A new trilateration method to mitigate the impact of some non-line-of-sight errors in TOA measurements for mobile localization

In this contribution, a new mobile station (MS) localization method is provided using time of arrival (TOA) measurements, in the UMTS-FDD downlink. Contrary to the usual trilateration algorithms, the proposed method takes into account possible large TOA error measurements caused by non-line-of-sight (NLOS) and near-far-effect (NFE). To this end, the new method measures the ´coherence´ between the TOA estimates and allows the mobile to select the three most reliable measures among the whole available TOA measurements. Realistic simulations show the accuracy improvement provided by the proposed algorithm over a simple trilateration.