A simple and robust techniques using biased Kalman Filter are proposed to smooth and mitigate the NLOS effect. First the raw TOA data is tested to identify NLOS conditions repeatedly. Then biased Kalman Filter is used to smooth NLOS TOA data. The processed TOAs are used for TDOA formulation and provided for location estimation. The further tracking can smooth the mobile trajectory though not improve the accuracy much. From the simulation it can be seen the techn...
