Z. Xiong (ISMB), F. Sottile (ISMB), R. Garelloy (ISMB) and C. Pastone (ISMB)
2014 IEEE International Conference on Ultra-Wideband – ICUWB 2014, 01-03 September 2014.
Non-line-of-sight (NLoS) propagation of radio frequency (RF) signal has proven to be challenging for the localization of unknown nodes in wireless networks. In particular, the blockage of RF signal can heavily affect the accuracy of range measurements performed between nodes and in turn may cause the position estimation diverging. This paper analyzes the Cram´er-Rao lower bound (CRLB) of cooperative localization in presence of NLoS measurements and proposes a cooperative NLoS identification scheme as well as a cooperative positioning algorithm based on belief propagation. The proposed algorithm is fully distributed and does not need to know the state of NLoS range measurements. Simulation results show that the proposed algorithm is able to detect the state of each range measurement and improve positioning accuracy in several NLoS conditions.