Estimation of Angular Spreads and Mean Angles of Arrival for Multiple Incoherently-Distributed Noncircular Sources

In this paper, we propose a new method for the estimation of the angular parameters (i.e., central DOAs and angular spreads) of noncircular and incoherently distributed (ID) signals. Contrarily to state-of-the-art techniques, the new method exploits the additional information about the angular parameters that is carried in the unconjugated covariance matrix. Contrarily to noncircular signals, this matrix is identically zero for the circular case and, therefore, it is totally ignored by all existing techniques when directly applied to noncircular sources thereby leading to performance degradations. It will be seen that the new method outperforms the main classical estimators that are all developed for circular sources only and that its performance advantage is more prominent at low SNR values and/or for low DOA separations.