OFDM DA conversion problem I'm working on a sound card based OFDM system and ran into some problems:



How can I perform  DAC on the real and imaginary parts of the IFFT? I think they are real numbers instead of 0 and 1. Thanks.
Imaginary part of a complex number is real. For example

$$z = 1 - 2j$$
$$\mathsf{Re}(z) = 1$$
$$\mathsf{Im}(z) = -2$$

The same will happen with the imaginary part of your FFT. In the end, you get two real signals. Then you modulate them by two sinusoids which are 90 degrees out of phase, and add the modulated signals at the output stage.