Kalman Filtering of TOA Sequences and CWLS for Cellular Positioning

A method to mitigate the effects of non-line-of-sight (NLOS) errors in time-of-arrival (TOA) based cellular positioning is proposed. TOA readings are initially classified as LOS or NLOS and Kalman filtered for each base station (BS)-mobile station (MS) combination. After Kalman tracking the TOA/range sequences, range information for multiple BS's and one MS is converted to the MS's position information through a constrained weighted least squares technique (CWLS). Simulation results demonstrate the utility of the proposed algorithm.