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IIR Halfband Interpolator

使用多相IIR半带滤波器插值信号

Library

过滤/过滤器设计

dspfdesign

  • IIR Halfband Interpolator block

Description

这IIR Halfband Interpolator块对输入信号进行有效的多相插值，占两个因子。要设计半带滤波器，您可以指定块以使用椭圆设计或准线性相设计。该块使用这些设计方法来计算滤波器系数。为了过滤输入，该块使用多相结构。多相结构中的AllPass过滤器的最小乘数形式。

Elliptic design introduces nonlinear phase and creates the filter using fewer coefficients than quasi linear design. Quasi-linear phase design overcomes phase nonlinearity at the cost of additional coefficients.

Alternatively, instead of designing the halfband filter using a design method, you can specify the filter coefficients directly. When you choose this option, the allpass filters in the two branches of the polyphase implementation can be in a minimum multiplier form or in a wave digital form.

You can also use the block to implement the synthesis portion of a two-band filter bank to synthesize a signal from lowpass and highpass subbands.

输入信号可以是实现或复杂值的列矢量或矩阵。如果输入信号是矩阵，则矩阵的每一列被视为独立通道。

参数

Filter specification

参数used to design the IIR halfband filter. Because the filter design has only two degrees of freedom, you can specify only two of the three parameters:

  • 过渡宽度和停止带衰减（默认） - 使用Transition width (Hz)andStopband attenuation (dB)。该设计是最低订单设计。

  • Filter order and transition width- 使用Filter orderandTransition width (Hz)。

  • 过滤器秩序和阻带attenuation- 使用Filter orderandStopband attenuation (dB)。

  • 系数- 使用启用参数直接指定过滤器系数。

Transition width (Hz)

IIR半带滤波器的过渡宽度，指定为Hz中的真实正标量。过渡宽度必须小于输入样本率的一半。此参数适用Filter specificationis set toFilter order and transition widthor过渡宽度和停止带衰减。默认值为4.1e3。

Filter order

Filter order, specified as a finite positive integer. If you set设计方法至Elliptic， 然后Filter ordermust be an odd integer greater than one. If you set设计方法至Quasi-linear phase， 然后Filter ordermust be a multiple of four. This parameter applies whenFilter specificationis set toFilter order and transition widthor过滤器秩序和阻带attenuation。默认值为9。

Stopband attenuation (dB)

Minimum attenuation needed in the stopband of the IIR halfband filter, specified as a real positive scalar in dB. This parameter applies whenFilter specificationis set to过滤器秩序和阻带attenuationor过渡宽度和停止带衰减。默认值为80。

设计方法

设计方法for the IIR halfband filter.

  • Elliptic(default) — The filter has nonlinear phase and uses few coefficients.

  • Quasi-linear phase- 多相滤波器结构的第一个分支是纯延迟，这会导致大约线性相响应。

设置时适用此参数Filter specification任何选项除外系数。

Internal allpass structure

内部Allpass过滤器实现结构，指定为最小乘数orWave Digital Filter。设置时适用此参数Filter specification至系数。每个结构都使用设置的不同系数，独立存储在相应的系数属性中。默认值为最小乘数。

Make the first branch a pure delay

When you select this check box, the first branch of the polyphase filter structure becomes a pure delay, and the分支1 Allpass多项式系数and分支1波数字系数parameters do not apply. This parameter applies when you setFilter specification至系数。

By default, this check box is selected.

Delay length in samples for branch 1

Length of the first branch delay, specified as a finite positive scalar. This parameter applies when you setFilter specification至系数并选择Make the first branch a pure delay。默认值为1。

从输入端口指定系数

When you select this check box, the branch 1 allpass polynomial coefficients and branch 2 allpass polynomial coefficients are input through the input portscoeffs1andcoeffs2。当您清除此复选框时，系数将在“块”对话框中指定分支1 Allpass多项式系数and分支2 Allpass多项式系数参数。

设置时适用此参数Filter specification至系数andInternal allpass structure至最小乘数。

分支1 Allpass多项式系数

Allpass polynomial filter coefficients of the first branch, specified as ann-by-1orn-by-2矩阵nfirst-order or second-order allpass sections. This parameter applies only when you setFilter specification至系数andInternal allpass structure至最小乘数。默认值为[0.1284563; 0.7906755].

