Patent ID: 9172479
Filing Date: 2015-10-27
Classification: H04B,H04H

Abstract:
1. A processing unit for processing a multi-channel audio signal, comprising: a delay element configured to delay an FM sum signal representing a sum of a first and a second audio signal; a converter configured to convert an FM difference signal representing a difference between the first and second audio signals to frequency domain, and configured to convert a noise signal representing noise in the FM difference signal to the frequency domain; a frequency-based noise suppression unit configured to suppress noise in the difference signal to derive a de-noised frequency-domain difference signal based on a gain function based at least on an amplitude of the frequency-domain noise signal, wherein the gain function is limited to a maximal and a minimal value; an inverse transform unit configured to inversely transform the de-noised frequency-domain difference signal or a signal derived from the de-noised frequency-domain difference signal to time domain; and a de-matrixing unit configured to compute the first and second audio signals from the delayed FM sum signal and time domain difference signal; and further comprising a gain unit configured to apply additional gain factors to the de-noised frequency-domain difference signal to derive a processed frequency-domain difference signal, wherein the inverse transform unit is configured to inversely transform the processed frequency-domain difference signal.