Research On Key Technologies For Algorithm Accuracy Improvement Of Multi-domain Indoor Positioning System

With the development of information and wireless communication technology,positioning technology has become a widely used practical technology in all walks of life,such as Wi Fi,Wi MAX,Zig Bee,Ad hoc,Bluetooth and Ultra-Wide Band(UWB) are widely used in industrial production,warehousing and logistics,intelligent transportation,smart city,public security and justice,social correction,tourist attractions,hospital and medical treatment,which are closely related to the people.UWB positioning technology,with its transmission technology under extremely narrow pulse,has the advantages of low power consumption,good anti multipath effect,high security,low system complexity and high positioning accuracy,which is widely favored,and also reflects its good application future and prospect.Based on UWB locationing technology and radar signal sensing technology,this paper attempts to analyze the Time Domain(TD),Time of Arrival(TOA),Time Difference of Arrival(TDOA),Angle Domain(AD),Angle of Arrival(AOA),Direction of Arrival(DOA),Hybrid Domain(HD),mixed TOA / AOA,hardware assisted hybrid arrival,etc.A variety of improved algorithms are proposed to solve the problem of improving ranging accuracy and application in positioning system.It mainly focuses on the optimization and application design of typical algorithms such as time domain,angle domain and hybrid domain of UWB positioning technology,as well as the research on reducing error and realizing range positioning under the whole environment of LOS and NLOS.The main work of this paper is as follows:1.According to the basic knowledge of UWB,the basic principle of UWB positioning technology algorithm,the limitation of indoor positioning technology,the basic positioning technology,and the typical positioning and ranging algorithms in time domain,angle domain and mixed domain,such as TOA,TDOA,TOF,Chan algorithm,Taylor algorithm,DOA,AOA,hybrid algorithm,LOS and NLOS characteristics,etc.,are described.2.In order to solve the problem of improving the ranging accuracy and application in the positioning system,a variety of improved algorithms are proposed to optimize the typical algorithms in time domain.The Chan algorithm and BP neural network algorithm based on TDOA method are optimized respectively,and a two-step TOA estimation algorithm based on time inversion is proposed.In order to obtain better anti multipath effect ability,good adaptability and better estimation performance,so as to improve theindoor positioning accuracy of UWB,and achieve better results;based on TDOA,the UWB RF signal enhancement scheme and reference tag aided positioning method are used to overcome the multi-channel influence and defects of TDOA algorithm,and then the indoor positioning accuracy and shape of UWB are improved,and realizes the technical application.3.The typical algorithms in angle domain are optimized,and a variety of improved algorithms are proposed to solve the problem of improving ranging accuracy and application in positioning system.In this paper,we propose an angle domain method based on AOA estimation in UWB MIMO system is proposed to improve the spectrum efficiency and system performance.At the same time,multiple antennas can significantly improve the positioning accuracy;A decoupled covariance matrix optimization algorithm is proposed based on DOA estimation method.In radar signal processing technology,by expanding ACA matrix,UACA algorithm is proposed.A small-scale sparse matrix is designed to fill the loopholes in the difference common matrix generated by expansion operation.The decoupled covariance matrix is constructed by using mutual coupling matrix to obtain accurate DOA estimation.4.Based on the fusion of TDOA and AOA,a 3D joint TDOA / AOA fusion algorithm is proposed based on the fusion of TDOA method and AOA method,which improves the positioning accuracy effectively and realizes the application research in hybrid domain.