Hybrid RSS-TDOA Measurements Based Directional Target Localization in NLOS Environments

Localization constitutes the basic requirement of many applications in wireless sensor networks. Directional transmission has become very common with the development of electronic and antenna technologies. This paper aims to estimate both the position and transmission orientation of the directional target on the basis of combined received-signal-strength (RSS) and time-difference-of-arrival (TDOA) measurements in the non-line-of-sight (NLOS) environments. The localization problem is first formulized by the maximum likelihood estimation. Considering the problem is nonconvex, this paper then converts it into three relatively simple and intuitive sub-problems. Through converting them into generalized trust region subproblem (GTRS) and using bisection as well as multi-resolution search methods, the estimates is finally obtained. Simulation results show that the proposed method can estimate the orientation and position of the target effectively, its localization accuracy also outperforms the comparison methods significantly.