Reply by oren_i June 15, 20062006-06-15
Hello
I'm trying to perform Channel Estimation on an OFDM signal by using
various interpolation techniques between pilot symbols.

The best method is to implement an interpolation filter (in the time
domain, or in the freq domain using FFT).

The problem is that in order to achieve a "good" FIR interpolation filter,
the filter must be quite long. 

Because of the long filter length (long tail)  => I can't estimate
properly the channel on the edges of the signal.

If I would be able to use an IIR filter (short length) with linear phase,
I can pass the signal through the filter in both directions (the forward
and backward) and get the best result at the edges of the signal.

1)	Is there method to build an IIR interpolation filter with linear phase

2)	Is there an alternative method to solve the above problem

Thanks,

oren