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US 10,834,505 B2Granted
Apparatus and a method for unwrapping phase differences
AssigneeHuawei Technologies Duesseldorf GmbH
InventorsJürgen Geiger, Kainan Chen, Peter Grosche
Life of this patent
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Abstract
An apparatus configured to obtain a plurality of phase differences is provided. Each phase difference represents a difference in phase between a spectral component in a first sound signal and a corresponding spectral component in a second sound signal, to estimate an aliasing frequency. Phase differences in frequency bands above the aliasing frequency are expected to be wrapped, and to unwrap the plurality of phase differences in dependence on the estimated aliasing frequency. A phase difference obtained from spectral components that are comprised in one frequency band is unwrapped independently of any phase difference obtained from spectral components that are comprised in another frequency band.
Claims20
An apparatus comprising a processor that is configured to:
- obtain a plurality of phase differences, wherein each phase difference represents a difference in phase between (i) a spectral component in a first sound signal captured by a first microphone, and (ii) a spectral component in a second sound signal captured by a second microphone,
- wherein each spectral component is part of a signal spectrum for its respective sound signal,
- wherein each signal spectrum represents its respective sound signal as a plurality of spectral components, and
- wherein each spectral component is comprised in a respective frequency band of a plurality of frequency bands representing the respective sound signal;
- estimate an aliasing frequency;
- and
- unwrap the plurality of phase differences in dependence on the estimated aliasing frequency, including determining a wrapping direction for unwrapping each phase difference by assigning each phase difference to one of one or more sets, wherein:
- (a) each set comprises phase differences obtained from spectral components that are comprised in a particular segment of the plurality of frequency bands of the first and second sound signals;
- and
- (b) each phase difference is assigned to one of the sets in dependence on the estimated aliasing frequency, such that none of the phase differences assigned to a particular set is wrapped relative to the other phase differences assigned to the same set;
- fit a line to each set of phase differences;
- and
- estimate the wrapping direction in dependence on slopes of the lines fitted to the sets of phase differences,
- wherein each phase difference obtained from spectral components that are comprised in one frequency band is unwrapped independently of any phase difference obtained from spectral components that are comprised in another frequency band.
11 more elements
A method implemented by a processor of an apparatus, the method comprising:
- obtaining a plurality of phase differences, wherein each phase difference represents a difference in phase between (i) a spectral component in a first sound signal captured by a first microphone, and (ii) a spectral component in a second sound signal captured by a second microphone,
- wherein each spectral component is part of a signal spectrum for its respective sound signal,
- wherein each signal spectrum represents its respective sound signal as a plurality of spectral components, and
- wherein each spectral component is comprised in a respective frequency band of a plurality of frequency bands representing the respective sound signal;
- estimating an aliasing frequency;
- unwrapping the plurality of phase differences in dependence on the estimated aliasing frequency, including determining a wrapping direction for unwrapping each phase difference by assigning each phase difference to one of one or more sets, wherein:
- (a) each set comprises phase differences obtained from spectral components that are comprised in a particular segment of the plurality of frequency bands of the first and second sound signals;
- and
- (b) each phase difference is assigned to one of the sets in dependence on the estimated aliasing frequency, such that none of the phase differences assigned to a particular set is wrapped relative to the other phase differences assigned to the same set;
- fitting a line to each set of phase differences;
- and
- estimating the wrapping direction in dependence on slopes of the lines fitted to the sets of phase differences,
- wherein each phase difference obtained from spectral components that are comprised in one frequency band is unwrapped independently of any phase difference obtained from spectral components that are comprised in another frequency band.
10 more elements
A non-transitory machine-readable storage medium having stored thereon processor-executable instructions, which when executed by a processor of the apparatus, cause the apparatus to implement a method comprising:
- obtaining a plurality of phase differences, wherein each phase difference represents a difference in phase between (i) a spectral component in a sound signal captured by a first microphone, and (ii) a spectral component in a second sound signal captured by a second microphone,
- wherein each spectral component is part of a signal spectrum for its respective sound signal,
- wherein each signal spectrum representing its respective sound signal as a plurality of spectral components, and
- wherein each spectral component is comprised in a respective frequency band of a plurality of frequency bands representing the respective sound signal;
- estimating an aliasing frequency;
- and
- unwrapping the plurality of phase differences in dependence on the estimated aliasing frequency, including determining a wrapping direction for unwrapping each phase difference by assigning each phase difference to one of one or more sets, wherein:
- (a) each set comprises phase differences obtained from spectral components that are comprised in a particular segment of the plurality of frequency bands of the first and second sound signals;
- and
- (b) each phase difference is assigned to one of the sets in dependence on the estimated aliasing frequency, such that none of the phase differences assigned to a particular set is wrapped relative to the other phase differences assigned to the same set;
- fitting a line to each set of phase differences;
- and
- estimating the wrapping direction in dependence on slopes of the lines fitted to the sets of phase differences,
- wherein each phase difference obtained from spectral components that are comprised in one frequency band is unwrapped independently of any phase difference obtained from spectral components that are comprised in another frequency band.
11 more elements
Dependencies are inferred from the claim text.