Radu V Balan

US Patent:

6343268, Jan 29, 2002

Filed:

Dec 1, 1998

Appl. No.:

09/203115

Inventors:

Radu Balan - New York NY
Alexander Jourjine - Princeton NJ
Justinian Rosca - Monmouth Junction NJ

Assignee:

Siemens Corporation Research, Inc. - Princeton NJ

International Classification:

G10L 2102

US Classification:

704228, 704226, 704233, 381 941, 381 942, 706 22

Abstract:

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.

US Patent:

6577966, Jun 10, 2003

Filed:

Jun 21, 2001

Appl. No.:

09/886872

Inventors:

Radu Victor Balan - Levittown PA
Justinian Rosca - Princeton NJ

Assignee:

Siemens Corporate Research, Inc. - Princeton NJ

International Classification:

G06F 500

US Classification:

702 76, 702 77, 702 79, 702176, 702179

Abstract:

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.

US Patent:

6868365, Mar 15, 2005

Filed:

May 9, 2003

Appl. No.:

10/435206

Inventors:

Radu Victor Balan - Levittown PA, US
Justinian Rosca - Princeton NJ, US

Assignee:

Siemens Corporate Research, Inc. - Princeton NJ

International Classification:

G06F015/17

US Classification:

702180, 702177, 702179, 702183, 702197

Abstract:

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.

US Patent:

6901363, May 31, 2005

Filed:

Oct 18, 2001

Appl. No.:

09/982497

Inventors:

Radu Victor Balan - Levittown PA, US
Justinian Rosca - Princeton Junction NJ, US

Assignee:

Siemens Corporate Research, Inc. - Princeton NJ

International Classification:

G01L021/02
G01L011/02
H04B015/00

US Classification:

704226, 704233, 381 943, 381 947

Abstract:

Disclosed is a method of denoising signal mixtures so as to extract a signal of interest, the method comprising receiving a pair of signal mixtures, constructing a time-frequency representation of each mixture, constructing a pair of histograms, one for signal-of-interest segments, the other for non-signal-of-interest segments, combining said histograms to create a weighting matrix, rescaling each time-frequency component of each mixture using said weighting matrix, and resynthesizing the denoised signal from the reweighted time-frequency representations.

US Patent:

6952482, Oct 4, 2005

Filed:

Dec 5, 2001

Appl. No.:

10/007460

Inventors:

Radu Victor Balan - Levittown PA, US
Justinian Rosca - Princeton NJ, US

Assignee:

Siemens Corporation Research, Inc. - Princeton NJ

International Classification:

H04B015/00

US Classification:

381 941, 381 942, 381 92

Abstract:

Disclosed is an apparatus for and a method of filtering noise from a mixed sound signal to obtained a filtered target signal, comprising the steps of inputting the mixed signal through a pair of microphones into a first channel and a second channel, separately Fourier transforming each said mixed signal into the frequency domain, computing a signal short-time spectral amplitude |Ŝ| from said transformed signals, computing a signal short-time spectral complex exponential efrom said transformed signals, where arg(S) is the phase of the target signal in the frequency domain, computing said target signal S in the frequency domain from said spectral amplitude and said complex exponential.

US Patent:

7084801, Aug 1, 2006

Filed:

Jun 5, 2003

Appl. No.:

10/454917

Inventors:

Radu Victor Balan - West Windsor NJ, US
Justinian Rosca - Princeton NJ, US

Assignee:

Siemens Corporate Research, Inc. - Princeton NJ

International Classification:

H03M 1/12

US Classification:

341155, 381 92

Abstract:

An apparatus for estimating the direction of arrival (“DOA”) of a source signal includes microphones for transducing the source signal, amplifiers in signal communication with a corresponding one of the microphones, analog-to-digital converters in signal communication with a corresponding one of the amplifiers, and a digital processor in signal communication with the analog-to-digital converters for estimating the direction of arrival of the source signal; where a corresponding method for estimating the DOA of the source signal at one of several microphones includes estimating the measured signal spectral covariance matrix (“Rx”), and estimating the angle of the DOA responsive to the measured signal spectral covariance matrix.

US Patent:

7088831, Aug 8, 2006

Filed:

Dec 6, 2001

Appl. No.:

10/010255

Inventors:

Justinian Rosca - Princeton NJ, US
Ning Ping Fan - Plainsboro NJ, US
Radu Victor Balan - Levittown PA, US

Assignee:

Siemens Corporate Research, Inc. - Princeton NJ

International Classification:

H04R 3/00

US Classification:

381 92, 381 66, 702190

Abstract:

A system is provided for separating two audio channels recorded by an array of microphones. The system includes a calibration module for normalizing gain levels between a plurality of channels on each of a plurality of date frames, wherein each data frame is expressed in terms of time. The system further includes a delay parameter estimation module for accepting an output comprising the normalized channels, and estimating a delay parameter for a plurality of data frame sizes over a plurality of lag times, and sorting delays to generate corresponding source separated outputs.

US Patent:

7110944, Sep 19, 2006

Filed:

Jul 27, 2005

Appl. No.:

11/191105

Inventors:

Radu Victor Balan - Levittown PA, US
Justinian Rosca - Princeton NJ, US

Assignee:

Siemens Corporate Research, Inc. - Princeton NJ

International Classification:

G10L 21/02

US Classification:

704226, 704200

Abstract:

A method of filtering noise from a mixed sound signal to obtain a filtered target signal, includes inputting the mixed signal through a plurality of sensors into a plurality of channels, separately Fourier transforming each the mixed signal into the frequency domain, computing a signal short-time spectral amplitude |Ŝ| from the transformed signals, computing a signal short-time spectral complex exponential efrom said transformed signals, where arg(S) is the phase of the target signal in the frequency domain, computing said target signal S in the frequency domain from said spectral amplitude and said complex exponential, and computing a spectral power matrix and using the spectral power matrix to compute the spectral amplitude and the spectral complex exponential.