Low-Complexity Spectral Analysis/Synthesis Using Selectable Time Resolution
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorAnisse Taleb
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Abstract
The signal processing is based on the concept of using a time-domain aliased (12, TDA) frame as a basis for time segmentation (14) and spectral analysis (16), performing segmentation in time based on the time-domain aliased frame and performing spectral analysis based on the resulting time segments. The time resolution of the overall ?segmented? time-to-frequency transform can thus be changed by simply adapting the time segmentation to obtain a suitable number of time segments based on which spectral analysis is applied. The overall set of spectral coefficients, obtained for all the segments, provides a selectable time-frequency tiling of the original signal frame.
Claims44
A method for signal processing operating on overlapped frames of a time-domain input signal, said method comprising the steps of:
- performing time-domain aliasing (TDA) based on an overlapped frame to generate a corresponding time-domain aliased frame;
- performing segmentation in time based on the time-domain aliased frame to generate at least two segments;
- and
- performing spectral analysis based on said at least two segments to obtain, for each segment, coefficients representative of the frequency content of the segment.
A device for signal processing operating on overlapped frames of an input signal, said device comprising:
- means for performing time-domain aliasing (TDA) based on an overlapped frame to generate a time-domain aliased frame;
- means for performing segmentation in time based on the time-domain aliased frame to generate at least two segments;
- and
- a spectral analyzer configured for performing segmented spectral analysis based on said at least two segments to obtain, for each segment, coefficients representative of the frequency content of the segment.
An audio encoder operating on overlapped frames of an audio signal, said audio encoder comprising:
- a time-domain aliasing (TDA) unit configured to generate a time-domain aliased frame based on an overlapped frame;
- a time-segmentation unit configured to generate a selectable number N of segments based on the time-domain aliased frame, where N is equal to or greater than 2;
- and
- a transform coder configured to perform segmented spectral analysis based on said N segments to obtain, for each segment, spectral coefficients representative of the frequency content of the segment.
A method for signal processing operating based on spectral coefficients representative of a time-domain signal, said method comprising the steps of:
- performing inverse spectral analysis based on different sub-sets of said spectral coefficients to generate, for each sub-set of spectral coefficients, an inverse-transformed sub-frame;
- performing inverse time-segmentation based on overlapped inverse-transformed sub-frames to combine said inverse-transformed sub-frames into a time-domain aliased frame;
- and
- performing inverse time-domain aliasing based on said time-domain aliased frame to enable reconstruction of said time-domain signal.
An audio decoder operating based on spectral coefficients representative of a time-domain signal, said audio decoder comprising:
- an inverse transformer operating based on different sub-sets of said spectral coefficients to generate, for each sub-set of spectral coefficients, an inverse-transformed sub-frame;
- means for performing inverse time-segmentation based on overlapped inverse-transformed sub-frames and combining said inverse-transformed sub-frames to generate a time-domain aliased frame;
- and
- means for performing inverse time-domain aliasing based on said time-domain aliased frame to enable reconstruction of said time-domain signal.
Dependencies are inferred from the claim text.