Real OFDM Signal Generation

[Gokul Boro .]

Hi all,
I want to design an OFDM system with Hermitian symmetry. It is seen that it can be done with OS12 OFDM block. Since hermitian symmetry produces real valued OFDM signals, can the second terminal of the OFDM block be ignored? Will this work? Also in the receiver how do I view the constellation? Since there is no imaginary part it will not be possible to view it. Now can I design a system to view it at the receiver. Please give me some idea.

Can Frequency domain Hilbert transform based OFDM system be designed in Optisystem?

Thank you.

[alistu]

Hi Gokul,

You have mentioned in your post that it is seen that OFDM system with Hermitian symmetry can be done with OS12 OFDM blocks. Can you please give a reference or elaborate more on this?

As far as I know, the only transform available in OptiSystem OFDM components is FFT. You might want to use Matlab component for your purpose.

Regards

[Gokul Boro .]

Hi alistu,
I saw that hermitian symmetry can be done with OS12 block from the description of OFDM block. When I looked into the parameters of the block in the help section I saw that the “symmetric spectrum” in the parameters meant “Defines if the input vector to the IFFT is constrained to have hermetian symmetry”.
Thank you Alistu.

[alistu]

Thank you for your explanation. I will get back to you as soon as I find a way. However, as for what you have mentioned about the second terminal being ignored, I don’t think this can be possible, as the second terminal corresponds to some information which will be lost in case of being ignored.

Regards

[Gokul Boro .]

Thanks for your concern.
As the input is having hermitian symmetry, there is no imaginary part. Now, if the output terminals of OFDM block outputs real and imaginary parts in the 1st and 2nd terminal, then how can I get the imaginary signal if the input is having hermitian symmetry? I don’t know whether my knowledge is in right track or not, since I am new in the field of communication.
Thank you once more

[Fariza Farhat]

Hi, I am having the same problem. Can you suggest how to get a real time wave?

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