802.11a Sub Carriers

[gilmo]

Hello all!

I was wondering if you have the correct information regarding the number of sub-carriers in the OFDM modulation scheme.

The RF design magazine says 52 for 802.11a and Jim Geier who writes articles for 80211 Planet wrote that OFDM has 48 sub-carriers. So please let me know the correct information or if both are correct when should I apply one or another.

Regards,

Gilmo

[Phoenix]

There are 52 total sub-carriers. 48 are used for data and 4 are pilot tones used for phase orientation of the signal at the reciever.