EUROSPEECH '95
Fourth European Conference on Speech Communication and Technology

Madrid, Spain
September 18-21, 1995

Shift-Invariant Adaptive Local Trigonometric Decomposition

Israel Cohen, Shalom Raz, David Malah

Department of Electrical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa, Israel

A general formulation of shift-invariant "best-basis" expansions is presented. Specifically, we construct an extended library of smooth local trigonometric bases, and introduce a suitable "best-basis" search algorithm. We prove that the resultant decomposition is shift-invariant, orthonormal and characterized by a reduced information cost. The shift-invariance is derived from an adaptive relative shift of expansions in distinct resolution levels. We show that at any resolution level it suffices to examine and select one of two relative shift options - a zero shift or a 2-l-1 shift. A variable folding operator, whose polarity is locally adapted to the parity properties of the signal, extra enhances the representation.

Full Paper

Bibliographic reference.  Cohen, Israel / Raz, Shalom / Malah, David (1995): "Shift-invariant adaptive local trigonometric decomposition", In EUROSPEECH-1995, 247-250.