Adaptive beamformer using a log domain optimization criterion
First Claim
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1. In a computing environment, a method comprising:
- receiving input signals from a plurality of microphones at an adaptive beamformer and a time invariant beamformer, the adaptive beamformer including an adaptive beamformer algorithm;
receiving an output estimation from a non-linear spatial filter that is based on the input signals, wherein the non-linear spatial filter uses the input signals to compute a probability of a signal direction for each of the input signals, and wherein the non-linear spatial filter computes the output estimation using output from the time invariant beamformer and the probability computed;
computing parameters of the adaptive beamformer algorithm using the output estimation from the non-linear spatial filter and an output signal from the adaptive beamformer, wherein the output signal is used to compute weights for each of the plurality of microphones; and
processing the input signals into the output signal using the parameters of the adaptive beamformer algorithm.
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Abstract
Described is a audio signal processing technology in which an adaptive beamformer processes input signals from microphones based on an estimate received from a pre-filter. The adaptive beamformer may compute its parameters (e.g., weights) for each frame based on the estimate, via a magnitude-domain objective function or log-magnitude-domain objective function. The pre-filter may include a time invariant beamformer and/or a non-linear spatial filter, and/or may include a spectral filter. The computed parameters may be adjusted based on a constraint, which may be selectively applied only at desired times.
32 Citations
20 Claims
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1. In a computing environment, a method comprising:
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receiving input signals from a plurality of microphones at an adaptive beamformer and a time invariant beamformer, the adaptive beamformer including an adaptive beamformer algorithm; receiving an output estimation from a non-linear spatial filter that is based on the input signals, wherein the non-linear spatial filter uses the input signals to compute a probability of a signal direction for each of the input signals, and wherein the non-linear spatial filter computes the output estimation using output from the time invariant beamformer and the probability computed; computing parameters of the adaptive beamformer algorithm using the output estimation from the non-linear spatial filter and an output signal from the adaptive beamformer, wherein the output signal is used to compute weights for each of the plurality of microphones; and processing the input signals into the output signal using the parameters of the adaptive beamformer algorithm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. In a computing environment, a system comprising:
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at least one processor; a memory communicatively coupled to the at least one processor; an output estimation mechanism implemented on the at least one processor and configured to receive input signals from a plurality of microphones and configured to generate an output estimation including magnitude information, wherein the input signals are used to compute a probability of a signal direction for each of the input signals, and wherein the output estimation mechanism generates the output estimation using output from a time invariant beamformer and the probability computed, wherein the time invariant beamformer generates the output using the input signals; and an adaptive beamformer having an adaptive beamformer algorithm, the adaptive beamformer configured to receive the output estimation and the input signals, the adaptive beamformer algorithm configured to combine the input signals using weights dependent on the output estimation to generate an output signal, wherein the weights are computed for each of the plurality of microphones using the output estimation, and wherein the output signal is based on the weights computed and the input signals. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. One or more tangible computer-readable storage devices having computer-executable instructions stored thereon, which in response to execution by a computer, cause the computer to perform steps comprising:
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receiving input signals from a plurality of microphones at a time invariant beamformer, a non-linear spatial filter, and an adaptive beamformer; using the input signals to compute a probability of a signal direction for each of the input signals at the non-linear spatial filter; receiving an output from the time invariant beamformer at the non-linear spatial filter; using the output from the time invariant beamformer and the probability of the signal direction for each of the input signals to compute an output estimation at the non-linear spatial filter; receiving the output estimation from the non-linear spatial filter at the adaptive beamformer; using the output estimation and a combined signal from the adaptive beamformer to compute weights for each of the plurality of microphones; and outputting the combined signal from the adaptive beamformer that is based on the weights for each of the plurality of microphones and the input signals. - View Dependent Claims (18, 19, 20)
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Specification