Adrv9001 Dpd Supported Waveforms - Analog Devices ADRV9005 Reference Manual

Reference Manual
DIGITAL PREDISTORTION (DPD)
In the ADRV9001 device, DPD is considered one of the transmitter tracking calibrations. It is a real-time signal processing with iterative updates
to account for hardware variations such as temperature and power level changes. Similar to other transmitter tracking calibrations, it requires
a loopback path from the transmitter to the observation receiver (ORx) to perform the calibration. In this case, an external loopback path
(ELB) type 2 is required (see the
the transmitter output signal after PA is looped back to the ORx, as shown in
integrated DPD. In FDD applications, where only one receiver is used or in the TDD applications during transmit time slots, unused receiver
path can be used for DPD calibration and other transmitter tracking calibrations. See the
details.
Similar to what is shown in Figure
"Coefficients Calculation Engine" computes the DPD coefficients periodically and then updates the "DPD Actuator" for real-time predistortion
of the transmit signal. The predistortion coefficients are associated with polynomial terms defined by the PA model. To meet the real-time
processing requirement, polynomial terms associated with a common time-delay input data are precomputed and stored into look-up tables
(LUT) in the "DPD Actuator." In the device, without frequency hopping, two LUTs are used for all waveforms. One is active to perform
predistortion, while the other is updated in the background to track the changes and replace the current LUT when ready, resulting in complete
transmit operation. The "DPD Actuator" also includes the functionality to calculate the amplitude of the input signal, which is used to search the
LUT. The outputs of the LUT are then multiplied with different time-delayed input data according to the configured DPD model and combined to
form the final predistorted transmit data.

ADRV9001 DPD SUPPORTED WAVEFORMS

The integrated DPD supports narrowband waveforms such as TETRA. Note: some narrowband standard waveforms, such as direct modulation
types with constant envelope, do not require DPD. See
TETRA 1 and 2 modes.
Table 94. Supported Narrowband Standards and Associated Operational Parameters
Standard Bandwidth (kHz)
TETRA1 25
TETRA2 25
TETRA2 25
TETRA2 25
TETRA2 50
TETRA2 50
TETRA2 50
TETRA2 100
TETRA2 150
Besides that, the integrated DPD supports some wideband long-term evolution (LTE) and LTE-like waveforms with their associated operational
parameters. Other wideband waveforms can be supported if the PA behavior fits the designed hardwired amplifier model, as well as the
sampling rates and transceiver bandwidth.
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Receiver/Observation Receiver Signal Chain
Figure 211. High Level Block Diagram of ADRV9001 DPD Implementation
211, DPD includes two major components; a "DPD Actuator" and a "Coefficients Calculation Engine." The
Table 94
Modulation
DQPSK
4 QAM
16 QAM
64 QAM
4 QAM
16 QAM
64 QAM
64 QAM
64 QAM
section for more details about the loopback paths), in which
Figure 211. Ensure to establish this path before enabling the
ADRV9001 Example Use Cases
for TETRA's different modes of operations. The integrated DPD supports all
Number of Carriers
1
8
8
8
16
16
16
32
48
ADRV9001
section for more
PAR (dB) Before CFR
3.1
9.6
9.5
10.3
10.2
10.3
10
11.2
10.8
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