RSS-Based Location Estimation with Unknown Pathloss Model

Recently, received signal strength (RSS)-based location estimation technique has been proposed as a low-cost, low-complexity solution for many novel location-aware applications. In the existing studies, radio propagation pathloss model is assumed known a priori, which is an oversimplification in many application scenarios. In this paper we present a detailed study on the RSS-based joint estimation of unknown location coordinates and distance-power gradient, a parameter of pathloss model. A nonlinear least-square estimator is presented and the performance of the algorithm is studied based on CRB and various simulation results. From simulation results it is shown that the proposed joint estimator is especially useful for location estimation in unknown or changing environments