Mesures spectrales

Puissance du canal, bande passante, fréquence moyenne, fréquence médiane, distorsion harmonique

Utilisez obw et powerbw pour trouver la bande passante occupée à 90 % et la bande passante à 3 dB d’un signal. Calculez la fréquence moyenne ou médiane d’un spectre de puissance. Estimez la puissance sur une bande de fréquence donnée. Mesurez la distorsion harmonique. Estimez la bande passante instantanée, la fréquence instantanée, l’entropie spectrale et le kurtosis spectral.

Fonctions

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Puissance et bande passante

`bandpower`	Band power
`enbw`	Equivalent noise bandwidth
`instbw`	Estimate instantaneous bandwidth (depuis R2021a)
`instfreq`	Estimate instantaneous frequency
`meanfreq`	Mean frequency
`medfreq`	Median frequency
`obw`	Occupied bandwidth
`powerbw`	Power bandwidth
`spectralCrest`	Spectral crest for signals and spectrograms
`spectralEntropy`	Spectral entropy for signals and spectrograms
`spectralFlatness`	Spectral flatness for signals and spectrograms
`spectralKurtosis`	Spectral kurtosis for signals and spectrograms
`spectralSkewness`	Spectral skewness for signals and spectrograms
`signalFrequencyFeatureExtractor`	Streamline signal frequency feature extraction (depuis R2021b)
`signalTimeFrequencyFeatureExtractor`	Streamline signal time-frequency feature extraction (depuis R2024a)

Mesures harmoniques

`sfdr`	Spurious free dynamic range
`signalTimeFeatureExtractor`	Streamline signal time feature extraction (depuis R2021a)
`sinad`	Signal to noise and distortion ratio
`snr`	Signal-to-noise ratio
`thd`	Total harmonic distortion
`toi`	Third-order intercept point

Rubriques

Measure the Power of a Signal
Estimate the width of the frequency band that contains most of the power of a signal. For distorted signals, determine the power stored in the fundamental and the harmonics.
Measure Total Harmonic Distortion
Measure the total harmonic distortion of a sinusoidal signal.

Sélection d՚exemples

Analyze Harmonic Distortion

Analyze the harmonic distortion of a weakly nonlinear system in the presence of noise.

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Spurious-Free Dynamic Range (SFDR) Measurement

Measure the SFDR of a numerically controlled oscillator and explore the effects of adding phase dither.

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Measure Signal Similarities

Compare signals with different sample rates or frequency content, measure delays, and determine if there is a signal in a measurement.

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Audio Device Test Stimuli

Exercise a nonlinear system with common audio device stimuli and compare the advantages and disadvantages of the different stimuli.

(Audio Toolbox)