Could u please explain howdo we do channel estimation using pilot symbols?

[mazdaspring]

1)Pilots we are inserting in between data subcarriers and they are not modulated.
Whether we need to extract the pilots from data after FFT operation or is there any process ?

2)After extraction what we are doing for estimating the channel?

Thank you so much.

 

[Mityan]

'Cause OFDM applications are wideband, uniformly spreaded pilots (which are transmitted with the definite level) show us on receiver side some kinda channel frequency response.
So we can adjust the equalizer.

Sure these pilots should be eliminated from data no way but after FFT