Hybrid RSSD/AOA Cooperative Localization for 4G Wireless Networks with Uncooperative Emitters

This paper considers cooperative localization where the additional information from short-range communication among the mobile stations (MSs) in fourth generation (4G) cellular networks is used in the purpose of improving the localization accuracy. The problem of localization of MS in non-line-of-sight (NLOS) environment with uncooperative emitters is investigated. In our framework, a given MS must be localized, whose transmission is received on 2 base stations (BS) through AOA measurements and on a set of neighbor nodes (MS or anchors) with known positions through RSS (Radio Signal Strength) measurements. Uncooperative transmission implies that the MS transmission power is unknown. Our localization approach is then based on relative RSS measurements denoted as RSSD, combined with AOAs. For NLOS effect mitigation, we first use a selective aspect where only the best 4 RSS are considered. Second, a weighting procedure (in both range and angle) corrects at a certain level the effect of NLOS and allows its mitigation by reducing the set of possible locations of the MS. Using numerical results, we demonstrate the impact of (1) the proposed selective hybrid RSSD/AOA weighting strategy with uncooperative emitters on the accuracy of localization in mixed NLOS/LOS (line-of-sight) environment, (2) the cooperation between MS on the localization accuracy.