Hi Ranjeet,
I think the answer will be as possible
The subcarrier frequencies are integer multiples of 1/Tsymbol, where Tsymbol is the duration of an OFDM symbol.
And in OFDM the component allows the introduction of a cyclic extension of the symbol transmitted
or a guard time with zero transmission. The parameter Number of prefix points will
define how many points will be used in the guard period.
For examples if the global bit rate is 40Gbit/ and a QPSK modulation (2 bits per symbol), the symbol rate will
be 20Gsym/s. In both cases there are a total of 128 sub-carriers available such that:
OFDM symbol period = Symbol period * 128 = 128/(Symbol rate) = 2 * 128 /Global bit
rate.
Thanks,