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变换

傅里叶、chirp Z、DCT、Hilbert、倒频谱、Walsh-Hadamard

Signal Processing Toolbox™ 提供的函数可用于计算广泛使用的正变换和逆变换,包括快速傅里叶变换 (FFT)、离散余弦变换 (DCT) 和 Walsh-Hadamard 变换。提取信号包络并使用分析信号估计瞬时频率。在时频域中分析信号。研究幅值-相位关系,估计基频,并使用倒频谱检测频谱周期性。使用二阶 Goertzel 算法计算离散傅里叶变换。

函数

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abs绝对值和复数的模
angle相位角
fft快速傅里叶变换
ifft快速傅里叶逆变换
fftshift将零频分量移到频谱中心
dftmtxDiscrete Fourier transform matrix
fft2二维快速傅里叶变换
ifft2二维快速傅里叶逆变换
instfreqEstimate instantaneous frequency
cztChirp Z-transform
goertzelDiscrete Fourier transform with second-order Goertzel algorithm
dctDiscrete cosine transform
idctInverse discrete cosine transform
envelopeSignal envelope
fwhtFast Walsh-Hadamard transform
ifwhtInverse Fast Walsh-Hadamard transform
hilbertDiscrete-time analytic signal using Hilbert transform
emdEmpirical mode decomposition
fsstFourier synchrosqueezed transform
ifsstInverse Fourier synchrosqueezed transform
hhtHilbert-Huang transform
kurtogramVisualize spectral kurtosis
pspectrumAnalyze signals in the frequency and time-frequency domains
spectrogramSpectrogram using short-time Fourier transform
xspectrogramCross-spectrogram using short-time Fourier transforms
stftShort-time Fourier transform
istftInverse short-time Fourier transform
wvdWigner-Ville distribution and smoothed pseudo Wigner-Ville distribution
xwvdCross Wigner-Ville distribution and cross smoothed pseudo Wigner-Ville distribution
ccepsComplex cepstral analysis
iccepsInverse complex cepstrum
rcepsReal cepstrum and minimum-phase reconstruction
bitrevorderPermute data into bit-reversed order
digitrevorderPermute input into digit-reversed order

主题

离散傅里叶变换和余弦变换

离散傅里叶变换

了解数字信号处理的首要工具。

Chirp Z-Transform

Use the CZT to evaluate the Z-transform outside of the unit circle and to compute transforms of prime length.

Discrete Cosine Transform

Compute discrete cosine transforms and learn about their energy compaction properties.

DCT for Speech Signal Compression

Use the discrete cosine transform to compress speech signals.

Hilbert 变换和 Walsh-Hadamard 变换

Hilbert 变换

Hilbert 变换可用于形成解析信号。

Analytic Signal for Cosine

Determine the analytic signal for a cosine and verify its properties.

包络提取

使用 hilbertenvelope 函数提取信号的包络。

Analytic Signal and Hilbert Transform

Generate the analytic signal for a finite block of data using the hilbert function and an FIR Hilbert transformer.

Hilbert 变换与瞬时频率

使用 Hilbert 变换估计单分量信号的瞬时频率。说明该程序不适用于多分量信号。

Single-Sideband Amplitude Modulation

Perform single-sideband amplitude modulation of a signal using the Hilbert transform. Single-sideband AM signals have less bandwidth than normal AM signals.

Walsh-Hadamard 变换

了解 Walsh-Hadamard 变换,一种非正弦类正交变换方法。

Walsh-Hadamard Transform for Spectral Analysis and Compression of ECG Signals

Use an electrocardiogram signal to illustrate the Walsh-Hadamard transform.

倒频谱分析

复倒频谱 - 基频估计

使用复倒频谱来估计说话者的基频。将结果与使用过零方法获得的估计值进行比较。

倒频谱分析

应用复倒频谱以检测信号中的回声。

特色示例