Device and method for processing a real subband signal for reducing aliasing effects

A method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• weighting, by a weighter, the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating, by a correction term determiner, a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining, by a combiner, the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating an unweighted correction term in dependence on the other subband signal, and weighting the unweighted correction term by a difference of the weighting factor for the subband signal and the weighting factor for the other subband signal, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

An analysis filter bank comprising:

• a generator for generating a plurality of subband signals from a discrete-time signal;
• and
• a device for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the device comprising:
• a weighter for weighting the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• a correction term determiner for calculating a correction term, the correction term determiner being implemented to calculate the correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• a combiner for combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner is implemented to calculate an unweighted correction term in dependence on the other subband signal, and to weight the unweighted correction term by a difference of the weighting factor for the subband signal and the weighting factor for the other subband signal
• for each subband signal to achieve processed subband signals,
• wherein at least one of the generator, the device for processing, the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A synthesis filter bank comprising:

• for every subband signal of a plurality of subband signals having been generated by an analysis filter bank, a device for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the device comprising:
• a weighter for weighting the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• a correction term determiner for calculating a correction term, the correction term determiner being implemented to calculate the correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• a combiner for combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner is implemented to calculate an unweighted correction term in dependence on the other subband signal, and to weight the unweighted correction term by a difference of the weighting factor for the subband signal and the weighting factor for the other subband signal
• to achieve processed subband signals;
• and
• a plurality of synthesis filters for filtering the processed subband signals to achieve synthesis-filtered subband signals;
• and
• a summer for summing the filtered subband signals to achieve a discrete-time signal,
• wherein at least one of the device for processing, the weighter, the correction term determiner, the combiner, the plurality of synthesis filters or the summer comprises a hardware implementation.

A method for filtering a discrete-time signal, comprising:

• generating, by a generator, a plurality of subband signals from the discrete-time signal;
• and
• for every subband signal, processing, by a device for processing, the subband signal by a method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the method comprising:
• weighting, by a weighter, the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating, by a correction term determiner, a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining, by a combiner, the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating an unweighted correction term in dependence on the other subband signal, and weighting the unweighted correction term by a difference of the weighting factor for the subband signal and the weighting factor for the other subband signal,
• to achieve processed subband signals,
• wherein at least one of the generator, the device for processing, the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A method for synthesizing a signal, comprising:

• for every subband signal of a plurality of subband signals having been generated by an analysis filter bank, processing, by a device for processing, the subband signal by a method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the method comprising:
• weighting, by a weighter, the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating, by a correction term determiner, a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining, by a combiner, the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating an unweighted correction term in dependence on the other subband signal, and weighting the unweighted correction term by a difference of the weighting factor for the subband signal and the weighting factor for the other subband signal;
• and
• synthesis-filtering, by a plurality of synthesis filters, the processed subband signals to achieve synthesis-filtered subband signals;
• and
• summing, by a summer, the filtered subband signals to achieve a synthesized signal,
• wherein at least one of the device for processing, the weighter, the correction term determiner, the combiner, the plurality of synthesis filters or the summer comprises a hardware implementation.

A non-transitory storage medium having stored thereon a computer program comprising a program code for performing the method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the method comprising:

• weighting the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating an unweighted correction term in dependence on the other subband signal, and weighting the unweighted correction term by a difference of the weighting factor for the subband signal and the weighting factor for the other subband signal,
• when the computer program runs on a computer.

A device for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• a weighter for weighting the subband signal of the plurality of real subband signals by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• a correction term determiner for calculating a correction term, the correction term determiner being implemented to calculate the correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• a combiner for combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner is implemented to calculate the correction term as a linear combination of the subband signal filtered by a first filter and the other subband signal filtered by another filter, the filters being low-pass filters or high-pass filters comprising a filter length between 1 and 20, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A device for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• a weighter for weighting the subband signal of the plurality of real subband signals by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• a correction term determiner for calculating a correction term, the correction term determiner being implemented to calculate the correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• a combiner for combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner is implemented to calculate the correction term according to the following equation:
• KT=pkLk(z)+qkUk(z),
• pk equaling a difference between the weighting factor ck−1 for a neighboring subband signal xk−1 and the weighting factor ck of the subband signal xk, qk being a difference between another neighboring subband signal xk+1 and the weighting factor ck of the subband signal Xk, Lk being an unweighted correction term of the one neighboring subband signal xk−1, and Uk being an unweighted correction term caused by another neighboring subband signal xk+1, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A device for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• a weighter for weighting the subband signal of the plurality of real subband signals by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• a correction term determiner for calculating a correction term, the correction term determiner being implemented to calculate the correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• a combiner for combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner comprises filters comprising a filter length which is smaller than a filter length of a subband filter to generate the subband signal or the other subband signal, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• weighting, by a weighter, the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating, by a correction term determiner, a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining, by a combiner, the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating the correction term as a linear combination of the subband signal filtered by a first filter and the other subband signal filtered by another filter, the filters being low-pass filters or high-pass filters comprising a filter length between 1 and 20, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• weighting, by a weighter, the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating, by a correction term determiner, a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining, by a combiner, the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating the correction term according to the following equation:
• KT=pkLk(z)+qkUk(z),
• pk equaling a difference between the weighting factor ck−1 for a neighboring subband signal xk−1 and the weighting factor ck of the subband signal xk, qk being a difference between another neighboring subband signal xk+1 and the weighting factor ck of the subband signal xk, Lk being an unweighted correction term of the one neighboring subband signal xk−1, and Uk being an unweighted correction term caused by another neighboring subband signal xk+1, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, comprising:

• weighting, by a weighter, the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating, by a correction term determiner, a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining, by a combiner, the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner comprises filters comprising a filter length which is smaller than a filter length of a subband filter to generate the subband signal or the other subband signal, and
• wherein at least one of the weighter, the correction term determiner, and the combiner comprises a hardware implementation.

A non-transitory storage medium having stored thereon a computer program comprising a program code for performing the method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the method comprising:

• weighting the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating the correction term as a linear combination of the subband signal filtered by a first filter and the other subband signal filtered by another filter, the filters being low-pass filters or high-pass filters comprising a filter length between 1 and 20,
• when the computer program runs on a computer.

A non-transitory storage medium having stored thereon a computer program comprising a program code for performing the method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the method comprising:

• weighting the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the calculating the correction term comprises calculating the correction term according to the following equation:
• KT=pkLk(z)+qkUk(z),
• pk equaling a difference between the weighting factor ck−1 for a neighboring subband signal xk−1 and the weighting factor ck of the subband signal xk, qk being a difference between another neighboring subband signal xk+1 and the weighting factor ck of the subband signal xk, Lk being an unweighted correction term of the one neighboring subband signal xk−1, and Uk being an unweighted correction term caused by another neighboring subband signal xk+1, and
• when the computer program runs on a computer.

A non-transitory storage medium having stored thereon a computer program comprising a program code for performing the method for processing a real subband signal of a plurality of real subband signals which are a representation of a real discrete-time signal generated by an analysis filter bank, the method comprising:

• weighting the subband signal by a weighting factor determined for the subband signal to achieve a weighted subband signal;
• calculating a correction term using at least one other subband signal and using another weighting factor provided for the other subband signal, the other weighting factor differing from the weighting factor;
• and
• combining the weighted subband signal and the correction term to achieve a corrected subband signal,
• wherein the correction term determiner comprises filters comprising a filter length which is smaller than a filter length of a subband filter to generate the subband signal or the other subband signal, and
• when the computer program runs on a computer.