Joint TDOA and FDOA Estimation: A Conditional Bound and Its Use for Optimally Weighted Localization

—Modern passive emitter-location systems are often based on joint estimation of the time-difference of arrival (TDOA) and frequency-difference of arrival (FDOA) of an unknown signal at two (or more) sensors. Classical derivation of the associated Cramér-Rao bound (CRB) relies on a stochastic, stationary Gaussian signal-model, leading to a diagonal Fisher information matrix with respect to the TDOA and FDOA. This diagonality implies that (under asymptotic conditions) the respective estimation errors are uncorrelated. However, for some specific (nonstationary, non-Gaussian) signals, especially chirp-like signals, these errors can be strongly correlated. In this work we derive a “conditional” (or a “signal-specific”) CRB, modeling the signal as a deterministic unknown. Given any particular signal, our CRB reflects the possible signal-induced correlation between the TDOA and FDOA estimates. In addition to its theoretical value, we show that the resulting CRB can be used for o...

• Type: Journal
• Year: 2011
• Where: TSP
• Authors: Arie Yeredor, Eyal Angel
• Keywords: Respective Estimation Errors, Stationary Gaussian Signal-model, TSP 2011, —Modern Passive Emitter-location