OFDM using DSP Builder

Hi zeep25,

I just wanted to tell you that any kind of QPSK mapping (after appropriate scaling) will lead you to send to each channel of the IFFT block a +[quantity] and a -[quantity]. In order to maximize your IFFT output (exploit the whole dynamic range) you may simple send your ones and zeros as the maximum and minimum possible values depending on the chosen resolution.

Example: if your IFFT input is 8-bits wide, an the values are unsigned, the zero will be 0x00 and the maximum will be 0x11. Of course take care if using 2s complement notation, these values must be converted into 2s complement.

The IFFT output can be scaled if its amplitude must be changed depending of what is around your IFFT.

Maybe I've synthesized my idea in a too short way...

Cheers

OD