On Jun 3, 2010, at 4:49 PM, Nate Duehr wrote:
On 6/2/2010 5:39 AM, Woodrick, Ed wrote:
You’ve been a part of this same D-STAR Signal Coverage conversation
many times and the answer is always the same, time after time. And
you don’t seem to see where even classic BER calculations have
significant issues defining the quality of the signal that is
received. The FEC plays havoc with classical signal measurements.
Actually Ed, I have always said the BER dropout point is a TEST
point. A known place where you can compare system-to-system. You
can't make better what you can't measure.
Been doing this kind of measurement (with and without FEC) for
decades in land-line digital telco... it works just fine
If a company says, "at X% BER our chip gives up" then you have a
known test point. FEC doesn't matter... because the FEC is included
and part of that specification. The chip can have the best FEC in
the world, it still drops out at the same point, time after time,
consistently -- giving the perfect test point.
Nate WY0X
__._,_.__
The company claims 20% BER to loss of usable signal on AMBE chips.
_
John D. Hays
Amateur Radio Station K7VE
PO Box 1223
Edmonds, WA 98020-1223 VOIP/SIP: [email protected]
Phone: 206-801-0820
801-790-0950
Email: [email protected]
