NLOS mobile location determination in CDMA cellular systems

grantor: University of TorontoWe consider mobile location determination in code division multiple access (CDMA) cellular systems using the time of arrival method. The objective of this thesis is to develop, new location determination algorithms to mitigate the effect of non-line-of-sight (NLOS) propagation. We consider the most critical condition (i.e. the mobile station (MS) is in NLOS with all base stations (BSs) and the MS is stationary). We propose new location determination algorithms based on the statistics of excess delay. Simulation results show that our methods reduce the position errors by about 50% relative to the classical constrained least squares method. Furthermore, we investigate the importance of a line-of-sight (LOS) range measurement by assuming the MS is in LOS with the closest BS and still in NLOS with the other BSs. Simulation results indicate that the position errors of our methods are reduced by more than 40% when one LOS range measurement is introduced.M.A.Sc