Analog Devices ADRV9029 User Manual page 18

DPD Mode of
Operation
ADI_ADRV9025_DPD_M
ODE1
ADI_ADRV9025_DPD_M
ODE2
Description
DPD coefficients corresponding to the GMP model are updated only if the RMS power measured
by the DPD exceeds the previously recorded maximum RMS power by the DPD algorithm. The
RMS power is calculated on the samples captured by the DPD for coefficient computation. The
number of samples to capture for a DPD update is specified by
adi_adrv9025_DpdTrackingConfig_t.dpdSamples. Typically this is set to 16384 samples. The
recorded maximum power decays at a fixed rate of 0.2 dB per update.
Shown in Figure 21 is an illustration of DPD updates in Mode 1. The DPD algorithm updates
coefficients only when the RMS power measured by the DPD during the update exceeds the
previously recorded maximum power. In this example, there is no update b/w Update 1 and
Update 2 because the RMS power is below the max power recorded.
DPD Mode 1 offers the best mitigation of transient emissions when the signal changes rapidly, at
the expense of sustained performance in certain low-power signal conditions.
In this mode, the DPD algorithm maintains 2 separate look up tables, one for low power region
and the other for the high power region. Depending on the RMS power measured by the DPD
on the samples captured for coefficient computation, the DPD algorithm either switches to the
high power look up table(M-Table) or the low power look up table(C-Table), and the same look
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Figure 20. DPD Mode 0 Update Example
Figure 21. DPD Mode 1 Update Example
Preliminary Technical
Data