Question

Short time fourier transform uses which window matlab

Answer 1

Answer:

stft

Short-time Fourier transformcollapse all in page

Syntax

s = stft(x)

s = stft(x,fs)

s = stft(x,ts)

s = stft(___,Name,Value)

[s,f] = stft(___)

[s,f,t] = stft(___)

stft(___)

Description

s = stft(x) returns the short-time Fourier transform (STFT) of x.

example

s = stft(x,fs) returns the STFT of x using sample rate fs.

s = stft(x,ts) returns the STFT of x using sample time ts.

example

s = stft(___,Name,Value) specifies additional options using name-value pair arguments. Options include the FFT window and length. These arguments can be added to any of the previous input syntaxes.

[s,f] = stft(___) returns the frequencies f at which the STFT is evaluated.

[s,f,t] = stft(___) returns the times at which the STFT is evaluated.

stft(___) with no output arguments plots the magnitude of the STFT in the current figure window. The STFT is plotted as two-sided and centered.

Examples

collapse all

3D STFT Visualization

Generate two seconds of a voltage controlled oscillator output, controlled by a sinusoid sampled at 10 kHz.

fs = 10e3;

t = 0:1/fs:2;

x = vco(sin(2*pi*t),[0.1 0.4]*fs,fs);

Compute and plot the STFT of the signal. Use a Kaiser window of length 256 and shape parameter . Specify the length of overlap as 220 samples and DFT length as 512 points. Plot the STFT with default colormap and view.

stft(x,fs,'Window',kaiser(256,5),'OverlapLength',220,'FFTLength',512);

Change the view to display the STFT as a waterfall plot. Set the colormap to jet.

view(-45,65)

colormap jet

STFT of Quadratic Chirp

Generate a quadratic chirp sampled at 1 kHz for 2 seconds. The instantaneous frequency is 100 Hz at  and crosses 200 Hz at  second.

ts = 0:1/1e3:2;

f0 = 100;

f1 = 200;

x = chirp(ts,f0,1,f1,'quadratic',[],'concave');

Compute and display the STFT of the quadratic chirp with a duration of 1 ms.

d = seconds(1e-3);

win = hamming(100,'periodic');

stft(x,d,'Window',win,'OverlapLength',98,'FFTLength',128);

Explanation: