A NLOS mitigation method for CDMA2000 mobile location

In TDOA cellular mobile location, Non-Line-of-Sight (NLOS) propagation of radio waves brings about the larger errors of TOA/TDOA parameter measurements, thus resulting in location accuracy decreasing seriously. On the basis of TDOA errors analysis and NLOS characteristics investigation, a NLOS mitigation algorithm is proposed in this paper to realize the TDOA smoothing and LOS reconstruction by Kaiman filter in NLOS propagation environment, which effectively inhibits NLOS error of mobile location, so that positioning errors are reduced greatly. Simulation results show that the proposed algorithm can significantly improve the positioning accuracy and performance of TDOA mobile location under NLOS conditions. Combining with the WLS location resolving algorithm, the proposed algorithm can be well applied to mobile location of CDMA2000 cellular networks.