Time-frequency esprit for direction-of-arrival estimation of chirp signals

In this paper, we develop an ESPRIT-type algorithm for estimating the Directions-Of-Arrival (DOA's) of multiple chirp signals using Spatial Time-Frequency Distributions (STFD's). An averaged STFD matrix (or multiple averaged STFD matrices) are used instead of the covariance matrix to estimate the signal and noise subspaces. The proposed algorithm is shown to provide a significant performance improvement over the traditional ESPRIT algorithm for FM sources, specifically in situations with closely spaced sources and low Signal-to-Noise Ratios (SNR's). Simulation results are provided to illustrate the performance of the proposed approach in scenarios with multiple narrowband chirp sources.