We investigate the information regularity and identifiability of the blind source separation (BSS) problem with constant modulus (CM) constraints on the sources. We establish for this problem the connection between the information regularity [existence of a finite Cramér-Rao bound (CRB)] and local identifiability. Sufficient and necessary conditions for local identifiability are derived. We also study the conditions under which unique (global) identifiability is guaranteed within the inherently unresolvable ambiguities on phase rotation and source permutation. Both sufficient and necessary conditions are obtained.
Bibliographical noteFunding Information:
Manuscript received August 7, 2003; revised April 12, 2004. This work was prepared through collaborative participation in the Communications and Networks Consortium sponsored by the U.S. Army Research Laboratory under the Collaborative Technology Alliance Program under Cooperative Agreement DAAD19-01-2-0011. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. Carlos H. Muravchik.
- Blind source separation (BSS)
- Constant modulus (CM)
- Cramér-Rao bound (CRB)
- Information regularity