OFDM using DSP Builder

Hi,

I can tell you about scaling for ifft but don't know about other signals around your ifft...I leave that to you.

for n bits scale as follows(for I or Q):

value = round(value*2^(n-1)-1)

connect I to real input, Q to imaginary input.(you may reverse that for test)

As to output: the best test is to check results numerically against Matlab function:

y=ifft(complex(I,Q)) using the same scale inputs

compare y(real and imaginary) to your output

Just a simple way to understand ofdm idea:

The mapped data is assumed in frequency domain then you do ifft to go to time domain. Remember one sinusoid in time domain corresponds to one constant value in frequency domain. So instead of generating tones in time domain you generate them in frequency domain through the ifft input vector, just put your constants or values there but needs correct spacing...each value results in one tone at the ifft output at corresponding frequency. As such ofdm can generate thousands of carriers without any NCO. and it goes on....the point here is one carrier only modulates one symbol while in classic modulators one carrier modulates a lot of symbols. The mass of tones cancel each other due to orthogonality and one symbol per carrier is left out clean that doesn't spread around.

Kaz