Multi-Channel Factor Analysis with Common and Unique Factors

TitleMulti-Channel Factor Analysis with Common and Unique Factors
Publication TypeJournal Article
Year of Publication2020
AuthorsRamírez, D., I. Santamaría, L. L. Scharf, and S. Van Vaerenbergh
JournalIEEE Transactions on Signal Processing
Volume68
Issue1
Pagination113-126
ISSN1053-587X
AbstractThis work presents a generalization of classical factor analysis (FA). Each of M channels carries measurements that share factors with all other channels, but also contains factors that are unique to the channel. Furthermore, each channel carries an additive noise whose covariance is diagonal, as is usual in factor analysis, but is otherwise unknown. This leads to a problem of multi-channel factor analysis with a specially structured covariance model consisting of shared low-rank components, unique low-rank components, and diagonal components. Under a multivariate normal model for the factors and the noises, a maximum likelihood (ML) method is presented for identifying the covariance model, thereby recovering the loading matrices and factors for the shared and unique components in each of the M multiple-input multiple-output (MIMO) channels. The method consists of a three-step cyclic alternating optimization, which can be framed as a block minorization-maximization (BMM) algorithm. Interestingly, the three steps have closed-form solutions and the convergence of the algorithm to a stationary point is ensured. Numerical results demonstrate the performance of the proposed algorithm and its application to passive radar.
DOI10.1109/TSP.2019.2955829
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