Analog Devices ADRV9005 Reference Manual page 243

Reference Manual ADRV9001
DIGITAL PREDISTORTION (DPD)
clgcFilterAlpha
This parameter stands for the coefficient of a single-pole filter to smooth the gain measurement. The minimum value is 0, which is equivalent
to disable this filter by using the instantaneous gain measurement result. The maximum value is 1, and the default value is 0.75. Set the bigger
value to achieve smoother gain measurement results.
clgcLastGain_HundredthdB
This parameter represents the unfiltered gain measurement results when the loop is open. Use API to retrieve this value, which is in an
accuracy of a hundredth of a dB. Note: This parameter is only valid for retrieving.
clgcFilteredGain_HundredthdB
This parameter represents the filtered gain measurement results when the loop opens (based on the user-configured filter coefficient). Use API
to retrieve this value, which is in an accuracy of a hundredth of a dB. Note: This parameter is only valid for retrieving.
captureDelay_us
This parameter delays the DPD capture from the beginning of the transmitter frame by an amount of time (in μs) specified. By default, it is set
to 0. However, It can help avoid using transmitter data at the beginning of a transmitter frame, such as preamble or control signal, which has a
characteristic not suitable for DPD operation. Note: This parameter applies to both DPD and CLGC.
Configure the DPD/CLGC post initial calibration parameters through TES, as shown in Figure 221. Note: All data capture related configurations
such as "Number of Samples," "Capture Delay (us)," "Rx/Tx Normalization", and "Activation" are also used by the CLGC algorithm.
Figure 221. Configuring DPD/CLGC Post Initial Calibration Parameters Through TES
DPD/CLGC Updates Scheduling
As described in the Tracking Calibrations Scheduling section, tracking calibrations will run periodically in FDD profiles and at the start of a frame
in TDD profiles. DPD will be scheduled to run approximately every 200 ms for the first four iterations and every 2 sec thereafter.
Optionally, user can allow DPD/CLGC tracking calibrations to run periodically during a TDD frame. This can be used in long frame times where
DPD/CLGC may need to update during a frame time. In TES, this can be selected via the 'Repeated Estimation TDD' in a frequency hopping
profile.
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