>
> In many OFDM system(like 802.11a and DVB-T), they always padding zeros
> to data before go to the IFFT module. Why use padding zeros?
They're known as virtual sub-carriers (or null sub-carriers).
Essentially, they cause the baseband time-domain signal (post-IFFT) to
be oversampled, which makes the job of the DAC easier.
--
Oli
Reply by Davy●April 15, 20062006-04-15
Hi all,
In many OFDM system(like 802.11a and DVB-T), they always padding zeros
to data before go to the IFFT module. Why use padding zeros?
Best regards,
Davy