[App_rpt] Voters

[Bryan Fields]

On Saturday 21 January 2006 09:57 pm, Steve Rodgers wrote:
> I'm not aware of any feature like this in GSM. With regard to DSP required,
> it would probably involve measuring the noise content of a signal. The
> problem is, that there's no easy way to determine noise from a valid signal
> when measuring energy and spectrum in band. What this means is you would
> probably have to get your signal quality from noise outside of the
> bandwidth of the channel similar to what happens with noise squelch
> circuits.

Well S/N voters work with just the audio from a link rx and cor.  They do this 
using op amps that only amp the high frequency componits of a signal.  This 
can be done with two op-amps fed into a comparator.  There must be some way 
to code an op amp function in a DSP/CPU and have it out put a value for a 
signal with more highfrequency content in it.

> Also, there is something else I forgot to mention in the issue list under
> Internet weather. There needs to be a way to adjust the delays dynamically
> between all of the receive channels so that when  the voter switches audio
> channels, there is no repeated or dropped voice frames. This may not be a
> trivial exercise.

Well if you own the network and your running IPoATM or IP+QOS it's easy to 
route the traffic with low jitter.

-- 
Bryan Fields
Chief RF Engineer/Partner
illiana.net
219-306-1805