Keysight N4917CPCA Optical Receiver Stress Test for CPRI Fronthaul Networks User Guide
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Concepts and Features of N4917CPCA Software
3
To speed up the stressed eye calibration, you may set the starting values
for data amplitude, ISI amplitude, SI amplitude, PJ2/BUJ, and RJ/BUJ.
Once the software achieves the initial stressed eye waveform from the
setting parameters, the system adjusts those parameters until the
measurement parameter targets are achieved. The measurement
parameters—ER, VECP, J2 and J9—are adjusted using the parameters—
data amplitude, ISI amplitude, SI amplitude, PJ2 or BUJ amplitude, RJ or
BUJ amplitude. Initial VECP is the portion created from ISI (inter-symbol
interference). Initial VECP should be at least 2/3 of the VECP target.
The full value of VECP is then achieved by adding additional SI (sinusoidal
interference) and jitter.
Jitter Conformance Test
This feature of the N4917CPCA software performs a jitter tolerance test
based on the applicable standards, to confirm that the DUT meets the
required Bit Error Rate (BER) when the specified SJ amplitude is applied at
each SJ frequency. Note that the Jitter Conformance Test sets up only the
SJ stress level. You must manually enter the device BER and the Pass/Fail
criteria. The test builds a table and a plot for SJ frequency/amplitude
versus BER.
As a prerequisite, you must run the Stressed Eye Calibration prior to
running the Jitter Conformance Test.
lists the Setting and Measurement Parameters for Jitter
Conformance Test:
Measurement Parameters
[ER] Extinction Ratio (dB)
Initial [VECP] Vertical Eye Closure Penalty (dB)
[VECP] Vertical Eye Closure Penalty (dB)
J2 jitter (UI
pp
)
J9 jitter (UI
pp
)
[DDPWS] Data Dependent Pulse Width Shrinkage (ps)
Calibration level OMA (dBm)
Parameters
