Eigenvector analysis for separation of a spectrally concentrated source from a mixture.

An objective function is presented to recover a spectrally narrow band signal from multichannel measurements, as in electrocardiogram recordings of atrial fibrillation. The criterion can be efficiently maximized through the eigenvalue decomposition of some spectral correlation matrices of the whitened observations across appropriately chosen frequency bands. It is conjectured that the global optimum so attained recovers the source of interest when its spectral concentration around its modal frequency is maximal. Numerical experiments on synthetic data seem to support the validity of this hypothesis. Moreover, the components extracted from a patient data set with known atrial fibrillation show the characteristics of the associated f-wave as described in medical literature.