Research On TDOA Wireless Localization Algorithm Based On Wavelet Transform

Today, with the rapid development of wireless communication technology, wireless positioning technology to get people more concerned about how to provide the location information of a mobile terminal fast and accurate, real-time tracking of mobile terminals become our urgent request.Therefore, under different wireless communication environment, how to quickly and effectively get the location information of a mobile terminal has become a hot topic in the field of wireless communication technology issues.In the practical application of localization algorithm, due to the non-line-of-sight propagation environment, system to measure the positioning data tend to have a large amount of error, will affect the accuracy of wireless location algorithm. How to effectively eliminate the error caused by non-line-of-sight propagation quantity has become a focus problem in localization algorithm. In this article, we propose a solution using Wavelet Noise Reduction Theory to suppress the error caused by NLOS propagation.First introduced the theory of wavelet analysis, introduces the method of wavelet de-noising and steps, by analyzing the amount of model error caused by NLOS propagation theory validated the theoretical basis of wavelet noise reduction to eliminate measurement errors. The next concrete step wavelet noise correction for positioning data given, and gives the two positioning algorithm. One is a localization algorithm based on TDOA measurements, the other is a localization algorithm based on TDOA/AOA measurements. And they are all based on the measured value of the modified. Finally, in NLOS environment, assess the two positioning algorithm simulation results. Simulation results show that the algorithm can effectively realize the location of the mobile station is estimated, and the positioning performance is superior to other classic algorithms. It shows that the proposed method can effectively suppress the influence of NLOS error on the positioning algorithm performance, improve the positioning accuracy of the algorithm.With the widely application of the mobile positioning technology, people no longer limited to the requirements of the mobile station static positioning, dynamic tracking of mobile station has become the urgent request. Based on the above proposed positioning algorithm, this section gives two tracking algorithm. One is used the distance of related detection threshold, another is based on the Kalman filter tracking algorithm. From the simulation results point of view, the two algorithms can achieve tracking of the mobile station, good performance. In today’s commercialization of4G, OFDM technology has been more attention. This article in the OFDM system presents a localization algorithm based on wavelet transform. First, the use of multiple signal classification (MUSIC) algorithm to obtain the OFDM signal reaches the delay as a TOA value of the signal, and then calculated TDOA values. Use wavelet transform to correct the TDOA measurements and use the corrected measured values to achieve positioning algorithm, then achieved dynamic tracking of the mobile station. The algorithm simulation results show the good performance of the algorithm.Finally, the detailed summary is done for the whole text content, and the development of wireless location technology is prospected.