Dpd Stability Metrics Characterization - Analog Devices ADRV9029 User Manual

Step Action
17 Monitor CLGC tracking calibration status

DPD STABILITY METRICS CHARACTERIZATION

The following stability metrics are at the disposal of the user for defining stability:
Transmit power thresholds
Observed power thresholds
•
Direct EVM - Difference between measured pre DPD transmitted and observed samples
•
Indirect EVM – Difference between measured post DPD transmitted and observed samples
•
Indirect Error – Difference between measured post DPD transmitted and predicted samples. Predicted samples are obtained
•
by applying the DPD model to the observed samples
•
Select Error – Same as indirect error, but, computed for post DPD transmitted samples whose amplitude is greater than –30
dBFS
•
All the above metrics are user configurable. The following section provides characterization data which might provide some
guidance regarding factors that could influence the configuration of the stability metrics defined.
Shown below are three cases where the stability metrics direct EVM and indirect Error parameters are compared for different
Measuring DPD Adaptation Performance through Direct EVM and Indirect Error
ACLR performance levels of an NR100 signal TM3.1 signal.
Case 1: The ACLR performance is ~46.6 dBc in L3 channel and corresponds to a direct EVM of 2%.
Case 2: The ACLR performance is better (~47.5 dBc) than case 1, which also corresponds to reduced direct EVM.
Case 3: The ACLR performance is best amongst the three cases (~48.5 dBc) which is reflected in the reduced direct EVM
numbers.
Figure 35. Bad ACLR Performance Correlation with a High Direct EVM Value
Figure 36. Improved ACLR Performance Corresponds to Improved Direct EVM
Rev. PrA | Page 34 of 82
Preliminary Technical
APIs used
adi_adrv9025_ClgcStatusGet
Data