David,
Speaking of the PAPR issues, I came across Walsh Hadamard Transform which
some research claims can get as much as 5 to 10db and the ability to use a
Class C PA.
Do you think something like that could help?
Daniel Mundall
On Tue, Mar 5, 2013 at 8:42 PM, David Rowe <[email protected]> wrote:
> Hi Daniel,
>
> Yes I have wondered if a separate rx with separate antenna might help
> get around fades. I imagine there needs to be a certain separation
> (certain number of wavelengths) between the antennas.
>
> Some other ways to get that 6dB are coding gain (if FEC can be made to
> work better) and lower Codec bit rates (if that doesn't make the
> robustness worse). At the tx end higher average power (reducing PAPR
> issues) would also help the link budget.
>
> Thanks,
>
> David
>
> On Tue, 2013-03-05 at 20:30 -0800, Daniel Mundall wrote:
> > David,
> > Amazing to see all the work that has gone into getting it where it is.
> > Thinking about that 6db you are looking for, wouldn't it be possible
> > to get that at some point with something like SoftRock with dual tx-rx
> > chains (MIMO)? It may not be practical for the lower bands(antenna
> > size), but when possible it may be one of the easiest ways to get that
> > link budget and possibly even lower the tx power.
> > I found some of the ideas here interesting
> > http://www.sequans.com/pdf/SequansUplinkMIMOWP0608_v2.pdf
> > It may not something for right now, but it looks like something with
> > potential for the future.
> > 73s
> > Daniel
> >
> >
> > Sent from Daniel's iPhone
> >
> > On Mar 5, 2013, at 12:09 PM, David Rowe <[email protected]> wrote:
> >
> >
> > > Hello,
> > >
> > > I have just published a new blog post on making FreeDV robust over
> > > HF
> > > multipath channels:
> > >
> > > http://www.rowetel.com/blog/?p=2905
> > >
> > > Thanks,
> > >
> > > David
> > >
> > >
> > >
> > >
> ------------------------------------------------------------------------------
> > > Everyone hates slow websites. So do we.
> > > Make your web apps faster with AppDynamics
> > > Download AppDynamics Lite for free today:
> > > http://p.sf.net/sfu/appdyn_d2d_feb
> > > _______________________________________________
> > > Freetel-codec2 mailing list
> > > [email protected]
> > > https://lists.sourceforge.net/lists/listinfo/freetel-codec2
> > >
> >
> ------------------------------------------------------------------------------
> > Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester
> > Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the
> > endpoint security space. For insight on selecting the right partner to
> > tackle endpoint security challenges, access the full report.
> > http://p.sf.net/sfu/symantec-dev2dev
> > _______________________________________________ Freetel-codec2 mailing
> list [email protected]
> https://lists.sourceforge.net/lists/listinfo/freetel-codec2
>
>
>
>
> ------------------------------------------------------------------------------
> Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester
> Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the
> endpoint security space. For insight on selecting the right partner to
> tackle endpoint security challenges, access the full report.
> http://p.sf.net/sfu/symantec-dev2dev
> _______________________________________________
> Freetel-codec2 mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/freetel-codec2
>
------------------------------------------------------------------------------
Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester
Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the
endpoint security space. For insight on selecting the right partner to
tackle endpoint security challenges, access the full report.
http://p.sf.net/sfu/symantec-dev2dev
_______________________________________________
Freetel-codec2 mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/freetel-codec2
