Re: [Discuss-gnuradio] GRC 3.6 / 802.11 a/g test signal

[Bastian Bloessl]

On 10/09/2014 10:40 AM, Ernest Szczepaniak wrote:
> Greetings,
>
> finnaly got it working :D Problem was with descrambler. Now it gives results
> as follows:
>
>                              Service: 'ok'
>                            Duration: '0000'
>           Source_MAC_Adress: '232323232323'
>     Destination_MAC_Adress: 'FFFFFFFFFFFF'
>                 Protocol_version: 'Supported'
>                                  Type: 'Data'
>                             Subtype: 'Data'
>                                To_DS: 'False'
>                            From_DS: 'False'
>                  More_fragments: 'No'
>            Power_menagement: 'Active'
>                          More_data: 'No'
>                           Protected: 'No'
>                                 Order: 'Random'

Great

> But I still dunno how to estimate initial descrambler state (checked all and
> found correct one this time).
> Descrambler graph sould be the same as the scrambler from you paper right?
On the receiving side, take the first 7 bits, put them in the scrambler 
register, and use the very same algorithm on as on TX side. (Since the 
output of the scrambler is fed back the first seven bits are also the 
internal state of the scrambler).

Bastian