RSS Based Method for Sensor Localization with Unknown Transmit Power and Uncertainty in Path Loss Exponent

Localization of a sensor in wireless sensor networks (WSNs) has now gained considerable attention. Since the transmit power and path loss exponent (PLE) are two critical parameters in received signal strength (RSS) localization technique, many RSS based location methods considering the case that both of the transmit power and PLE are unknown have been proposed in the literature. However, these methods require a search process, and cannot give a closed-form solution to sensor localization. In this paper, a novel RSS localization method with closed-form solution based on two-step weighted least squares estimator is proposed for the case with the unknown transmit power and uncertainty in PLE. Simulations show that the proposed method has the better performance than the least square method (LS). Moreover, simulation results also prove that the proposed method can reach the Cramer-Rao lower bound (CRLB).