how remove the effect of hermitian symmetric ???

To remove the imaginary signal a hermitian symmetry is placed with the ifft as shown below

Xsym = ifft(Y,'symmetric')

My question is how to remove it in fft?

[David Goodmanson]

Hi abdullah,

do you mean removing it if all you have is Xsym? That would not be possible because of loss of information when using the 'symmetric" optiion.

[abdullah qasim]

Yes, this is true, but should be used in the transmission system, but in the reception must remove its effect

Answer 1

[Matt J]

This is equivalent to forcing conjugate symmetry in fft(),

 Yfft = ifft(conj(Y),'symmetric')*numel(Y);

If Y is real, you can of course omit the conj.

[abdullah qasim]

sorry not working

[Matt J]

Works fine for me:

>> Y=ifftshift([1.1 2.1 3 2 1])  %non-symmetric input

Y =

    3.0000    2.0000    1.0000    1.1000    2.1000

>> Ysym=round(Y)  %symmetric input

Ysym =

     3     2     1     1     2

>> fft(Ysym)   %ideal result

ans =

    9.0000    2.6180    0.3820    0.3820    2.6180

>> Yfft = ifft(conj(Y),'symmetric')*numel(Y)  %force symmetry

Yfft =

    9.0000    2.6180    0.3820    0.3820    2.6180