Image Number 12 for United States Patent #8144896.
A system that facilitates blind source separation in a distributed microphone meeting environment for improved teleconferencing. Input sensor (e.g., microphone) signals are transformed to the frequencydomain and independent component analysis is applied to compute estimates of frequencydomain processing matrices. Modified permutations of the processing matrices are obtained based upon a maximum magnitude based depermutation scheme. Estimates of the plurality of source signals are provided based upon the modified frequencydomain processing matrices and input sensor signals. Optionally, segments during which the set of active sources is a subset of the set of all sources can be exploited to compute more accurate estimates of frequencydomain mixing matrices. Source activity detection can be applied to determine which speaker(s), if any, are active. Thereafter, a least squares postprocessing of the frequencydomain independent components analysis outputs can be employed to adjust the estimates of the source signals based on source inactivity.
