How can I apply a FFT moving window ?

hello,

i have a signal (x) as a vector (1*1799), the sampling frequency Fs=30 and Ns=1799

how can I apply a FFT mobile window on 100 samples each time along the signal

thank you

Answer 1

[Walter Roberson]

buffer() and fft()

see also spectrogram()

[djamaleddine djeldjli]

I thank you for your responsiveness

i need to work on the signal 100 samples by 100 samples so for each 100 samples I compute the FFT to use its max pick frequency in passband filtering

[Walter Roberson]

fft(buffer(TheSignal,100))

[djamaleddine djeldjli]

i tried it, the result is a matrix

but i need a moving window to apply ether the FFT and also filtering on signal vector (1x1799)

[Walter Roberson]

when you do the moving window fft how many samples at aa time do you move the window ahead by ..? If you had 200 samples would that be 2 windows of 100 samples each or would it be a window 1:100 a second 2:101, so on to 101:200 for aa total of 101 windows processed ?

Anyway you still fft(buffer ). you just adjust the overlap parameter to buffer. you search the max for each column. Somehow you use the information for your passband filtering though I cannot think why you would be interested in the max.

[djamaleddine djeldjli]

how many samples at a time depends on the Fs for me i need to apply FFt on 100 samples and i move the window with 60 samples

the width of the window is 100s

ant it moves by 60s

[Walter Roberson]

buffer is still the solution .