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68 条记录 (耗时 0.028 秒)

    Low delay modulated filter bank
    5.
    发明授权
    Low delay modulated filter bank 有权

    公开(公告)号：US09318118B2

    公开(公告)日：2016-04-19

    申请号：US14807554

    申请日：2015-07-23

    申请人： Dolby International AB

    发明人： Per Ekstrand

    IPC分类号： G10L21/00 ,  G06F17/10 ,  H03H17/02

    CPC分类号： H04R3/04 ,  G06F17/10 ,  G06F17/11 ,  G10L19/008 ,  G10L19/0204 ,  G10L19/0208 ,  G10L19/26 ,  G10L19/265 ,  G10L21/00 ,  H03H17/0201 ,  H03H17/0248 ,  H03H17/0266 ,  H03H17/0275 ,  H03H17/0294 ,  H03H2017/0297 ,  H04S7/307

    摘要： The document relates to modulated sub-sampled digital filter banks, as well as to methods and systems for the design of such filter banks. In particular, the present document proposes a method and apparatus for the improvement of low delay modulated digital filter banks. The method employs modulation of an asymmetric low-pass prototype filter and a new method for optimizing the coefficients of this filter. Further, a specific design for a 64 channel filter bank using a prototype filter length of 640 coefficients and a system delay of 319 samples is given. The method substantially reduces artifacts due to aliasing emerging from independent modifications of subband signals, for example when using a filter bank as a spectral equalizer. The method is preferably implemented in software, running on a standard PC or a digital signal processor (DSP), but can also be hardcoded on a custom chip. The method offers improvements for various types of digital equalizers, adaptive filters, multiband companders and spectral envelope adjusting filter banks used in high frequency reconstruction (HFR) or parametric stereo systems.

    Filter system capable of automatically adjusting bandwidth and method of automatically adjusting bandwidth of a filter
    6.
    发明授权
    Filter system capable of automatically adjusting bandwidth and method of automatically adjusting bandwidth of a filter 有权
    能够自动调节带宽的滤波器系统和自动调节滤波器带宽的方法

    公开(公告)号：US08476968B2

    公开(公告)日：2013-07-02

    申请号：US13366382

    申请日：2012-02-06

    申请人： Ping-Hung Kao

    发明人： Ping-Hung Kao

    IPC分类号： H03B1/00

    CPC分类号： H03H17/0294 ,  H03H2017/0297 ,  H03H2210/015

    摘要： A filter system capable of automatically adjusting bandwidth includes a filter and an adaptive unit. The filter is used for filtering a digital signal to generate an output signal to an application unit. The adaptive unit is used for generating an adjustment signal to the filter according to the digital signal and the output signal. The filter dynamically adjusts bandwidth of the filter according to the adjustment signal.

    摘要翻译： 能够自动调整带宽的滤波器系统包括滤波器和自适应单元。 滤波器用于对数字信号进行滤波以产生到应用单元的输出信号。 自适应单元用于根据数字信号和输出信号向滤波器生成调整信号。 滤波器根据调整信号动态调整滤波器的带宽。

    Adaptive FIR filter and method
    7.
    发明申请
    Adaptive FIR filter and method 有权
    自适应FIR滤波器和方法

    公开(公告)号：US20050094723A1

    公开(公告)日：2005-05-05

    申请号：US10954137

    申请日：2004-09-28

    申请人： Hiroshi Takatori

    发明人： Hiroshi Takatori

    IPC分类号： G06F20060101 ,  H03K5/159

    CPC分类号： H03H17/0607 ,  H03H17/0227 ,  H03H17/06 ,  H03H21/0012 ,  H03H21/0067 ,  H03H2017/0297 ,  H03H2218/025 ,  H04L25/03057 ,  H04L25/03885 ,  H04L25/4921

    摘要： Finite impulse response filters are commonly used in high speed data communications electronics for reducing error rates in multilevel symbol encoding schemes. Schemes such as pulse amplitude modulation and quadrature amplitude modulation may have higher error rates for symbols with low signal to noise ratios. By selectively updating the tap coefficients of the filter based on the symbols received, a more robust, accurate filter can be built.

