公开(公告)号：US06647365B1

公开(公告)日：2003-11-11

申请号：US09586068

申请日：2000-06-02

Applicant: Christof Faller

Inventor： Christof Faller

IPC: G10L1900

CPC classification number: G10L25/78 ,  G10L19/0204 ,  G10L21/0216

Abstract: Noise-like signal components are detected within arbitrary regions of the time-frequency plane. Various transforms are applied to G time domain samples with different spectral/temporal resolutions. The flatness of the time domain samples and the frequency samples for each transform are compared. If the computed flatness measures are about the same, the samples are assumed to be noisy. Noise-like signal components can be detected using a general filterbank within a limited time interval and frequency range by decomposing the signal into N subbands. To each group of G subband samples in time {tk}, a linear orthogonal transform is applied to obtain the frequency domain samples {fi}. The flatness of the time domain samples is compared to the flatness of the frequency domain samples {fi}. A filterbank with uniform frequency-tiling can be used to detect noise-like signal components. To detect noise with a bandwidth of a given noise detection partition, two linear transforms are applied to the coefficients within the partition. A linear orthogonal synthesis transform is applied over frequency and a linear orthogonal analysis transform is applied over time in a noise detection partition to yield coefficients with maximum time and frequency resolution {tk} and {fi}, respectively. The flatness of the time domain samples {tk} and the frequency domain samples {fi} are compared to decide whether the frequency noise detection partition is noise-like. Noise with a non-flat spectrum can be detected by preprocessing the signal according to its inverse spectral envelope before detecting noise-like signal components with a non-flat spectral/temporal envelope.

Abstract translation: 在时频平面的任意区域内检测出噪声状的信号分量。 将各种变换应用于具有不同光谱/时间分辨率的G时域样本。 比较时域样本的平坦度和每个变换的频率样本。 如果计算出的平坦度度量大致相同，则假设样本是嘈杂的。 通过将信号分解为N个子带，可以在有限的时间间隔和频率范围内使用通用滤波器组来检测噪声状信号分量。 在时间{tk}的每组G个子带样本中，应用线性正交变换来获得频域样本{fi}。 将时域样本的平坦度与频域样本{fi}的平坦度进行比较。 可以使用具有均匀频率平铺的滤波器组来检测类似噪声的信号分量。 为了利用给定噪声检测分区的带宽来检测噪声，将两个线性变换应用于分区内的系数。 在频率上进行线性正交合成变换，并且在噪声检测分区中随时间施加线性正交分析变换，以分别产生具有最大时间和频率分辨率{tk}和{fi}的系数。 比较时域样本{tk}和频域样本{fi}的平坦度，以确定频率噪声检测分区是否类噪声。 通过在检测具有非平坦频谱/时间包络的类似噪声的信号分量之前，根据其反频谱包络对信号进行预处理，可以检测具有非平坦频谱的噪声。