设置时适用此参数Filter specification至系数， 放Internal allpass structure至最小乘数，清除从输入端口指定系数范围。

此参数可调节。也就是说，您可以在模拟过程中更改其价值。

分支2 Allpass多项式系数

Allpass polynomial filter coefficients of the second branch, specified as ann-by-1orn-by-2矩阵nfirst-order or second-order allpass sections. This parameter applies only when you setFilter specification至系数andInternal allpass structure至最小乘数。默认值为0.4295667。

设置时适用此参数Filter specification至系数， 放Internal allpass structure至最小乘数，清除从输入端口指定系数范围。

此参数可调节。也就是说，您可以在模拟过程中更改其价值。

分支1波数字系数

Allpass filter coefficients of the first branch in Wave Digital Filter form, specified as ann-by-1orn-by-2矩阵nfirst-order or second-order allpass sections. This parameter applies only when you setFilter specification至系数andInternal allpass structure至Wave Digital Filter。默认值为[0.1284563; 0.7906755].

设置时适用此参数Filter specification至系数andInternal allpass structure至Wave Digital Filter。

分支2波数字系数

Allpass filter coefficients of the second branch in Wave Digital Filter form, specified as ann-by-1orn-by-2矩阵nfirst-order or second-order allpass sections. This parameter applies only when you setFilter specification至系数andInternal allpass structure至Wave Digital Filter。默认值为0.4295667。

设置时适用此参数Filter specification至系数andInternal allpass structure至Wave Digital Filter。

分支2的最后一部分是一阶

When you select this check box, the last section of the second branch is treated as a first order section. This parameter applies only when you setFilter specification至系数。当第二个分支的系数在n-by-2matrix, the block ignores the second element of the last row of the matrix. The last section of the second branch then becomes a first-order section.

清除此复选框时，第二个分支的最后一部分将视为二阶部分。当第二个分支的系数在n-by-1矩阵，块忽略了此参数。

By default, this check box is cleared.

输入高通子带

When you select this check box, the block acts as a synthesis filter bank. The block accepts two inputs to synthesize: lowpass and highpass subbands. When you clear this check box, the block acts as an IIR half band interpolator and accepts a single vector or matrix as input. By default, this check box is cleared.

从输入继承样本率

当您选择此复选框时，该块从输入信号继承了其采样率。该块根据输入端口的采样时间计算样品速率。清除此复选框时，您可以在Input sample rate (Hz)。

Input sample rate (Hz)

输入样本率，指定为Hz中的标量。默认值为44100。您可以在从输入继承样本率复选框已清除。

查看过滤器响应

打开滤波器可视化工具fvtool，并显示IIR Halfband Interpolator。这response is based on the block dialog box parameters. Changes made to these parameters update FVTool.

要更新FVTool运行时的幅度响应，请修改对话框参数，然后单击申请。

Simulate using

运行的模拟类型。您可以将此参数设置为：

  • Code generation(default)

    Simulate model using generated C code. The first time you run a simulation, Simulink®generates C code for the block. The C code is reused for subsequent simulations, as long as the model does not change. This option requires additional startup time but provides faster simulation speed thanInterpreted execution。

  • Interpreted execution

    使用MATLAB模拟模型®口译员。此选项缩短启动时间，但模拟速度比Code generation。

Supported Data Types

港口 Supported Data Types

Input

  • Double-precision floating point

  • Single-precision floating point

输出

  • Double-precision floating point

  • Single-precision floating point

也可以看看

dsp.iirhalfbandinterpolator DSP系统工具箱
dsp.IIRHALFBANDDECERATOR DSP系统工具箱
IIR半乐队删除器 DSP系统工具箱
FIR Halfband Interpolator DSP系统工具箱
FIR半带删除器 DSP系统工具箱

Algorithms

This block brings the capabilities of thedsp.iirhalfbandinterpolatorSystem Object™到Simulin金宝appk环境。

有关此块使用的算法的信息，请参阅Algorithmssection ofdsp.iirhalfbandinterpolator。

扩展功能

C/C++ Code Generation
使用Simulink®Coder™生成C和C ++代码。金宝app

版本历史记录

Introduced in R2015b