Why “Diversity” Isn't Enough
by Ira S. Faberman,
Iftron Technologies, Inc.
It all seems simple enough: get two tuners and two antennas spaced apart.
Then when one antenna is compromised by signal fade and signal bounce, the other
antenna may have a better signal to offer.
So all we need to do now is select the best signal and send it to the output, right?
But that's when all the trouble starts. It turns out that selecting the best signal, which seems easy
at first glance , is no easy task. Take diversity systems that work on received signal strength
(RSSI for short)as an example. It seems clever to monitor the signal strength of each signal
and pick the strongest one, because the strongest signal must be the best signal, right?
Well as it turns out, the answer is 'only sometimes.' Consider an antenna that is being blasted by
a signal from some interfering source. The interfering signal may appear stronger, but it's not your
signal. Instead of being yours, it could be anything—wifi, some other form of communication or
who knows what? But whatever it is, if you send it to your video screen, you can bet that the
result is going to be pretty ugly. Suddenly it's not so clear (pun intended) that RSSI
diversity systems are a good solution.
Or how about those systems that are made from two single receivers and a switching box that
examines the video sync pulses to see if one is missing? It seems reasonable that if they could
detect when one was missing, they could switch to the other signal, right? You already know the
answer: 'only sometimes.' That's because by the time they figure out that the sync pulse is missing,
the video signal and therefore the way it looks on your screen is already loused up.
Worse, if you switch to the other signal, it may have a missing sync pulse too.
Then what? You see, it's not uncommon for your video transmission to mix it up with interfering
signals to produce some really weird results that still include your original sync pulses.
The resulting signal still looks O.K. to some diversity systems and no diversity switching occurs.
This type of diversity system just can't cope with this sort of thing and is not going to make
you very happy.
So at Iftron, we decided to rethink the problems and limitations of diversity receivers and the result
is a patent pending line of diversity products that combine real-time analysis of signal quality and
sync pulse integrity in a novel way to determine which signal is the best. The result is a diversity
system that we think is better then the sum of its parts. By uniquely combining the most
important factors, our system chooses the best signal more often then either of the afore
mentioned methods combined. Yes, there will be those times when neither signal is a good
choice, so we can't claim to walk on radio waves, but on average, our novel system turns in
performance that can outshine systems costing thousands more. Best of all, we have
built this patent pending performance into both our YellowJacket Pro and our new Nano Modular
Diversity products. So whichever you choose, Iftron has you covered.
Iftron. “Stuff That Works” tm
IFtron (US) cable pinout:
Tip = white audio
First ring from the tip = yellow video
Second ring = ground
Third ring = red audio
IMMERSIONRC versus IFTRON amazing comparison !!
want to see more proof why Clearview is the best?!