Precious Localization Based on Carrier Phase and Range Measurements in Wireless Networks.

In global navigation satellite system (GNSS), the pre-cise point positioning is widely used to reach precise localization performance. Inspired by this, we proposed a precise localization approach based on carrier phases and range measurements in wireless networks. In conventional localization approaches, the localization accuracy is limited by measurement errors of distances, angels and so on. Compare to those, the carrier phase has much more precise measurements which can achieve centimeter-level accuracy. At the same time, the ambiguity parameters of carrier phases are introduced by carrier phase measurements and the correctly fixed ambiguity parameters are the precondition of high localization accuracy. To address those issues, the parameters of localization and unfixed ambiguity are estimated by extended Kalman filter (EKF) at first. Then the LAMBAD approach is used to obtain the fixed ambiguity parameters. Moreover, to gain insight into the proposed localization approach, the Cramer-Rao lower bound (CRLB) is derived to assess the ultimate localization performance. Numerical results show that the proposed approach can achieve remarkable performance improvement in localization accuracy estimation and have lower CRLB compared to the conventional approach.