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Thread Subject:
DFT,SIGNAL PROCESSING, BANDLIMITATION,SAMPLING

Subject: DFT,SIGNAL PROCESSING, BANDLIMITATION,SAMPLING

From: kk KKsingh

Date: 19 Feb, 2010 08:20:08

Message: 1 of 3

Well I am posting this again! In last thread i made things hosh posh ..my apologies for that
m=-M:M; number of frequency points

X=2pi/deltak; Period

deltak=2pi/N*deltax;
deltax=spacing in time domain

 X(omega) = sum(n=0,N-1){ x(n) * exp(j*m*2pi/deltax*x(n) }*deltax_{n}

X(omega)= Frequency spectra
x(n)=sample locations
deltax_{n}=l_{n+1}-l_{n}
l_n=x_{n}+x_{n-1}/2; % mid point between two samples
deltax_{n}=x_{n+1}-x_{n-1}

Also it is given in the book that regular sampling in k f implies periodic sampling in time.
x_{-1}=x_{N-1}-X;
x_{N}=x_{0}+X;

This is algorithm they are applying for irregular sampling. I am not able to code it. I tried but getting error till now.

ps: _{n} DENOTES THE subscript
Thanks

kk

Subject: DFT,SIGNAL PROCESSING, BANDLIMITATION,SAMPLING

From: kk KKsingh

Date: 19 Feb, 2010 09:28:06

Message: 2 of 3


Question which is comming in my mind is for these two lines! Also it is given in the book that regular sampling in k f implies periodic sampling in time.
 x_{-1}=x_{N-1}-X;
 x_{N}=x_{0}+X;

As far i know X is X= Max(t)-min(t). If maximum time is 1 and minimum is zero then my period should be 1 correct me if i am wrong!

Now IF I HAVE 10 samples then i should have 10 deltax_{n} where n=0:9...
but problem is for t(1) what should be my deltax assuming t(0)=0
so t(0+1)+t(0-1)/2
suppose t(1)=0.1
t(-1)=t(10)-1=0;
thus deltax_1 here is 0.1*0.5=0.05

I think i am right till now...........Any comments readers will let every body know the results once i will be through it
Thanks

kk




"kk KKsingh" <akikumar1983@gmail.com> wrote in message <hllhjo$ko9$1@fred.mathworks.com>...
> Well I am posting this again! In last thread i made things hosh posh ..my apologies for that
> m=-M:M; number of frequency points
>
> X=2pi/deltak; Period
>
> deltak=2pi/N*deltax;
> deltax=spacing in time domain
>
> X(omega) = sum(n=0,N-1){ x(n) * exp(j*m*2pi/deltax*x(n) }*deltax_{n}
>
> X(omega)= Frequency spectra
> x(n)=sample locations
> deltax_{n}=l_{n+1}-l_{n}
> l_n=x_{n}+x_{n-1}/2; % mid point between two samples
> deltax_{n}=x_{n+1}-x_{n-1}/2
>
> Also it is given in the book that regular sampling in k f implies periodic sampling in time.
> x_{-1}=x_{N-1}-X;
> x_{N}=x_{0}+X;
>
> This is algorithm they are applying for irregular sampling. I am not able to code it. I tried but getting error till now.
>
> ps: _{n} DENOTES THE subscript
> Thanks
>
> kk

Subject: DFT,SIGNAL PROCESSING, BANDLIMITATION,SAMPLING

From: kk KKsingh

Date: 19 Feb, 2010 10:27:03

Message: 3 of 3


Question which is comming in my mind is for these two lines! Also it is given in the book that regular sampling in k f implies periodic sampling in time.
 x_{-1}=x_{N-1}-X;
 x_{N}=x_{0}+X;

As far i know X is X= Max(t)-min(t). If maximum time is 1 and minimum is zero then my period should be 1 correct me if i am wrong!

Now IF I HAVE 10 samples then i should have 10 deltax_{n} where n=0:9...
but problem is for t(1) what should be my deltax assuming t(0)=0
so t(0+1)+t(0-1)/2
suppose t(1)=0.1
t(-1)=t(10)-1=0;
thus deltax_1 here is 0.1*0.5=0.05

I think i am right till now...........Any comments readers will let every body know the results once i will be through it
Thanks

kk




"kk KKsingh" <akikumar1983@gmail.com> wrote in message <hllhjo$ko9$1@fred.mathworks.com>...
> Well I am posting this again! In last thread i made things hosh posh ..my apologies for that
> m=-M:M; number of frequency points
>
> X=2pi/deltak; Period
>
> deltak=2pi/N*deltax;
> deltax=spacing in time domain
>
> X(omega) = sum(n=0,N-1){ x(n) * exp(j*m*2pi/deltax*x(n) }*deltax_{n}
>
> X(omega)= Frequency spectra
> x(n)=sample locations
> deltax_{n}=l_{n+1}-l_{n}
> l_n=x_{n}+x_{n-1}/2; % mid point between two samples
> deltax_{n}=x_{n+1}-x_{n-1}/2
>
> Also it is given in the book that regular sampling in k f implies periodic sampling in time.
> x_{-1}=x_{N-1}-X;
> x_{N}=x_{0}+X;
>
> This is algorithm they are applying for irregular sampling. I am not able to code it. I tried but getting error till now.
>
> ps: _{n} DENOTES THE subscript
> Thanks
>
> kk

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