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What is difference between OFDM and GFDM?

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engineer_eda

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Hi,

I am trying to understand the difference(s) between OFDM and GFDM which are
used as a multicarrier modulation techniques in wireless communication. As
far as I know the OFDM uses the orthogonal subcarriers and the GFDM is with
the non-orthogonal subcarriers when designing a transmitter. The GFDM is possibly going to be the modulation technique for 5G systems as it has been discussed in a research area.

Could anyone please explain further about GFDM design and its differences from OFDM?
What is the purpose of using GFDM when designing a transmitter? The subcarriers are created just after the IFFT?

In GFDM, how does the IFFT block work when creating the subcarriers?

What about the subcarrier pulse shaping in GFDM?

Thanks in Advance!
 

kapez

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Generalized Frequency Division Multiplexing- GFDM

- no ortogonality
- use digital bank of filter
- use cyclic prefix CP (tail biting)

::plus::
- output spectrum is very weak radiation out specified frequency band
- significantly smaller PAPR
- better energy balance of transmission
- simpler equalization at the receiver side
GFDM_Tx.png
:-:Block diagram of the transmitter:-:
- new bloks are: bank of filter -> digital filtering
- the transmitter contains processor for IFFT
 

engineer_eda

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Thank you Kapez! Do you know why oversampling is performed after CP?
 
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