[Ronja] Multiple receivers and transmitters

[PRAMOD YADUVANSHI]

I feel for a laser based link MIMO will be a better option to improve SNR
but for LED based Tx/Rx scintillation effects will be almost negligible and
MIMO will hardly help.

2008/9/20 Gregory Maxwell <gmaxwell at gmail.com>

> On Sat, Sep 20, 2008 at 1:09 PM, J.D. Bakker <jdb at lartmaker.nl> wrote:
> >>I have been thinking how to divide multiple heads between receivers
> >>and transmitters optimally, i. e. if we want to build N heads, how
> >>to get the maximum range.
> >
> > Given N transmitters and M receivers, it might be better (but more
> > complicated) to apply MIMO techniques.
>
>
> In radio the problem that MMIO solves is multipath: Between your TX
> and RX  there are obstructions which alter the signal, they shift
> phase in a frequency dependent manner, and creates nulls and peaks.
> MMIO uses spatially separated antenna which get different views of the
> multi-path environment.  You can then define a collection of filters
> which take advantage of the multipath to form separate channels and
> gain capacity.
>
> For a fairly slowly amplitude modulated optical path like RONJA I
> would not expect there to be significant multipath. I do not believe
> MMIO would help.  But MMIO systems typically use efficient modulation
> systems  which would probably help ronja very much, but supporting
> them would be very costly.
>
> Karel where does the noise come from in the receive head are we
> talking about optical background noise which would increase with
> increased collection area or is it primarily noise from the
> photodetector and amplifier?   If it is primary electronic noise,
> creating a larger passive collector may allow you to increase receiver
> area without seeing much of a nosie increase.
>
> So long as your transmitter area is strictly smaller than the
> reciever's field of view, however, you would always be as well or
> better off to increase the transmitter area.  though perhaps you may
> wish to make the receiver more selective (for example, by placing it
> at the back of a long black tube).
>
> --
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>
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