Research On Ultra Wideband Location Technology Under NLOS Environment

Nowadays,the demand for positioning service is increasing,and the development of wireless positioning technology is becoming more and more fast.The advantages of the nanosecond non sinusoidal pulse based on the UWB positioning technology enter the people's field of vision.However,the actual location environment is not all the sight distance environment,so the location of target for NLOS environment has become a hot topic.Based on the analysis of the wireless location algorithm in the NLOS environment,this paper revise the UKF,realizing the positioning and tracking of the target,and provide the guiding significance for the research and design of wireless positioning system.Based on the theory of ultra wideband wireless communication,the characteristics of UWB signals and channels are analyzed,and the theory of positioning system is studied.Based on the UWB channel model C,several common positioning technologies are compared and analyzed.On the basis of TDOA/AOA hybrid distance measuring method,the method of solving three kinds of hyperbolic nonlinear equations is analyzed in order to solve the hyperbolic model of TDOA algorithm,and the performance of Taylor series expansion is used for the contrast performance.In the mobile communication environment,the additional delay of the NLOS signal is exponentially distributed.The update state is corrected in the update equation of the unscented Kalman filter,so that the error will not enter the next iteration equation.This improved algorithm avoids the divergence of the unscented Calman filter,and does not increase the computational complexity.It can be seen from the simulation experiment that the combination of the hybrid location algorithm and the improved UKF algorithm can better locate and track the unknown nodes in the NLOS environment.Compared with the traditional location algorithm,this method reduces the RMSE and the node location error,and improves the positioning accuracy.It shows that the improved algorithm can effectively improve the positioning accuracy by using the UWB Technology in the NLOS environment.