A new Cramer-Rao lower bound for TOA-based localization

In this paper, we derive the Cramer-Rao lower bound (CRLB) for the 2-dimensional (2D) time-of-arrival (TOA) based localization. Unlike previous work on the CRLB, we consider a more practical propagation channel and relate it to inter-node range estimate through a distance-dependent variance model. We demonstrate that this will impact the derivation of the Fisher information matrix (FIM), eventually leading to a CRLB different from the existing derivations. This new theoretical framework provides us with additional insights on the immediate impact of the geometric configuration of anchor nodes on the localization accuracy.