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There is a simple code in below that I prepared for understandable a question. My purpose is recover original complex signal after FFT process in Matlab.

As you understand from code, I created 1x128 complex vector. After I implement IFFT process this code. Then again I implemented FFT process for recover original complex code.

Code:

a1 = linspace(0.1,0.6,128); 
a2 = linspace(0.2,0.6,128); 
cn = complex (a1,a2); ifcn = ifft(cn,128,2); 
fcn = fft(ifcn,128,2); 
%difcn = fcn - cn;%Checking difference between original and after fft

There are few questions in my mind.

-Is ıt possible recover original complex signal after IFFT and FFT, If it is possible please could you describe me?

-In my project code normally has more deatils also I will implement after IFFT AWGN noise to signal. If this code works properly I am thinking use the this code.

Thanks in Advance

Pales

PALES
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    Can you get the exact data back? No, there are floating-point rounding errors. Can you get the original data back within a small margin or error? Yes, certainly. And you already accomplished that: `max(abs(difcn))` gives me `1.6653e-16`. That is pretty small. Why would you worry about that difference? Numbers in a computer are never exact! – Cris Luengo Jul 12 '18 at 19:19
  • on the left is input image (checkerboard) where I parse each pixel and synthesize the IFFT into its audio equivalent ... from that audio I take its FFT and generate an output image here on right ... surprising fidelity to recover original sigal I'd say https://drive.google.com/file/d/16PyAz_H2LE-4KeaLkk8fqiu9Tq33ttVX/view?usp=sharing – Scott Stensland Jul 13 '18 at 15:27
  • Thanks Cris Luengo, It was subject that I am thinking, bu I was not sure. I will go on this way for complete project. In this case It looking I have to use filter for closing real condition. – PALES Jul 13 '18 at 19:39
  • Thanks Scott Stensland, yes it is looking some floating after FFT. I understand that after FFT it means that passed to Frequency Domain from Time domain, some flotings are normal. We can not cover original signal completely. – PALES Jul 13 '18 at 19:45
  • note to PALES ... in comments you need to type in @ symbol followed by first letter or so of whoever you wish to send the comment to ... followed by tab to auto complete populating that persons accountname ... only the person asking the question will get auto notified when leaving out this @xxx technique – Scott Stensland Jul 17 '18 at 18:33
  • Thanks for your remember, but I can not use @xxx form. – PALES Jul 18 '18 at 18:43

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