UWB positioning enhancement using Markov chain in indoor NLOS environment

The accuracy of the positioning system in indoor environment is often affected by none-line-of-sight（NLOS） propagation. In order to improve the positioning accuracy in indoor NLOS environment, a method used ultra-wide-band（UWB） technology, which based on time of arrival（TOA） principle, combining Markov chain and fingerprint matching was proposed. First, the TOA algorithm is used to locate the target tag. Then the Markov chain is used to identify if blocking happened and revise the position result. And the fingerprint matching is used to further improve the position accuracy. Finally, an experiment system was built to test the accuracy of the proposed method and the traditional Kalman filter method. The experimental results show that, compared with the traditional Kalman filter method, the proposed method can improve the positioning accuracy in indoor NLOS environment.