Granted Patent B2

US 7,359,520 · App. 10/214,350 · Granted Apr 15, 2008

Abstract

Claims (87)

1. A directional signal processing system for beamforming a plurality of information signals, said directional signal processing system comprising:

a plurality of microphones;

an analog-to-digital convertor for converting a plurality of said information signals from said microphones to a plurality of digital information signals;

an oversampled filterbank comprising at least one analysis filterbank for transforming said digital information signals in time domain into a plurality of channel signals in transform domain, and one synthesis filterbank, said oversampled filterbank being a weighted-overlap-add (WOLA) filterbank, said channel signal being a complex-valued, demodulated time-frequency signal;

a signal processor for processing the outputs of said analysis filterbank for beamforming said information signals, said synthesis filterbank transforming the outputs of said signal processor to a single digital information signal in time domain;

a post-filter provided between said signal processor and said synthesis filterbank;

a controller for controlling said post-filter; and

a digital-to-analog convertor for converting said single digital information signal to an analog information signal, and at least one of the following: a voice activity detector operably coupled to at least one of said signal processor and controller; a target-to-jammer ration estimator operably coupled to at least one of said signal processor and controller; a signal-to-noise ration estimator operably coupled to at least one of said signal processor and said controller; a combination matrix provided between said analog-to-digital converter and said analysis filterbank for pre-processing of said information signals in time domain; an active noise processor comprising a microphone and a loop filter.

2. A directional processing system as claimed in claim 1 , wherein said controller controls said post-filter based on the outputs of at least one of any of the following:

said voice activity detector;

said target-to-jammer ratio estimator;

said signal-to-noise ratio estimator.

3. A directional processing system as claimed in claim 1 , wherein said controller controls said post-filter based on the outputs of at least one of any of the following:

said voice activity detector;

said target-to-jammer ratio estimator;

said signal-to-noise ratio estimator.

4. A directional processing system as claimed in claim 1 , wherein said combination matrix is a FIR filter.

5. A directional processing system as claimed in claim 1 , wherein said combination matrix is a FIR filter.

6. A directional processing system as claimed in claim 1 , wherein said combination matrix is an IIR filter.

7. A directional processing system as claimed in claim 1 , wherein said combination matrix is an IIR filter.

8. A directional processing system as claimed in claim 1 , wherein said signal processor comprises:

at least one multiplier for multiplying the outputs of said analysis filterbank with at least one weight factor; and

at least one summation circuit for summing the outputs of said multiplier to form the channel signals.

9. A directional processing system as claimed in claim 1 , wherein said signal processor further comprises:

at least one multiplier for multiplying the outputs of said analysis filterbank with at least one weight factor; and

at least one summation circuit for summing the outputs of said multiplier to form the channel signals.

10. A directional processing system as claimed in claim 8 , wherein said signal processor further comprises an adaptive processor for adjusting said weight factor based on a feedback adaptive processing.

11. A directional processing system as claimed in claim 9 , wherein said signal processor further comprises an adaptive processor for adjusting said weight factor based on a feedback adaptive processing.

12. A directional processing system as claimed in claim 10 , wherein said adaptive processor adjusts said weight factor based on the outputs of at least one of any of the following:

a voice activity detector;

a target-to-jammer ratio estimator;

a signal-to-noise ratio estimator.

13. A directional processing system as claimed in claim 11 , wherein said adaptive processor adjusts said weight factor based on the outputs of at least one of any of the following:

said voice activity detector;

said target-to-jammer ratio estimator;

said signal-to-noise ratio estimator.

14. A directional processing system as claimed in claim 1 , wherein said signal processor comprises a module for maintaining a linear phase response for filtering the complex-valued, demodulated time-frequency signal.

