Inter-vehicle range smoothing for NLOS condition in the persistence of GPS outages

Cooperative collision warning, based on vehicle-to-vehicle radio communications and GPS systems, is one of the promising active safety applications that have attracted considerable research interest. In this paper, we address one of the functional key points of the cooperative collision warning application, which is an accurate estimation of the range data of neighboring vehicles during persistent GPS outages under both line-of-sight (LOS) and non-line-of-sight (NLOS) situations. This paper suggests smoothing and mitigating the NLOS for radiobased ranging measurements. Simulation results show that the biased Kalman filter gives accurate range estimations.