I am trying to understand how SC-FDMA is used in LTE system. Every description I found so far refers to DFT and IDFT. However, when I checked 3GPP TS 36.211 chapter 5.4 (SC-FDMA baseband signal generation) and 6.12 (OFDM baseband signal generation) I found that there is hardly any difference between given equations (I did not copy the equations here because they are quite long) - OFDMA takes into consideration DC subcarrier, in case of SC-FDMA term "k + 1/2" is used wheres OFDMA uses simply term "k" (k can be denoted as number of subcarrier). Moreover the document does not say anything about neither DFT nor IDFT.
In case of OFDMA, I can imagine how the given equation can be considered as IDFT. But what about SC-FDMA? It looks like that modulated symbol is mapped in between two subcarrier. Can somebody explain me this issue in details?
Best regards