>My guess is it's to provide maximum separation from the short training
>sequence. Since T1 and T2 are the same thing you don't need a guard
interval
>for them, but you would have problems if t1-t10 bled over into the long
>preamble.
>
>-Clark
>

Yes, you are correct, thank you very much!!

"ofdm2006" <qjqflash@hotmail.com> wrote in message
news:ENOdncwFuMRYl4fZnZ2dneKdnZydnZ2d@giganews.com...
> I have a question that why in 802.11a IEEE standard, the PLCP long
training
> sequence takes the GI2(Guard interval 2) as the prefix of two OFDM
symbols,
> not one GI before one OFDM and the other GI before the second OFDM symbol?
> What is the advantage of that??
>
> The following includes the IEEE 802.11a 1999 version:
> http://standards.ieee.org/getieee802/802.11.html
>
> Thanks.
>
>

My guess is it's to provide maximum separation from the short training
sequence. Since T1 and T2 are the same thing you don't need a guard interval
for them, but you would have problems if t1-t10 bled over into the long
preamble.

-Clark

I have a question that why in 802.11a IEEE standard, the PLCP long training
sequence takes the GI2(Guard interval 2) as the prefix of two OFDM symbols,
not one GI before one OFDM and the other GI before the second OFDM symbol?
What is the advantage of that??

The following includes the IEEE 802.11a 1999 version:
http://standards.ieee.org/getieee802/802.11.html

Thanks.