Research On Location Algorithm Based On Wi-Fi Backscatter Signal

With the development of the Internet of things,RFID positioning technology has the advantages of low power consumption,long operating distance,non-contact,small size and adaptability to complex environment,etc.,making it in an dominant position among many indoor positioning technologies.However,the current research on RFID positioning technology is mostly on the two-dimensional plane.With the increasing demand,the research on RFID 3D-space technology is urgent.Therefore,in this paper,from the two aspects of environmental backscatter technology and wireless signal propagation model,the 3D-LANDMARC positioning technology is improved to improve the accuracy of indoor positioning system,so that it can be applied in more indoor complex environments.First,in order to detect the backscatter signals in the environment,two detection methods are proposed.For one thing,By modeling and analyzing Wi-Fi backscatter system,the method uses the long training sequence and the short training sequence to obtain the channel state information so as to implement the detection function.For another,in order to further improve the quality of detection thresholds,an improved detection method using multiple antennas receiving Wi-Fi signals on Wi-Fi readers is proposed.Simulation results show that the proposed two detection methods can not only increase the detection distance and effectively detect backscatter signals in Wi-Fi environment,but also improve the stability of RSSI detection by Wi-Fi reader,which lays a foundation for the optimization of wireless signal propagation model.Second,introducing wireless channel modeling method based on ASGSO-BP.Equipped with better fitting performance data,the BP neural network build the wireless signal transmission under the current indoor environment path loss model,improving the estimation accuracy of signal transmission distance.The obtained model and RSSI received by the reader are used to calculate the distance,and the distance is used for LANDMARC indoor positioning system.Finally,Matlab platform was used to build a model for simulation verification.Experimental results show that the positioning performance of the proposed algorithm is improved significantly and meets the expected requirements.In the end,the backscatter detection technique is applied to 3D-LANDMARC,the LANDMARC algorithm Is optimized together with the ASGSO-BP line channelmodeling method,and the simulation experiment was carried out.Through the simulation experiment in Matlab environment,it can be proved that the algorithm proposed in this paper has improved the positioning accuracy and stability compared with the traditional positioning system,so it has certain application value.