averaging FFT bins????

[bigstrik]

hi .... i'am working on a matlab code for energy detection technique ..... during reading thesis on this topic i found that to detect the signal in frequency domain,we use FFT. the part that i didn't understand is " averaging M bins L times" . what does it mean??? what is M and L?? and how can divide N-point FFT to M bins ????

 

[Mityan]

Maybe M bins that together represent the band of interest (in case of superresolution)? And L times is arbitrary value?

 

[bigstrik]

dear Mityan , this is the block diagram where i found the block of " averaging M bins L times"
**broken link removed**

so, what is M and L? and how can i evaluate them in matlab?
thank you in advance.

 

[Mityan]

In MATLAB there is just a sum of L consequent fft results. M - if my suggestion is true, just take from fft result of length K. 0...M-1 or 5...M+4 for example. This is dependent on lower frequency of band of interest. Total K bins of fft result are from 0 to fs (sampling frequency) with the fs/K step.

 

[bigstrik]

thanx Mityan for your reply ..... the main aim i want to achieve is to use this block diagram to get the energy of the signal in the frequency domain .... and must be equal to the energy in the time domain ... and that's not satisfied with me ??