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Patents Held
 | United States Patents: |
| 1 |
6,577,966 |
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Optimal
ratio estimator for multisensor systems
A signal processing technique can be effectively used for source
separation, signal enhancement, and noise reduction when using a twin
microphone system. The class of stochastic signals for which
ratio-estimates can be computed from histograms is defined. This class
fits real-world signals of interest such as voice signals. Theoretical
computation in closed form of the optimal estimator for this class of
signals is disclosed. Two practical implementation solutions are
disclosed, as is a practical solution to exploit an echoic environment
model. Furthermore, two novel techniques for signal demixing are
presented. The application of the optimal estimator and the suboptimal
estimator to the case of more than two channels is disclosed.
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| 2 |
6,526,148 |
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Device
and method for demixing signal mixtures using fast blind source separation
technique based on delay and attenuation compensation, and for selecting
channels for the demixed signals
A delay and attenuation compensation-based BSS technique for source
selection and noise reduction is provided for speech recognition
applications. The undesired signals are attenuated in every situation and
from every direction as much as possible. For this purpose, the direction
of the input signals is determined. Depending on the direction of the
undesired signals, the internal delay between the microphones is
calculated. This internal delay is then used in subtracting the microphone
signals from each other. Therefore, the invention gives not only a good
directionality on average, but the best directionality for every listening
situation. Furthermore, the channel selection problem is solved in
conjunction with the BSS technique.
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| 3 |
6,343,268 |
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Estimator
of independent sources from degenerate mixtures
A system that reconstructs independent signals from degenerate mixtures
estimates independent Auto Regressive (AR) processes from their sum. The
system includes an identification system and an estimator. A mixture of
two signals is inputted into the system and through the identifying and
filtering processes, two estimates of the original signals are outputted.
The identification system includes an ARMA identifier, a computation of
autocovariance coefficients, an initializer and a gradient descent system.
The estimator includes filtering.
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