Dpd With Frequency Hopping (Fh); Adrv9001 Dpd Performance - Analog Devices ADRV9001 User Manual

Reference Manual
DIGITAL PREDISTORTION (DPD)
Table 90 shows the supported wideband LTE standards and their associated operation parameters.
Table 90. Supported Wideband Standards and Associated Operational Parameters
LTE Bandwidth (MHz)
1.4
3
5
10
15
20
Note: The ADRV9001 DPD can also be enabled for the LTE 40MHz profile with a slightly degraded performance, due to the limited DPD
observation bandwidth.
Table 89 and Table 90 show that the multicarrier TETRA2 has a PAR between 9.6 dB to 11.2 dB, and the multicarrier LTE signal typically has
a PAR of about 11dB. Therefore, to achieve higher PA efficiency and DPD algorithm stability, a waveform with a large PAR is expected to
perform crest factor reduction (CFR) in baseband processors before DPD operation. Ensure that CFR is applied to a multicarrier signal before
transmission as it keeps the average power higher while maintaining the same peak back off in the digital transmit data. Also, CFR suppresses
large peaks to below a preset threshold, thereby eliminating occasional large peaks that can make DPD unstable if the peak is beyond the
compression threshold limit of the power amplifier. For example, an LTE signal has a PAR of about 11 dB and the PAR can be reduced by
CFR to about 7 dB by trading off the EVM. Note that the the baseband processor is responsible to perform CFR with an appropriate trade-off
between the PAR reduction and EVM degradation before sending the transmit data to the ADRV9001. Note: The additional EVM degradation
caused by the integrated DPD is negligible compared to the degradation caused by the CFR.

DPD WITH FREQUENCY HOPPING (FH)

The ADRV9001 also supports DPD operation during frequency hopping (FH). In this case, there is an option to identify multiple frequency
regions, and for any LO frequency in one region, the same DPD solution is applied. The ADRV9001 allows a maximum of eight frequency
regions. Define each region by specifying the lower bound and upper bound LO frequencies ([lower bound, upper bound)) for up to seven
regions. The rest LO frequencies are in the eighth region. Refer to the

ADRV9001 DPD PERFORMANCE

The integrated DPD algorithm has been tested using both metal–oxide–semiconductor (MOS) type and gallium nitride (GaN) type of PA. For
example, Figure 188 and Figure 189
before and after DPD without FH. The test waveform is TETRA1.
corrects the PA's nonlinearity.
analog.com
Number of Carriers
Multicarrier
Multicarrier
Multicarrier
Multicarrier
Multicarrier
Multicarrier
show the AM-AM and AM-PM performance of the raw transmit signal input vs. the MOS type of PA output
Figure 189
Figure 188. Raw Transmit Signal Input vs. Nonlinearized Power Amplifier Output
PAR (dB) Before CFR
~11
~11
~11
~11
~11
~11
Frequency Hopping chapter for more details.
clearly shows that the integrated digital predistortion successfully
ADRV9001
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