I had a question about normalizing OFDM transmit power after IFFT across each subcarrier. I have simulated OFDM with BPSK and according to different website I have used
x is the modulated signal and
NFFT is the size of
Nsubcarrier_used is total number of subcarrier that is used. This gives me the transmit power of $1$ across each subcarrier.
My question is: How to know the scaling factor, such as
NFFT/sqrt(Nsubcarrier_used), of different modulation schemes?
Because I have tried the same scaling factor for 16-QAM here and it did not give me $1$ as a transmit power. Therefore I would really appreciate if anyone can explain about the method to find the scaling factor for FFT and IFFT in OFDM.