Cooperative sensor localization with NLOS mitigation using semidefinite programming

Cooperative time-of-arrival-based sensor localization in a non-line-of-sight (NLOS) environment is investigated. Cooperative sensor localization plays an important role in indoor networks where GPS is limited. However, indoor networks suffer from NLOS propagation which degrades localization accuracy significantly. In this paper, we assume that the estimator is able to discriminate NLOS connections from line-of-sight (LOS) connections. We introduce a novel semidefinite programming (SDP) approach for cooperative localization which exploits NLOS connections to enhance the accuracy of localization. The performance of the proposed algorithm is compared with that of the maximum likelihood estimator and previously considered algorithms. Computer simulations show the excellent performance of the proposed SDP approach.