Research On Indoor WLAN 3D Localization Accuracy Bound And Access Point Selection Algorithm

With the increasing adoption of intelligent mobile devices,as well as the widespread deployment of Wireless Local Area Network(WLAN)infrastructures,users' demand for the efficient and accurate localization services is becoming stronger,which makes location based services and applications promising.Meanwhile,the indoor WLAN localization system which achieves the demanding positioning requirements has been an emerging research topic in recent years.Since the location signal could change significantly with multipath effect,shadow effect,and channel interference in indoor environment,the performance of indoor WLAN localization is affected by numerous factors.By analyzing the existing factors,we observe that the deployment of Access Point(AP)has significant impact on WLAN localization accuracy.Existing AP placement optimization mostly focuses on signal coverage,quality of service,network throughput,signal transmission speed,and the diversity of the signal etc.,which cannot describe the theoretical mathematical relationship between the WLAN positioning precision and AP localization.Thus,from the perspective of the mathematical relationship between WLAN positioning precision and the AP localization,this thesis aims to address the AP placement optimization problem.The main research work is as follows.Firstly,we introduce the fundamental principle of the indoor WLAN localization system with three measurements of the positioning signal respectively,namely angle of arrival,time of arrival,and received signal strength.Meanwhile,we analyze the fundamental principle of WLAN network optimization and WLAN indoor localization accuracy bound.Based on it,we discuss the correlation of the WLAN network optimization and the localization accuracy bound in WLAN.Secondly,due to the diversity of the indoor WLAN localization approaches and the complexity of the received signal,by using the fisher information matrix,we derive the localization accuracy bound in WLAN by selecting single,double,and three measurements,as well as analyze the WLAN localization accuracy bound under single and mixed signal distribution respectively.In order to better depict the real WLAN environment,we derive the three-dimensional localization accuracy bound of indoor WLAN to improve the availability of the proposed model.Finally,by combining the three-dimensional localization accuracy bound of indoor WLAN and the fundamental principle of WLAN network optimization,we construct the AP deployment optimization objective function for WLAN indoor localization.Meanwhile,we analyze the influence of key parameters on the WLAN indoor localization accuracy bound for the AP optimization model.And based on the AP optimization model,we finally obtain the optimal WLAN network scheme by using the simulated annealing algorithm.Furthermore,we conduct the extensive simulations and experiments to verify the effectiveness and feasibility of the designed AP optimization approach respectively.