Error Analysis on RSS Range-Based Localization Based on General Log-Distance Path Loss Model

Received Signal Strength (RSS) is considered to be a promising measurement for indoor positioning. Many RSS range-based localization methods have been proposed due to the convenience and low cost of RSS measurements. However, a fundamental problem has not been answered, that is, how accurate are these methods? We think a key reason leading to this situation is the inappropriate assumption on RSS range models and measurement errors, which results in oversimplified analysis on those methods. In this paper, we use a more general range model and recognize the Generalized Least Square (GLS) method as an optimal estimator whose estimation error equals to the Cramer-Rao lower bound (CRLB). Through mathematical, techniques, we derive the analytic expression of the localization error for the GLS method, which reveals the key factors that affect the localization accuracy. Further studies on the minimal localization error disclose the proportional relationship between the localization accuracy and the above key factors.