Re: Question about OFDM channel estimation block

[Marcus Müller]

Hi Philip,

You probably found the pilot_carrier variable (red ellipse in Fig1.svg). That's used in 
both the `header_equalizer` and `payload_equalizer` variables. These are used in the two 
`OFDM Frame Equalizer` blocks for the Header Stream and the Payload Stream.

An easy way to find things that depend on a variable is just selecting the variable block, 
and disabling it (pressing the "d" key), and see what turns red.

Best regards,
Marcus

On 09.05.23 16:54, Philip Cao wrote:
> Hi Marcus
>
> The block I checked is the flow graphs you mentioned. And I didn’t find something related 
> pilot in the channel estimation block
> Thank you so much
>
> Best regards
> Philip
> ------------------------------------------------------------------------------------------
> *发件人:* discuss-gnuradio-bounces+caoyanmingde=gmail.com@gnu.org 
> <discuss-gnuradio-bounces+caoyanmingde=gmail.com@gnu.org> 代表 Marcus Müller <mueller@kit.edu>
> *发送时间:* 星期二, 五月 9, 2023 23:27
> *收件人:* discuss-gnuradio@gnu.org <discuss-gnuradio@gnu.org>
> *主题:* Re: Question about OFDM channel estimation block
> Hi Philip,
>
> have you checked the OFDM example flow graphs that come with GNU Radio? They're 
> usually
> installed in a place like /usr/share/gnuradio/examples/digital/ofdm.
>
> Best regards,
> Marcus
>
> On 08.05.23 08:56, Philip Cao wrote:
>  > Hi everyone!
>  >
>  > I am trying to learn something about the OFDM system and I found that in the 
> code of OFDM
>  > channel estimation block, it uses the synch. word and without pilot symbols. 
> I think it
>  > should also have some function related to the pilot but there is not. Could 
> someone help
>  > me about this?  This means that if you want to implement channel estimation 
> using pilot
>  > with GNU radio you need to use a custom module, is this correct? Any help 
> would be greatly
>  > appreciated, thanks!
>  >
>  > Best regards
>  > Philip

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