Agilent Technologies J-BERT N4903, User Manual

Page: 203 / 434

This graph shows the absolute values of the derivative of the bit error
rates over the thresholds (dBER/dThreshold). It visualizes the data that
forms the basis for the calculations of the level and noise values.
The graph provides a special marker that allows you to estimate the data
distribution by approximating it by means of a Gaussian normal
distribution.
The Output Levels measurement provides a third graphical display: the
Q from BER versus Threshold graph. This graph refers to the Q-factor
calculations. For details on these calculations see “QBER vs. Threshold
Graph” on page 208 and “Understanding the Q-Factor Results” on page
216 .
Output Levels - Reference
The Output Levels measurement returns the results in a graphical and
in a numerical form. The following sections provide explanations of the
measured parameters and the display options that are specific to this
measurement. Additionally, some information is provided to explain
the theoretical background behind.
The properties of the Output Levels measurement can be specified on
the various tabs of the
Properties dialog box.
Parameters Tab
N O T E
If you modify the parameters on this page, you have to rerun the measurement to
update the results.
Set the criteria for moving to the next sample point:
•
Number of Compared Bits
After this number of compared bits, the measurement stops for the
current sample point and moves to the next one.
Advanced Analysis
5
Agilent J-BERT N4903 High-Performance Serial BERT 203