公开(公告)号：EP3125429A1

公开(公告)日：2017-02-01

申请号：EP15178698.5

申请日：2015-07-28

申请人： Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. ,  Friedrich-Alexander-Universität Erlangen-Nürnberg

发明人： Valero, Maria Luis ,  Habets, Emanuel ,  Mabande, Edwin ,  Lombard, Anthony ,  Mahne, Dirk ,  Birzer, Bernhard

IPC分类号： H03H21/00

CPC分类号： H03H21/0027 ,  H03H2021/0058

摘要： Partitioned block frequency domain adaptive filter device comprising:
a frequency domain adaptive filter configured for filtering a frequency domain representation of a time domain input signal depending on a set of filter coefficients consisting of a plurality of blocks of filter coefficients in order to produce a filtered signal;
a plurality of parallel arranged filter update blocks, each of the filter update blocks being configured for updating one of the blocks of filter coefficients based on an update signal gathered by a circular correlation of a block of the frequency domain representation signal and a frequency domain control signal comprising a representation of the filtered signal;
wherein each of the filter update blocks comprises an adaptation module configured for executing an adaptation sequence comprising the steps of
calculating an approximation of a constrained gradient update for the filter coefficients of the respective block of filter coefficients by applying an approximated constraining matrix having a lesser complexity than a constraining matrix to an unconstrained gradient update for the filter coefficients of the respective block of filter coefficients, wherein the unconstrained gradient update is derived from the update signal, and
calculating a cumulative error introduced on the unconstrained gradient update by applying the approximated constraining matrix to the unconstrained gradient update;
wherein each of the filter update blocks comprises a correction module configured for executing a correction sequence comprising the steps of
calculating a corrected constrained gradient update for the filter coefficients of the respective block of filter coefficients by applying the frequency domain constraining matrix to a sum of the approximation of the constrained gradient update and the cumulative error.

摘要翻译： 分区块频域自适应滤波器装置，包括：频域自适应滤波器，被配置为根据由多个滤波器系数块组成的滤波器系数的集合来滤波时域输入信号的频域表示，以产生滤波信号 ; 多个并行布置的滤波器更新块，每个滤波器更新块被配置用于基于通过频域表示信号的块的循环相关收集的更新信号和频域控制来更新滤波器系数块中的一个 信号，包括滤波信号的表示; 其中每个滤波器更新块包括被配置为执行自适应序列的自适应模块，该适配序列包括以下步骤：通过应用具有较小复杂度的近似约束矩阵来计算滤波器系数的相应块的滤波器系数的约束梯度更新的近似 而不是约束矩阵，以用于滤波器系数的各个滤波器系数的滤波器系数的非约束梯度更新，其中从更新信号导出非约束梯度更新，并且通过应用近似约束矩阵来计算在非约束梯度更新上引入的累积误差 到无约束的梯度更新; 其中每个滤波器更新块包括被配置为执行校正序列的校正模块，该校正序列包括以下步骤：通过将频域约束矩阵应用于滤波器系数的和来计算滤波器系数的各个滤波器系数的滤波器系数的校正约束梯度更新 约束梯度更新的近似和累积误差。

公开(公告)号：EP3826011A1

公开(公告)日：2021-05-26

申请号：EP21152041.6

申请日：2015-07-21

申请人： FRAUNHOFER-GESELLSCHAFT zur Förderung der angewandten Forschung e.V.

发明人： Schubert, Benjamin ,  Jander, Manuel ,  Lombard, Anthony ,  Dietz, Martin ,  Multrus, Markus

IPC分类号： G10L25/03 ,  G10L25/21 ,  G10L19/012 ,  G10L21/0216

摘要： A method for estimating noise in an audio signal includes determining an energy value for the audio signal, converting the energy value into the log2-domain, and estimating a noise level for the audio signal based on the converted energy value directly in the log2-domain. The energy value is converted into the log2-domain as follows: E n_log = ⌊ log 2 1 + E n_lin ⋅ 2 N ⌋ 2 N
└ x ┘
floor (x), indicating the largest integer less than or equal to x,
E n_log
energy value of band n in the log2-domain,
E n_lin
energy value of band n in the linear domain,
N
quantization resolution.
Determining the energy value includes obtaining a power spectrum of the audio signal by a combination of several transformations covering different parts of the spectrum.