Keysight M8000 Series of BER Test Solutions User Guide 483
Working with Measurements 8
Explanation of the Fast Total Jitter Measurement
The Fast Total Jitter measurement is an optimized method to determine
the total jitter for devices that generate a very low error density (BER well
below 10
-10
).
To measure (not estimate) the total jitter for a device with a BER of 10
-12
with conventional methods, one usually needs to compare more than 10
12
bits for each sample point. To measure a full eye opening this way with
appropriate timely resolution takes time (maybe days or weeks, depending
on the data rate), and the probability of seeing one or no error in 10
12
bits
is not higher than 37%.
If one would compare 10
13
bits for the same device, the probability of
seeing ten errors is even lower (12%), but the probability of observing no
error is almost zero.
The Fast Total Jitter measurement implements a method that reduces the
measurement time considerably and provides a higher accuracy. It is
based on statistical and probability calculations.
10
10
10
10
10
10
10
0
-2
-6
-4
-8
-10
-14
-12
-16
10
10
BER Threshold
Min. BER for RJ/DJ
Separation
Residual BER for
Estimated TJ
0-0.2 0.4 0.6-0.8 0.2 0.8-0.4-0.6
Extrapolated Bathtub (log scale)
BER [-]
Delay Adjust [ui]
To Next Page
Loading...
Need help?
General
