Kaijie Xu 0001 Yinghui Quan Bowen Bie Mengdao Xing Weike Nie Hanyu E Fast Direction of Arrival Estimation for Uniform Circular Arrays With a Virtual Signal Subspace. 1731-1741 2021 57 IEEE Trans. Aerosp. Electron. Syst. 3 https://doi.org/10.1109/TAES.2021.3050667 db/journals/taes/taes57.html#XuQBXNE21