700 Mhz Spectrum Auction

kenneth marken k-marken at online.no
Sun Aug 5 23:31:40 CEST 2007

On Sunday 05 August 2007 20:21:57 Derek Pressnall wrote:
> On 8/2/07, Ian Stirling <OpenMoko at mauve.plus.com> wrote:
> > Wolfgang S. Rupprecht wrote:
> >
> > However, the signals from distant stations still interfere, and increase
> > the channel noise level, reducing range.
> > With planned networks, this is all managed.
> > With unplanned networks, it could in principle auto-configure, but only
> > if everyone implements the same fairness protocol.
> I had an idea that may help reduce radio interference in point to
> point communications.  Lets say if one end (the base) was set up to
> broadcast using multiple antennas aranged in some sort of pattern,
> with a minimum of 3 antennas.  If they were each sending out the same
> signal, then each tower's signal will reach a particular handset at a
> different time (since the towers are spaced apart).  Which means that
> each "stream" will have different noise/interference patterns, and the
> handset can then process each signal seperately, re-align them in
> software and pull out the similaraties and differences in each radio
> stream.  This way the handset can  "focus" on the signal comming from
> a particular group of towers and be able to eliminate most of the
> noise.
> The reverse can be done and the base end -- to pick out a signal
> coming from a particular handset, just adjust how it overlaps the
> signal streams comming from each tower, and it can focus on a single
> handset.
> Not sure how much processing power this would take, or how far apart
> the antennas would need to be at the base, but it seams like it would
> be an effective way to multiply the number of point-to-point links
> that can be established within a given amount of radio spectrum.

sounds like a cross between mimo and direction finding to me.

would be interesting to try it :)

More information about the community mailing list