Re: [Discuss-gnuradio] Re: USRP2 802.11 BBN code on the TX side

[Doug Geiger]

George Nychis wrote:
> Hi Doug,
>
> I can guarantee you that the scrambler is not working ;)  The 802.11 
> spec states that at the beginning of every transmission, the scrambler 
> needs to reset its seed, however the BBN code does not do this.
>
> That's interesting on the clocks.  What daughterboard are you using?
>
> - George
I'm using the RFX2400. Looking at the spectrum in a spectrum analyzer 
suggests we aren't making the correct spectrum on transmit - not sure if 
that's simply because we aren't doing any filtering (i.e. RRC or other 
pulse shaping), or if it's something more fundamental.
I think as long as the scrambler isn't set to all ones at the start of 
a transmitted frame, we're all good. It's self-synchronizing, so it 
doesn't need to be at any known state at the start of a frame.

--
Douglas Geiger
Code 5545
U.S. Naval Research Laboratory
Washington, DC 20375
(202) 767-9048
address@hidden