Research On CSI Localization Accuracy Bound For Indoor Moving Target

With the rapid development of wireless communication technology and portable communication equipments,the localization technology has deeped into all aspects of social life along with the applications of communication equipments,and people are enjoying the convenience brought by the localization technology all the time.Different from the outdoor environment,the signal is weakened due to obstructions such as buildings,furniture,and pedestrians in the indoor environment,so the Global Positioning System(GPS)cannot meet indoor localization needs.Compared with the Wi-Fi Received Signal Strength(RSS)commonly used for indoor localization,the Wi-Fi Channel State Information(CSI)contains more fine-grained physical layer information during signal transmission,so it can achieve higher indoor localization accuracy.Due to the lack of theoretical analysis of localization accuracy bounds in the existing the CSI-based localization methods,it is difficult to compare the ideal performance of different localization methods.Based on this,the specific works of this thesis are as follows:Firstly,the CSI-based indoor localization accuracy bound analysis method is proposed,which is based on the indoor signal propagation model to derive out the CSI-based localization accuracy bound using the theory of frequency domain localization accuracy by considering the relationship between the localization accuracy and the path loss,shadow fading,and multipath effect.And the difference between the actual localization error and the derived localization accuracy bound,and the influence of different factors on the localization accuracy are analyzed through experiments.The results show that the derived localization accuracy bound can precisely reflect the variation trend of the localization error.Secondly,the detailed theoretical derivation of the influence of asynchronous effects on the localization system is provided in this thesis.The signal propagation models under asynchronous effects are established by analyzing the influence of asynchronous effects on signal transmission and reception.By using the equivalent Fisher information matrix(EFIM),the CSI localization accuracy bounds under asynchronous effects are derived,and then,the effect of asynchronous effect on CSI localization is proved theoretically.Finally,in order to make up for the vacancy of the theory about CSI localization accuracy for moving target,a signal propagation model for moving target is established by using the geometric relationship of the signal transmission and reception between Access Point(AP)and moving target.Then,the CSI localization accuracy bound for moving target is derived,by combining the theory of localization accuracy in the frequency domain,and the influence of different experimental factors on the bound is analyzed.The experimental results show that the CSI localization accuracy bound for moving target can effectively describe the localization performance of moving target,and the practical application value of the CSI localization accuracy bound for moving target is verified by the accuracy bound networking optimization algorithm.