Hi all,
I am kind of new to OFDM architecture. So, why do ppl use IFFT at tx? I tried with FFT at tx on a simulation platform, it seems to work. The only difference between IFFT and FFT is in the phase. Is it? Or am I just plain dumb? Can suggest good materials to explain this?
m an DSP engineer...working on Wimax Phy...
actually..you both are totally wrong...
after constelletion mapping ...signal converted into freq. domain..so IFFT used to send information on subcarriers..
find this paper here..picture will become more clearer...
It all starts from the OFDM formula....
Σ(QAM/PSK symbol)e^jωt.......
It suggest us to take IFFT ....
yes obviously the definition of fourier trans is not fixed...and u can use either way.....but then u should reason out in case of your question...