DFT circular convolution

Started by October 11, 2007
hello everybody!!
can anyone tell me in calculating circular convolution using DFT
what will happen if i use two different length signal?
suppose one is of 4 point and the other is of 3 point then what will be
the system?i have to do both 4 point DFT?or 4+3-1 or 6 point DFT as like
linear convolution...
plz help me out..
shatila

shatila wrote:
> hello everybody!! > can anyone tell me in calculating circular convolution using DFT > what will happen if i use two different length signal? > suppose one is of 4 point and the other is of 3 point then what will be > the system?i have to do both 4 point DFT?or 4+3-1 or 6 point DFT as like > linear convolution... > plz help me out.. > shatila
Well, as you should know, convolution using a DFT is done by multiplying the (complex) values of each DFTed signal. If you want to do that with two signals of different length with no prior padding, some values of your longer signals won't find any match for multiplication. I suggest you to read more about it on relevant chapters on http://www.dspguide.com
"Michel Rouzic" <Michel0528@yahoo.fr> wrote in message