The Extended Invariance Principle Applied to Joint Time-Delay, Frequency, and DoA Estimation
This paper deals with the joint estimation of temporal (time-delay, Doppler frequency) and spatial (Direction-Of-Arrival, DOA) parameters of several replicas of a known signal in an unknown spatially correlated field. Unstructured and structured models have been proposed in the literature. The former suffers from severe performance degradation in some scenarios, whereas the latter involves huge complexity. It is shown how the EXtended Invariance Principle (EXIP) can be applied to obtain estimates with the quality of those of the structured model, but with the complexity of the unstructured one.