变换
DSP System Toolbox™ 提供多个 System object 和模块，用于将域流信号变换为频域信号，反之亦然。诸如快速傅里叶变换 (FFT)、短时傅里叶变换、高分辨率 FFT、小波变换以及对应的逆运算等方法，使您能够在任一域中分析信号，并可广泛应用于多个领域。有关示例，请参阅Analyze a Subband of Input Frequencies Using Zoom FFT。有关此主题的 MathWorks® 教学课程模块，请参阅傅里叶分析（MathWorks 教学资源）。
DSP System Toolbox 还提供 Wavelet Scattering 模块，该模块创建了一个框架，用于在 Simulink® 环境中实现小波时间散射。使用此模块从实数值数据中推导低方差特征，然后在机器学习和深度学习应用中使用这些特征。有关详细信息，请参阅Wavelet Scattering (Wavelet Toolbox)。Wavelet Scattering 模块需要 Wavelet Toolbox™。
对象
dsp.FFT | Discrete Fourier transform |
dsp.IFFT | Inverse discrete Fourier transform (IDFT) |
dsp.ISTFT | Inverse short-time FFT |
dsp.STFT | Short-time FFT |
dsp.ZoomFFT
| High-resolution FFT of a portion of a spectrum |
模块
主题
- Transform Time-Domain Data into Frequency Domain
This example shows how to transform time-domain data into the frequency domain using the FFT block.
- Transform Frequency-Domain Data into Time Domain
When you want to transform frequency-domain data into the time domain, use the IFFT block.
- Linear and Bit-Reversed Output Order
Learn the meaning of linear and bit-reversed data order as used by the FFT and IFFT blocks.
- Analyze a Subband of Input Frequencies Using Zoom FFT
Compute the zoom FFT of a sine wave in Simulink.
- Speech Enhancement with Gain in Frequency Domain
Denoise a signal by applying selective gain on the signal in the frequency domain. Convert the denoised signal back into time domain and play the signal using Audio Device Writer.
- Variable-Size Signal Support DSP System Objects
List of System objects that support variable-sized signals in DSP System Toolbox.
精选示例
Zoom FFT
Showcases zoom FFT, which is a signal processing technique used to analyze a portion of a spectrum at a high resolution. DSP System Toolbox™ offers this functionality in MATLAB® through the dsp.ZoomFFT System object™, and in Simulink® through the Zoom FFT block in the DSP System Toolbox library.
Detect Air Compressor Sounds in Simulink Using Wavelet Scattering
Use the Wavelet Scattering block and a pretrained deep learning network to classify audio signals.
Detect Air Compressor Sounds on a Raspberry Pi Using Wavelet Scattering and TensorFlow Lite Network
Generate and deploy Raspberry Pi® code to detect air compressor sounds using the Wavelet Scattering Simulink block and a pretrained deep learning network.
Detect Anomalies in ECG Data Using Wavelet Scattering and LSTM Autoencoder in Simulink
Use wavelet scattering and deep learning network to detect anomalies in ECG signals.
