A Geometric Blind Source Separation Method Based on Facet Component Analysis
This work addresses blind source separation for researchers in signal processing, offering an incremental improvement over vertex-based methods by focusing on facet identification.
The authors tackled the problem of blind source separation for nonnegative linear mixtures by introducing facet component analysis (FCA), which identifies facets of the underlying cone structure in data, and demonstrated its effectiveness on nuclear magnetic resonance spectroscopic data.
Given a set of mixtures, blind source separation attempts to retrieve the source signals without or with very little information of the the mixing process. We present a geometric approach for blind separation of nonnegative linear mixtures termed {\em facet component analysis} (FCA). The approach is based on facet identification of the underlying cone structure of the data. Earlier works focus on recovering the cone by locating its vertices (vertex component analysis or VCA) based on a mutual sparsity condition which requires each source signal to possess a stand-alone peak in its spectrum. We formulate alternative conditions so that enough data points fall on the facets of a cone instead of accumulating around the vertices. To find a regime of unique solvability, we make use of both geometric and density properties of the data points, and develop an efficient facet identification method by combining data classification and linear regression. For noisy data, we show that denoising methods may be employed, such as the total variation technique in imaging processing, and principle component analysis. We show computational results on nuclear magnetic resonance spectroscopic data to substantiate our method.