A DOA Estimation Method With Kronecker Subspace for Coherent Signals

We propose a direction-of-arrival estimation method using the Kronecker subspace that can cope with coherent source signals. The proposed method employs a new formulation of the Khatri–Rao product array processing, where not only auto-correlations but also cross-correlations of source signals are regarded as virtual source signals transmitted to the difference co-array of the original sensor array, and can cope with up to
$N-1$
coherent signals with a sensor array having
$N$
sensors if the source signals have quasi-stationarity. Computer simulation results illustrate the performance of the proposed approach in comparison with that of conventional algorithms.