The OFDM symbol duration is equal to FFT size (number of subcarriers) and guard interval according to some textbooks. However, in some research papers they mention that they implemented (using matlab) the symbol duration to be equal for example 12 µs, which is equal to 1/delta_f. The first scenario can be implemented easily, while the other one is confusing a little bit. My question is how we can generate an ofdm signal (in matlab) with a symbol duration equal to a value in µs (e.g., 10 µs , 12 µs, etc.)?
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The time duration of each encoded symbol is $1/\Delta F$ but the time duration used to transmit each symbol is extended by the CP. So both results are valid as far as time duration for each symbol, but you must clarify if you are referring to the duration of data going into the IFFT block in the transmitter or the duration of that data after IFFT with the CP added.
In effect consider each subcarrier as a rectangular pulse shaped QAM modulated symbol of duration $1/\Delta F$ that goes to zero in between symbols.
answered Mar 30, 2022 at 21:01
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$\begingroup$ Thanks for clarifying! I am using the OFDM matlab function to generate the OFDM symbol, but how can I determine the subcarrier spacing (delta_f) using that function? $\endgroup$ Commented Mar 30, 2022 at 22:14
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$\begingroup$ Never used it- I do it in Python. $\endgroup$ Commented Mar 30, 2022 at 22:17
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$\begingroup$ Okay, I also have never used python $\endgroup$ Commented Mar 30, 2022 at 22:19
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