval and head path propagation delay.The observation vectors obtained from the simulation channel transmission model are simulated and analyzed.Then three AP and one STA experimental scenario are arranged in the actual indoor environment,and the CSI data between STA and multi-AP in the real scenario are collected,and the measured performances of the three models are compared and analyzed.The WiFi indoor positioning technology,which is based on three models of ANM-SDP algorithm proposed in this paper,effectively solves the practical needs of different positioning accuracy in different real scenes,and the problems of high dependence on hardware,uncontrollable positioning accuracy and low positioning efficiency of traditional indoor positioning.