...Toeplitz Matrix Reconstruction and Khatri–Rao Subspace
4.1. Khatri–Rao Processing Criterion Firstly, similar to the vectorization process in [28,29], the reconstructed covariance matrix of the array output shown in (8) can be rewritten as 𝐲𝑖≜vec{𝐑𝑌𝑖}=(𝐀̃∗⊙𝐀̃)𝐝𝑖+vec{𝜎2𝑛𝐈̃(𝑀+1),𝑖}yi≜...