Re: [Discuss-gnuradio] references using in ofdm_equalizer_simpledfe

Aditya, thanks your clarify !

在 2014年09月04日 21:31, Aditya Dhananjay 写道:
>
>
>
> On Thu, Sep 4, 2014 at 9:04 AM, Tiankun Hu <tiankun.hu@foxmail.com
> <mailto:tiankun.hu@foxmail.com>> wrote:
>
> Hi Martin,
> Could you tell me the reference paper that you used in
> ofdm_equalizer_simpledfe?
>
>
> ​Hello Tiankun,
>
> A decision feedback equalizer (DFE) works like this:
>
> The equalizer keeps track of the channel estimate on every subcarrier​
> i. Call this estimate H_i. The initial values of H_i are provided by the
> Schmidl-Cox block, and these values are calculated from the SYNC symbols
> present in every packet.
>
> Now, when a symbol r_i is received on subcarrier i, it is equalized
> using the estimate H_i. The equalized symbol is matched to the nearest
> constellation point. Let this symbol be R_i. Now, the new estimate of
> H_i is calculated from r_i and R_i. This new value of H_i is then used
> for the next symbol on subcarrier i.
>
> DFE works well when the channel changes slowly across time. However, if
> there is substantial residual CFO (carrier frequency offset) or Doppler,
> then errors are possible. Substantial channel variations across
> subcarrier indices is irrelevant, because DFE maintains an independent
> channel estimate H_i for each subcarrier i.
>
> Good luck with GNU Radio. :)
>
> Best,
> Aditya
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> Discuss-gnuradio@gnu.org
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>

--
Thanks
Tiankun

_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio