Research On Localization Algorithm Based On TDOA In Multipath Environments

TDOA location technology has received more and more attention for its high positioning accuracy, low complexity algorithm, and it is easy to apply. The Core of TDOA location algorithm is TDOA delay estimation, however, due to multipath effects can cause TDOA delay estimation error increases, causing decrease positioning accuracy. Therefore, about multipath effects on location estimate, we propose a algorithm to reduce positioning errors.In this paper, we propose a TDOA location algorithm which based on the Garder timing synchronization, drawing ideological Garder timing errors in timing synchronization, we can take the TDOA delay to strike into solving the received signal of the reference point ?mk‘ and decimal bias ?uk‘. this method can accurately obtain TDOA delay value, the algorithm can improve the resolution of TDE, after obtaining TDOA delay,we can estimate the location coordinates of nodes by positioning algorithm. This method is applied to indoor TDOA localization experiments, in multipath environment is weak, the positioning error of about 0.14m; in multipath environments relatively strong, the positioning error of about 1.6m. As strong multipath environment the positioning error is strong too, which does not meet the indoor location accuracy requirements, therefore, in timing synchronization based on TDOA estimate, we take the improved Kalman filter algorithm to filter the TDOA distance value, the positioning error is reduced to around 0.7m.The proposed algorithm can effectively reduce the influence of multipath effects, and the algorithm is easy to implement, and can be applied to different environments i ndoor positioning system, there are some practical value.