Re: [Openbts-discuss] Radio boards: 2 x RFX900 vs RFX900 + DBSRX

[Joshua L. <jl...@th...>]

Sorry to take so long to reply.  I'm buried in projects!


Quoting Sylvain Munaut (24...@gm...):
[...]
> > I have a modified version of the USRPDevice class that allows
> > "arbitrary" daughterboard support.  (Arbitrary in quotes because really
[...]
> 
> 
> Could you send me a copy of this ? Or a link.
> 
> I've just ordered a my USRP and cards, I'll give it another shot :)

I will.  However I just tried it out with a hardware setup I know works
and I couldn't get consistent results.  It's on my list of things-to-do
and I'll make sure you get a copy when it actually works.


> > However, it turns out that OpenBTS really needs MIMO_B to work.
> > Otherwise your transmit and receive wander around a bit too much for
> > most phones to connect correctly.  Now MIMO_A may work, and that is the
> > best you can do with a DBSRX anyway, but I couldn't get it to work
> > during my limited testing.  By the time I had this figured out I had two
> > RFX900/1800 cards anyway and started looking at something else...
> 
> 
> So you tried with MIMO_A and couldn't
> Did you switch the RFX to MIMO_A too or did you use A for one and B for the
> other ?

IIRC, I told the RFX it was also MIMO_A.  (Which is simply done by
writing a different daughterboard ID to the card, I think...)  The
problem is that I was modding all sorts of stuff at the time and I
really don't remember the details of that particular experiment.

What I'll do is get my class to work with the standard two RFX MIMO_B
cards and then leave the rest up to you.  :)

Give me a couple of weeks.