    摘要翻译： 有限脉冲响应滤波器通常用于高速数据通信电子设备中，用于降低多电平符号编码方案中的误码率。 诸如脉冲幅度调制和正交幅度调制的方案对于具有低信噪比的符号可能具有较高的误码率。 通过基于所接收的符号选择性地更新滤波器的抽头系数，可以构建更鲁棒，精确的滤波器。

    Adaptive removal of resonance-induced noise
    8.
    发明授权
    Adaptive removal of resonance-induced noise 有权
    自适应去除谐振引起的噪声

    公开(公告)号：US06611602B1

    公开(公告)日：2003-08-26

    申请号：US09324998

    申请日：1999-06-02

    申请人： Stanley A. White ,  Jeffrey P. Woodard ,  Michael Alan Soderstrand ,  Karl Einar Nelson ,  Phong Vu Nguyen Dao

    发明人： Stanley A. White ,  Jeffrey P. Woodard ,  Michael Alan Soderstrand ,  Karl Einar Nelson ,  Phong Vu Nguyen Dao

    IPC分类号： H03G500

    CPC分类号： H03H17/0294 ,  H03H17/025 ,  H03H17/0288 ,  H03H17/04 ,  H03H2017/0297

    摘要： Noise is removed from the digitized output of a sensor, subject to undesired resonance, even when the resonant frequency is unknown or drifts, with sufficiently low phase delay for the sensor to be used in closed-loop control. A very narrow notch filter which removes the resonance-induced noise is recursive (IIR) and therefore has a low phase delay. However, the apparatus which determines the center frequency of the notch filter is non-recursive, and therefore stable. It includes a tunable FIR filter which tracks the same resonance that we wish the IIR filter to remove. Tuning the FIR filter to minimize the output of the FIR filter therefore tunes the notch frequency to align with the resonant frequency. The tuning parameter which adaptively produces this result is suitably scaled and biased, and is applied to the IIR filter.

    摘要翻译： 即使谐振频率未知或漂移，即使传感器用于闭环控制的相位延迟足够低，噪声也会从传感器的数字化输出中消失。 去除谐振感应噪声的非常窄的陷波滤波器是递归的（IIR），因此具有低相位延迟。 然而，确定陷波滤波器的中心频率的装置是非递归的，因此是稳定的。 它包括一个可调FIR滤波器，跟踪我们希望IIR滤波器去除的相同谐振。 调谐FIR滤波器以最小化FIR滤波器的输出，因此调谐陷波频率与谐振频率对齐。 自适应地产生该结果的调谐参数被适当地缩放和偏置，并且被应用于IIR滤波器。

    Symmetrical filtering apparatus and method therefor
    9.
    发明授权
    Symmetrical filtering apparatus and method therefor 失效
    对称过滤装置及其方法

    公开(公告)号：US5737254A

    公开(公告)日：1998-04-07

    申请号：US549503

    申请日：1995-10-27

    申请人： John E. Lane ,  Dan Hoory ,  Eduardo F. Martinez

    发明人： John E. Lane ,  Dan Hoory ,  Eduardo F. Martinez

    IPC分类号： H03H17/02 ,  H03H17/04 ,  G06F17/10

    CPC分类号： H03H17/04 ,  H03H17/0294 ,  H03H2017/0297

    摘要： A data processing system (10) implements a symmetrical filtering function about the unity gain line using a single filter (33). The data processing system (10) includes a bus (12), an I/O port (12), memory (16), and a processor (18). The I/O port (12) receives filter control parameters (20) and receives and transmits digitized data. The processor receives the filter control parameters (20) and calculates filter coefficients (44, 48, 52). The processor (18) implements the single stage filter (33) based upon the filter coefficients (44, 48, 52) to filter the digitized input data (22) and produce filtered digitized data (24). The single stage filter (33) may include a band pass, high pass, or low pass function. The single stage filtering function (33) produces a filtering function that is symmetrical about the unity gain line. Variable Q operation of the data processing system (10) allows Q of the filtering function to vary with boost/cut level (34). A method (150), a graphic equalizer (200), and digital telephone (250) also incorporate the symmetrical filtering function.

    摘要翻译： 数据处理系统（10）使用单个滤波器（33）实现关于单位增益线的对称滤波功能。 数据处理系统（10）包括总线（12），I / O端口（12），存储器（16）和处理器（18）。 I / O端口（12）接收滤波器控制参数（20）并接收并发送数字化数据。 处理器接收滤波器控制参数（20）并计算滤波器系数（44,48,52）。 处理器（18）基于滤波器系数（44,48,52）来实现单级滤波器（33），以对数字化的输入数据（22）进行滤波并产生滤波的数字化数据（24）。 单级滤波器（33）可以包括带通，高通或低通功能。 单级滤波功能（33）产生关于单位增益线对称的滤波函数。 数据处理系统（10）的可变Q操作允许滤波功能的Q随着升压/切断电平而变化（34）。 方法（150），图形均衡器（200）和数字电话（250）还包括对称滤波功能。