A Hybrid Framework for Radio Localization in Broadband Wireless Systems

This paper presents a framework of hybrid models based on multilateral radio localization estimators that use the received signal strength (RSS), the time of arrival (TOA), the time difference of arrival (TDOA) and the angle of arrival (AOA) measurements of signals traveling from a mobile station (MS) to a set of base stations (BSs) in broadband wireless systems. The accuracy of hybrid localization is analyzed based on the Cramer-Rao lower bound, the Taylor-series approximation and the multi-step least square estimator. Explicit formulas that provide the link among RSS, TOA, TDOA or AOA methods is analytically explained. Numerical simulations show that a simple and efficient hybrid estimation scheme combining RSS, TOA, TDOA and AOA data achieves higher positioning precision than that of the RSS-only, the TOA-only, the TDOA-only or AOA-only methods.