Blind separation of quasi-stationary sources: Exploiting convex geometry in covariance domain

Xiao Fu, Wing Kin Ma, Kejun Huang, Nicholas D. Sidiropoulos

Research output: Contribution to journalArticlepeer-review

78 Scopus citations


This paper revisits blind source separation of instantaneously mixed quasi-stationary sources (BSS-QSS), motivated by the observation that in certain applications (e.g., speech) there exist time frames during which only one source is active, or locally dominant. Combined with nonnegativity of source powers, this endows the problem with a nice convex geometry that enables elegant and efficient BSS solutions. Local dominance is tantamount to the so-called pure pixel/separability assumption in hyperspectral unmixing/nonnegative matrix factorization, respectively. Building on this link, a very simple algorithm called successive projection algorithm (SPA) is considered for estimating the mixing system in closed form. To complement SPA in the specific BSS-QSS context, an algebraic preprocessing procedure is proposed to suppress short-term source cross-correlation interference. The proposed procedure is simple, effective, and supported by theoretical analysis. Solutions based on volume minimization (VolMin) are also considered. By theoretical analysis, it is shown that VolMin guarantees perfect mixing system identifiability under an assumption more relaxed than (exact) local dominance-which means wider applicability in practice. Exploiting the specific structure of BSS-QSS, a fast VolMin algorithm is proposed for the overdetermined case. Careful simulations using real speech sources showcase the simplicity, efficiency, and accuracy of the proposed algorithms.

Original languageEnglish (US)
Article number7042785
Pages (from-to)2306-2320
Number of pages15
JournalIEEE Transactions on Signal Processing
Issue number9
StatePublished - May 1 2015

Bibliographical note

Publisher Copyright:
© 2015 IEEE.


  • Blind source separation
  • audio
  • identifiability
  • local dominance
  • pure-pixel
  • separability
  • speech
  • volume minimization


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