Forming beams with nulls directed at noise sources
First Claim
1. A method comprising:
- (a) identifying angles of acoustic sources from peaks in an amplitude envelope, wherein the amplitude envelope corresponds to an output of a virtual broadside scan on blocks of input signal samples, one block from each microphone in an array of microphones, wherein the microphones of the array are arranged on a circle, wherein the virtual broadside scan comprises scanning a virtual broadside array through a set of angles spanning the circle in order to generate said output, wherein the virtual broadside array operates on the blocks of input signal samples;
(b) for each of the source angles, operating on the input signal blocks with a directed beam pointed in the direction of the source angle to obtain a corresponding beam signal;
(c) classifying each source as speech or noise based on analysis of spectral characteristics of the corresponding beam signal, wherein said classifying results in one or more of the sources being classified as speech and one or more of the sources being classified as noise;
(d) generating parameters for a virtual beam, pointed at a first of the speech sources, and having one or more nulls pointed at least at a subset of the one or more noise sources;
(e) operating on the input signal blocks with the virtual beam to obtain an output signal;
(f) transmitting the output signal to one or more remote devices.
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Accused Products
Abstract
A communication system (e.g., a speakerphone) includes an array of microphones, a speaker, memory and a processor. The processor may perform a virtual broadside scan on the microphone array and analyze the resulting amplitude envelope to identify acoustic source angles. Each of the source angles may be further investigated with a directed beam (e.g., a hybrid superdirective/delay-and-sum beam) to obtain a corresponding beam signal. Each source may be classified as either intelligence or noise based on an analysis of the corresponding beam signal. The processor may design a virtual beam pointed at an intelligence source and having nulls directed at one or more of the noise sources. Thus, the virtual beam may be highly sensitive to the intelligence source and insensitive to the noise sources.
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Citations
18 Claims
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1. A method comprising:
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(a) identifying angles of acoustic sources from peaks in an amplitude envelope, wherein the amplitude envelope corresponds to an output of a virtual broadside scan on blocks of input signal samples, one block from each microphone in an array of microphones, wherein the microphones of the array are arranged on a circle, wherein the virtual broadside scan comprises scanning a virtual broadside array through a set of angles spanning the circle in order to generate said output, wherein the virtual broadside array operates on the blocks of input signal samples; (b) for each of the source angles, operating on the input signal blocks with a directed beam pointed in the direction of the source angle to obtain a corresponding beam signal; (c) classifying each source as speech or noise based on analysis of spectral characteristics of the corresponding beam signal, wherein said classifying results in one or more of the sources being classified as speech and one or more of the sources being classified as noise; (d) generating parameters for a virtual beam, pointed at a first of the speech sources, and having one or more nulls pointed at least at a subset of the one or more noise sources; (e) operating on the input signal blocks with the virtual beam to obtain an output signal; (f) transmitting the output signal to one or more remote devices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 15, 16)
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10. A computer readable memory medium configured to store program instructions, wherein the program instructions are executable to implement:
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(a) identifying angles of acoustic sources from peaks in an amplitude envelope, wherein the amplitude envelope corresponds to an output of a virtual broadside scan on blocks of input signal samples, one block from each microphone in an array of microphones, wherein the microphones of the array are arranged on a circle, wherein the virtual broadside scan comprises scanning a virtual broadside array through a set of angles spanning the circle in order to generate said output, wherein the virtual broadside array operates on the blocks of input signal samples; (b) for each of the source angles, operating on the input signal blocks with a directed beam pointed in the direction of the source angle to obtain a corresponding beam signal; (c) classifying each source as speech or noise based on analysis of spectral characteristics of the corresponding beam signal, wherein said classifying results in one or more of the sources being classified as speech and one or more of the sources being classified as noise; (d) generating parameters for one or more virtual beams so that each of the one or more virtual beams is pointed at a corresponding one of the speech sources and has one or more nulls pointed at least at a subset of the one or more noise sources; (e) operating on the input signal blocks with the one or more virtual beams to obtain corresponding output signals; (f) generating a resultant signal from the one or more output signals. - View Dependent Claims (11, 12, 13, 14)
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17. A system comprising:
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memory configured to store program instructions; a processor configured to read and execute the program instructions from the memory, wherein the program instructions are executable by the processor to implement; (a) identifying angles of acoustic sources from peaks in an amplitude envelope, wherein the amplitude envelope corresponds to an output of a virtual broadside scan on blocks of input signal samples, one block from each microphone in an array of microphones, wherein the microphones of the array are arranged on a circle, wherein the virtual broadside scan comprises scanning a virtual broadside array through a set of angles spanning the circle in order to generate said output, wherein the virtual broadside array operates on the blocks of input signal samples; (b) for each of the source angles, operating on the input signal blocks with a directed beam pointed in the direction of the source angle to obtain a corresponding beam signal; (c) classifying each source as speech or noise based on analysis of spectral characteristics of the corresponding beam signal, wherein said classifying results in one or more of the sources being classified as speech and one or more of the sources being classified as noise; (d) generating parameters for a virtual beam, pointed at a first of the speech sources, and having one or more nulls pointed at least at a subset of the one or more noise sources; (e) operating on the input signal blocks with the virtual beam to obtain an output signal; (f) transmitting the output signal to one or more remote devices. - View Dependent Claims (18)
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Specification