Method and system for blind separation of independent source signals

A method of producing a plurality of output signals (zp(k)), where p=1, . . . P, each said output signal zp(k) corresponding to one of a plurality of source signals (ap(k)), said method comprising the steps of:

• (a) receiving a plurality of input signals (yq(k)), where q=1, . . . Q, which is the result of a plurality of source signals (ap(k)) having passed through a transmission channel;
• (b) spatially prewhitening said plurality of input signals (yq(k)) to satisfy a prescribed orthogonality constraint and to generate a plurality of fist signals (y′q(k));
• (c) employing a filtering matrix (W(k)) supplied with said plurality of first signals (y′q(k)) to produce a plurality of recovered signals (zp(k));
• (d) updating said filtering matrix (W(k)) to W′(k+1) in response to said plurality of first signals (y′q(k)) and said plurality of recovered signals (zp(k));
• (e) projecting said updated filtering matrix to the closest unitary filtering matrix;
• (f) outputting said plurality of recovered signals as signal representations corresponding to said plurality of source signals (ap(k)) when said filtering matrix has converged;
• and
• (g) when said updated filtering matrix has not converged, employing said closest unitary matrix as a new filtering matrix W(k+1) in step (c) and repeating appropriate ones of steps (c) through (g) until such time that said filtering matrix has sufficiently converged.

A system for blind separation of a plurality of independent source signals comprising:

• a receiver which receives a plurality of input signals that is the result of a plurality of independent source signals that has passed through a transmission channel;
• a pre-whitener which spatially pre-whitens said plurality of input signals to satisfy a prescribed orthogonality constraint and to generate a plurality of first signals;
• a filtering matrix supplied with said plurality of first signals to produce a plurality of recovered signals;
• a signal processor, supplied with said plurality of first signals and said plurality of recovered signals, being adapted to update said filtering matrix and to project;
• said updated filtering matrix to the closest unitary filtering matrix;
• and
• a convergence detector which controls the signal processor such that the signal processor continues to process said plurality of first signals and said plurality of recovered signals until said filtering matrix sufficiently converges and said plurality of recovered signals is outputted as representations of said plurality of independent source signals, wherein said closest unitary matrix becomes a new current filtering matrix upon said plurality of first signals and said plurality of recovered signals being processed.

A system for producing a plurality of output signals (zp(k)), where p=1, . . . P, each said output signal zp(k) corresponding to one of a plurality of source signals (ap(k)), comprising;

• a receiver which receives a plurality of input signals (yq(k)), where q=1, . . . Q, which is the result of a plurality of source signals (ap(k)) having passed through a transmission channel;
• a pre-whitener that spatially pre-whitens said plurality of input signals (yq(k)) to satisfy a prescribed orthogonality constraint and to generate a plurality of first signals (y′q(k));
• a signal processor which applies a filtering matrix (W(k)) to said plurality of first signals (y′q(k)) to produce a plurality of recovered signals (zp(k)), utilizes said plurality of first signals (y′q(k)) and said plurality of recovered signals (zp(k)) to update said filtering matrix (W(k)) to W′(k+1), and projects said updated filtering matrix to the closest unitary filtering matrix;
• and
• a convergence detector which controls the signal processor such that the signal processor continues to process said plurality of first signals (y′q(k)) and plurality of recovered signals (zp(k)) until said filtering matrix is sufficiently converged and said plurality of recovered signals (zp(k)) is outputted as representations of said plurality of source signals (ap(k)), wherein said closest filtering matrix becomes a new current filtering matrix W(k+1) upon said plurality of first signals (y′q(k)) and said plurality of recovered signals (zq(k)) being processed.

A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for providing blind separation of a plurality of independent source signals, said method steps comprising:

• receiving a plurality of input signals which is the result of a plurality of independent source signals having passed through a transmission channel;
• spatially pre-whitening said plurality of input signals to satisfy a prescribed orthogonality constraint and to generate a plurality of first signals;
• employing a filtering matrix supplied with said plurality of first signals to produce a plurality of recovered signals;
• updating said filtering matrix in response to said plurality of first signals and said plurality of recovered signals;
• projecting said updated filtering matrix to the closest unitary filtering matrix;
• outputting said plurality of recovered signals as representations of said plurality of independent source signals when said filtering matrix has converged;
• and
• when said filtering matrix has not converged, employing said closest unitary filtering matrix as a new current filtering matrix in step (c) and continuing to input said plurality of input signals into said filtering matrix to obtain a plurality of recovered signals, utilizing said plurality of first signals and said plurality of recovered signals to update said filtering matrix, projecting said updated filtering matrix to the closest unitary filtering matrix, and outputting said plurality of recovered signals as representations of said plurality of independent source signals when said filtering matrix has converged.