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年代hort-Time FFT

使用短时，快速傅立叶变换（FFT）方法的非参数估计值

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DSPXFRM3

  • 年代hort-Time FFT block

Description

The Short-Time FFT block computes a nonparametric estimate of the spectrum. The block buffers, applies a window, and zero pads the input signal. The block then takes the FFT of the signal, transforming it into the frequency domain.

Connect your single-channel analysis window to the w(n) port. For the分析窗口长度parameter, enter the length of the analysis window,W。块缓冲输入信号，使其具有框架长度W

将单渠道或多通道输入信号连接到X（n）端口。块缓冲和窗口此信号之后，它在计算FFT之前将信号零填充。为了FFT lengthparameter, enter the length to which the block pads the input signal. For theOverlap between consecutive windows (in samples)parameter, enter the number of samples to overlap each frame of the input signal.

The block outputs the complex-valued, single-channel or multichannel short-time FFT at port X(n,k).

定点数据类型

The following diagram shows the data types used within the Short-Time FFT subsystem block for fixed-point signals.

上图中数组矢量倍数块的定点参数的设置如下：

  • Rounding Mode—地面

  • 年代aturate on integer overflow—Wrap

  • Product output—Inherit via internal rule

  • Accumulator—Inherit via internal rule

  • Output—年代ame as first input

The settings for the fixed-point parameters of the FFT block in the diagram above are as follows:

  • Rounding Mode—地面

  • 年代aturate on integer overflow—Wrap

  • 年代ine table—年代ame word length as input

  • Product output—Inherit via internal rule

  • Accumulator—Inherit via internal rule

  • Output—Inherit via internal rule

年代ee theFFT和Array-Vector Multiplyblock reference pages for more information.

Examples

Thedspstsaexample illustrates how to use the Short-Time FFT and Inverse Short-Time FFT blocks to remove the background noise from a speech signal. To open thedspstsamodel, typedspstsa在matlab中®command prompt.

Parameters

分析窗口长度

年代pecify the frame length of the analysis window. The分析窗口长度must be a positive integer value greater than one.

Overlap between consecutive windows (in samples)

Enter the number of samples of overlap for each frame of the input signal.

FFT length

Enter the length to which the block pads the input signal.

年代upported Data Types

Port 年代upported Data Types

x(n)

  • 双精度浮点

  • 单精度浮点

  • Fixed point (signed only)

  • 8-, 16-, and 32-bit signed integers

w（n）

  • 双精度浮点

  • 单精度浮点

  • Fixed point (signed only)

  • 8-, 16-, and 32-bit signed integers

X(n,k)

  • 双精度浮点

  • 单精度浮点

  • Fixed point (signed only)

  • 8-, 16-, and 32-bit signed integers

参考

[1] Quatieri, Thomas E.Discrete-Time Speech Signal Processing.Englewood Cliffs, NJ: Prentice-Hall, 2001.

Extended Capabilities

版本历史

Introduced before R2006a

年代ee Also

Objects

Blocks

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