A NLOS localization algorithm based on constraint satisfaction optimization

Wireless localization has become an important issue in internet of things. However, the propagating signal from the mobile station to the base station usually encounters a variety of obstacles, resulting in the signal reflection and refraction, and therefore the non-line-of-sight (NLOS) path instead of the line-of-sight path (LOS). Generally, the NLOS error in the range measurement significantly affects the positioning accuracy. Thus, this paper investigates a novel localization algorithm based on the convex optimizations, where we exploit a constraint satisfaction optimization instead of the conventional objective optimizations. Moreover, we also discuss the validity issue of the constraints, and propose a controllable measurement error enlarging method to fully use the ranging information. The simulations have demonstrated the effectiveness of the proposed algorithm.