15. A directional signal processing system for beamforming a plurality of information signals, said directional signal processing system comprising:

a plurality of microphones;

an analog-to-digital convertor for converting said information signals from said microphones to a plurality of digital information signals;

an oversampled filterbank comprising at least one analysis filterbank for transforming said digital information signals in time domain into a plurality of channel signals in transform domain, and one synthesis filterbank;

a signal processor for processing the outputs of said analysis filterbank for beamforming said information signals, said synthesis filterbank transforming the outputs of said signal processor to a single digital information signal in time domain;

a post-filter provided between said signal processor and said synthesis filterbank;

a controller for controlling said post-filter;

a digital-to-analog convertor for converting said single digital information signal to an analog information signal; and

at least one of the following:

a voice activity detector;

a target-to-jammer ratio estimator;

a signal-to-noise ratio estimator;

a combination matrix provided between said analog-to-digital convertor and said analysis filterbank for pre-processing of said information signals in time domain; and

an active noise processor comprising a microphone and a loop filter,

wherein said controller controls said post-filter based on the outputs of at least one of said voice activity detector, said target-to-jammer ratio estimator, and said signal-to-noise ratio estimator.

16. A directional processing system as claimed in claim 15 , wherein said transform domain is a frequency domain.

17. A directional signal processing system for beamforming a plurality of information signals, said directional signal processing system comprising:

a plurality of microphones;

an analog-to-digital convertor for converting said information signals from said microphones to a plurality of digital information signals;

an oversampled filterbank comprising at least one analysis filterbank for transforming said digital information signals in time domain into a plurality of channel signals in transform domain, and one synthesis filterbank;

a signal processor for processing the outputs of said analysis filterbank for beamforming said information signals, said synthesis filterbank transforming the outputs of said signal processor to a single digital information signal in time domain;

a post-filter provided between said signal processor and said synthesis filterbank;

a controller for controlling said post-filter;

a digital-to-analog convertor for converting said single digital information signal to an analog information signal; and

at least one of any of the following:

a voice activity detector;

a target-to-jammer ratio estimator;

a signal-to-noise ratio estimator;

a combination matrix provided between said analog-to-digital convertor and said analysis filterbank for pre-processing of said information signals in time domain; and

an active noise processor comprising a microphone and a loop filter, wherein said combination matrix is a FIR filter or an IIR filter, wherein said controller controls said post filter based on the outputs of at least one of said voice activity detector, said target-to-jammer ratio estimator, and said signal-to-noise ratio estimator.

18. A directional processing system as claimed in claim 17 , wherein said transform domain is a frequency domain.

19. A directional signal processing system for beamforming a plurality of information signals, said directional signal processing system comprising:

a plurality of microphones;

an analog-to-digital convertor for converting said information signals from said microphones to a plurality of digital information signals;

an oversampled filterbank comprising at least one analysis filterbank for transforming said digital information signals in time domain into a plurality of channel signals in transform domain, and one synthesis filterbank;

a signal processor for processing the outputs of said analysis filterbank for beamforming said information signals, said synthesis filterbank transforming the outputs of said signal processor to a single digital information signal in time domain;

a post-filter provided between said signal processor and said synthesis filterbank;

a controller for controlling said post-filter; and

a digital-to-analog convertor for converting said single digital information signal to an analog information signal,

wherein said signal processor comprises:

at least one multiplier for multiplying the outputs of said analysis filterbank with at least one weight factor;

at least one summation circuit for summing the outputs of said multiplier; and

an adaptive processor for adjusting said weight factor based on the output of at least one of a voice active detector, a target-to-jammer ratio estimator, and a signal-to-noise ratio estimator.

20. A directional processing system as claimed in claim 19 , further comprises at least one of any of the following:

said voice activity detector;

said target-to-jammer ratio estimator;

said signal-to-noise ratio estimator;

a combination matrix provided between said analog-to-digital convertor and said analysis filterbank for pre-processing of said information signals in time domain; and

an active noise processor comprising a microphone and a loop filter.

21. A directional processing system as claimed in claim 20 , wherein said transform domain is a frequency domain.

Assignments (8)