Speaker: Arie Yeredor (Tel-Aviv University)
Title: Identify, then Sparsify: Blind Separation of Superimposed Sparsely-Driven Auto-Regressive Processes
We address the blind separation of two autoregressive (AR) processes from a single mixture thereof, when their respective driving-noise ("innovation") sequences are known to be temporally sparse. Unlike other single-channel separation schemes, preceded by a dictionary-learning stage which specifies the sparsifying transformation(s), our method essentially estimates the sparsifying transformation of each source directly from the observed mixture (by estimating the respective AR parameters), and therefore does not require a training stage.
We cast the problem as a constrained, non-convex $\ell_1$ norm minimization and propose an iterative solution scheme, which iterates between linear-programming-based estimation of the respective driving-sequences given estimates of the AR parameters, and gradient-based refinement of the estimated AR parameters given the estimated driving sequences. Near-perfect separation is demonstrated in simulation.
Arie Yeredor received the B.Sc. (summa cum laude) and Ph.D. degrees in electrical engineering from Tel-Aviv University (TAU), Tel-Aviv, Israel, in 1984 and 1997, respectively. He is currently an associate professor with the School of Electrical Engineering, Department of Electrical Engineering — Systems, TAU, where his research and teaching areas are in statistical and digital signal processing. He also holds a consulting position with NICE Systems, Inc., Ra’anana, Israel, in the fields of speech and audio processing, video processing, and emitter location algorithms. Prof. Yeredor has served as an associate editor for the IEEE Signal Processing Letters, the IEEE Transactions on Circuits and Systems—Part II, and the IEEE Transactions on Signal Processing. He recently served as guest editor of a special issue of the IEEE Signal Processing Magazine on Source Separation and Applications – Recent Advances. He also served as general co-chair of The Tenth International Conference on Latent Variables Analysis and Signal Separation (LVA/ICA2012). He has been awarded the yearly Best Lecturer of the Faculty of Engineering Award (at TAU) six times. He served as a member of the IEEE Signal Processing Society’s Signal Processing Theory and Methods (SPTM) Technical Committee in 2005-2010, and currently serves as chair of the Signal Processing chapter of IEEE Israel Section.