Generalized Esprit Algorithm Based on Schur-hadamard Product for Doa Estimation of General-rank Signals

A generalized directions-of-arrival (DOAs) estimation algorithm is developed for the rank-one (point source) and higher-rank (distributed source) signal models. For higher-rank signals, the integral steering vector is deduced to be a Schur-Hadamard product comprising the steering vector of rank-one source and a real matrix according to the symmetry assumption of angular signal intensity. And then a rotational eigenstructure is showed to exist accurately for two identical closely spaced subarrays. So DOAs are estimated using ESPRIT. The proposed algorithm needs little prior knowledge about angular signal intensity and can be used for sources with different angular signal intensity. Numerical results demonstrated its excellent performance versus SNR, snapshots and angular spread.