Research On Terminal Positioning Technology Based On NB-IoT

In the era of great development of informatization,the technical demand for the Internet of Things has skyrocketed,and the demand for location information services is one of the current hot spots.This paper combines Narrow Band Internet of Things(NB-IoT)with positioning algorithms to meet the service requirements of the Internet of Everything ecosystem.NB-IoT has a high degree of attention in positioning communication technology,due to its technical characteristics of low cost,low power consumption,wide coverage,and large connection.In order to address the limitations of current positioning accuracy and power consumption,this paper studies the terminal positioning algorithm suitable for NB-IoT technology.The main research of this paper includes three aspects:(1)This paper proposes the RSSI positioning algorithm supported by the reference terminal.In order to overcome the limitations of power consumption and accuracy,cloud computing is used to avoid the contradiction between the complexity and power consumption of terminal equipment;And based on the RSSI ranging model,this paper uses the characteristics of the large connection and wide coverage of the narrowband Internet of Things,and with the support of the reference terminal,uses the optimal strategy to select the relevant environmental parameters to make the ranging results more accurate.On the basis of using the least squares algorithm to obtain the target position,the algorithm proposed in this paper uses the constraint circle constructed by referring to the relevant information of the terminal to determine and correct the final estimated position.Compared with the general positioning algorithm based on signal strength,the proposed algorithm has significant accuracy by MATLAB software simulation.(2)In the positioning algorithm based on delay estimation,the delay estimation is affected by problems such as multipath effect,serial interference between base station cells,and low delay resolution,resulting in poor positioning accuracy.This paper proposes an improved frequency domain weighted correlation function interactive execution serial interference cancellation algorithm to suppress the multipath channel interference and the influence of neighboring base station cells on the signal,the local interpolation of the correlation function is used to improve the accuracy of the delay estimation.The algorithm performs cell search for each base station cell to screen out highquality signals participating in delay estimation,and ensures that the strongest path signal sent by the base station cell is the first path to reduce the impact of delay error on the accuracy of the entire TDOA positioning algorithm.And through MATLAB software simulation,this paper compares with other time delay estimation algorithms,it has certain advantages in detection probability and low time complexity.(3)In the positioning algorithm based on time difference of arrival,there are many nonlinear operations in the existing traditional TDOA positioning algorithm,the error is easy to be further transmitted,and most of the algorithms have a lack of rank matrix.In order to make the positioning model closer to the actual environment and improve the positioning accuracy And improve the robustness of the existing traditional positioning algorithm,take the site error into consideration and correct the error.Aiming at the influence of site error,an improved two-step weighted least squares algorithm based on site error elimination is proposed.Through MATLAB software simulation,compared with other TDOA positioning algorithms,it has obvious advantages,has strong anti-noise,and has a certain improvement effect on the positioning results.