MULTILANE ML 4015D, Руководство пользователя

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26
SNDR
Signal-to-Noise Distortion Ratio in dB.
SNDR is defined by:
10 × log
10
(
𝑃
𝑚𝑎𝑥2
𝜎
𝑒2
+ 𝜎
𝑛2
) where
P
max
is the
maximum value of P(k) which is the linear fit
pulse response,
𝜎
𝑒
is the standard deviation
of the error e(k) and
𝜎
𝑛
is the RMS deviation
from the mean voltage at a fixed point in a
run of at least 8 consecutive identical levels.
AOP
Average optical power of the input signal in
dBm.
Calculated average optical power is the
average power level of all captured points in
the eye diagram.
Measured average optical power is derived
from the optical-to-electrical converter
within the scope.
Outer OMA
The outer OMA (Optical Modulation
Amplitude) depicts the difference between
the power levels of the highest logic level (11
in PAM4) and the lowest logic level (00 in
PAM4) in dBm. It is measured from
consecutive identical bits of the two levels.
TDECQ
Transmitter and Dispersion Eye Closure for
Quaternary.
TDECQ is, as defined by the IEEE, a measure
of each optical transmitter's vertical eye
closure when transmitted through a worst-
case optical channel, as measured through
an optical to electrical converter (O/E) and
equalized with the reference equalizer.
OMA
The standard OMA (Optical Modulation
Amplitude) depicts the difference between
the power levels of the ‘1’ and the ‘0’ logic
level of an NRZ signal in dBm.