A cellular based mobile location tracking system

We propose a cellular-based location tracking system to make the best use of the range measurements and the supplementary information obtainable in cellular systems. The tracking system employs a Kalman filter for its flexibility in taking intermittent measurements and auxiliary information. Past location estimates and sector information are used to relax the minimum number of range measurements required, and therefore broaden the location coverage area. We analyze the probability of resolving the ambiguity when only two range measurements are available. A non-line-of-sight (NLOS) mitigation algorithm developed by Pi-Chun Chen (see IEEE WCNC, 1999) is used to improve erroneous location estimates corrupted by NLOS errors. The performance of the proposed cellular based location tracking system is evaluated through simulations.