CCA Preamble Detect – Fact vs. Fiction – Full email thread initiated by C. Lukaszewski – 9/27/2015

[Rick Murphy]

On Dec 1, 2015, at 6:31 AM, Rick Murphy wrote:

Chuck,

Thanks for digging this up. If it’s in Eldad’s book then I know its solid. I know this should be obvious, but I’ve always had difficulty reading these waterfall charts. Can you help with the following?

If
10^-2 = .01 = 1%
then it follows that:
10^-1 = .1 = 10%
and
10^0 = 1.0 = 100%.

Why does the * on the 4 dB scale = 15%?

Thanks,
Rick

[Rick Murphy]

On Dec 1, 2015, at 9:46 AM, Chuck Lukaszewski wrote:
Note the log scale on the Y axis.

The * at 4dB corresponds to 10^-0.8.

10^-0.8 = .1585 = 15.8%

The x^y button on windows calculator will produce this for you. Be sure to change the sign on the .8 before hitting equals.

-cl

[Rick Murphy]

On Dec 1, 2015, at 12:26:10 PM, Rick Murphy wrote:

Got it!

On the Windows7 calculator in Scientific view:
press: 10
press: x^y
enter: .8
press: -^+ (plus over minus key to change sign)
press: =
result: 0.158489319244611134852021013733915 (Because, I thrive on precision :-))

Thanks so much.
Rick

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