Hi, Could anyone give solution to this problem ? Write a program to compute the 128 point FFT for the signal, x(n) = cos(n *pi)/2.Also plot the FFT spectra. any pointer would be helpful Thanks Pramod
A problem on FFT
Started by ●December 19, 2004
Reply by ●December 19, 20042004-12-19
pramodchowda@gmail.com wrote:> Hi, > > Could anyone give solution to this problem ? > > Write a program to compute the 128 point FFT for the signal, x(n) = > cos(n *pi)/2.Also plot the FFT spectra. > any pointer would be helpful > > Thanks > Pramod >But you only have one frequency? f=1/4 cycle/sample so that is your spectra. you can use matlab fft(). are you being asked to code fft function itself from scratch?
Reply by ●December 19, 20042004-12-19
pramodchowda@gmail.com wrote:> Hi, > > Could anyone give solution to this problem ? > > Write a program to compute the 128 point FFT for the signal, x(n) = > cos(n *pi)/2.Also plot the FFT spectra. > any pointer would be helpful > > Thanks > PramodHomework? Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●December 19, 20042004-12-19
"Fred" <Fred@nowhere.com> wrote in message news:Ghfxd.495$yV1.279@newssvr14.news.prodigy.com...> pramodchowda@gmail.com wrote: > > > Hi, > > > > Could anyone give solution to this problem ? > > > > Write a program to compute the 128 point FFT for the signal, x(n) = > > cos(n *pi)/2.Also plot the FFT spectra. > > any pointer would be helpful > > > > Thanks > > Pramod > > > > But you only have one frequency? > > f=1/4 cycle/sample > > so that is your spectra. > > you can use matlab fft(). are you being asked to code fft function > itself from scratch?Could be the trick question to encourage "thinking before coding".
Reply by ●December 19, 20042004-12-19
> But you only have one frequency? > > f=1/4 cycle/sample > > so that is your spectra.The signal is windowed by a 128 sample long window, this will make the FFT different from a single frequency value.
Reply by ●December 19, 20042004-12-19
Reply by ●December 20, 20042004-12-20
On 19 Dec 2004 19:05:13 -0800, "S A kumar" <arun.sakumar@gmail.com> wrote:>Is Google groups turning into some sort of online homework assistance?Or something like that. I have noticed that the quality of some the questions is going way down, close to the point of handholding. I get the impression that some folks are posting questions before even thinking about it enough to frame the question clearly. It is a little tough sometimes to assess how much of that is due to a language barrier, though. Eric Jacobsen Minister of Algorithms, Intel Corp. My opinions may not be Intel's opinions. http://www.ericjacobsen.org
Reply by ●December 20, 20042004-12-20
<pramodchowda@gmail.com> wrote in message news:1103459121.614956.308770@f14g2000cwb.googlegroups.com...> Hi, > > Could anyone give solution to this problem ? > > Write a program to compute the 128 point FFT for the signal, x(n) = > cos(n *pi)/2.Also plot the FFT spectra. > any pointer would be helpful > > Thanks > Pramod >Hi Pramod your input signal is a repetition of -0.5 , +0.5 to fill yor fft ( or +0.5, -0.5 if you start with n=0). Best of luck - Mike
