| 摘要 |
A method for mitigating non-line-of-sight (NLOS) effects in a localization system uses both multipath channel characteristics and information from the mobile network. The method iteratively estimates the first arriving path of the received signals and the terminal location, with the estimate of the terminal location improving the estimate of the first arriving path, and vice versa. Initially, a peak selection method (100) determines a rough time-of-arrival (TOA) for a signal received (101) at each of a number of different fixed terminals (FTs). An estimate of the location of the mobile unit is then provided (e.g., based on a least-squares (LS) triangulation) (200). If the residual error is unsatisfactory, the TOAs are refined, using a search-back algorithm (400), which searches back from the strongest paths of the received signals. The new TOAs are used to refine the estimate of the location of the mobile terminal. In addition, the parameters of the search-back algorithm (e.g., a search-back threshold) may be modified for greater accuracy in the estimated first path. The first arriving path estimate and the location estimate are iterated until convergence (e.g., the residuals are within a tolerance) or until a termination condition is reached, usually controlled by the thresholds setting (300). |
