Hi All,
        After long time,i am back with a question.

For a 5MHz bandwidth LTE DL, there are around 211 guard subcarriers
(sum of both right and left guard carriers) (in DL OFDMA) and in
wimax, for same 5MHZ bandwidth, there are 92 guard subcarriers (sum of
both right and left guard carriers).

in LTE, subcarriers are at distance of 15khz, whereas it is 10.9375
khz in wimax.

i didnt see any reason why they should leave so many guard carriers in
LTE wasting precious spectrum (for adjacent channel interference, i
think around 100 subcarriers(sum of both right and left guard
carriers) would have been appropriate)

is there any strong reason in LTE (to leave 210 subcarriers for guard
carriers) to do so.

Regards
Particlereddy

> For a 5MHz bandwidth LTE DL, there are around 211 guard subcarriers
> 
> (sum of both right and left guard carriers) (in DL OFDMA) and in
> 
> wimax, for same 5MHZ bandwidth, there are 92 guard subcarriers (sum of
> 
> both right and left guard carriers).
> 
> 
> 
> in LTE, subcarriers are at distance of 15khz, whereas it is 10.9375
> 
> khz in wimax.
> 
> 
> 
> i didnt see any reason why they should leave so many guard carriers in
> 
> LTE wasting precious spectrum (for adjacent channel interference, i
> 
> think around 100 subcarriers(sum of both right and left guard
> 
> carriers) would have been appropriate)
> 
> 
> 
> is there any strong reason in LTE (to leave 210 subcarriers for guard
> 
> carriers) to do so.

Did you find an answer to this question?

The original question is incorrect. 
It refers to the typical FFT size of 512, should use the channel spacing
instead:
512 x 15kHz would be 7.68MHz, the channel spacing in LTE5 is 5 MHz.