Analog Devices ADRV9002 User Manual

Preliminary Technical Data UG-1828
Rev. PrC | Page 209 of 338
It is used to detect a valid data capture for DPD/CLGC operation if a specified number of samples (countsGreaterThanPeakThreshold)
are greater than the defined peak threshold. (DPD/CLGC operation needs a good set of large signal samples to model the PA compression
behavior properly.)
countsLessThanPowerThreshold
It defines the number of samples below the detectionPowerThreshold to determine an invalid capture. To disable it, user can set it to be
the DPD/CLGC maximum number of capture samples 4096.
countsGreaterThanPeakThreshold
It defines the number of samples greater than the detectionPeakThreshold to determine an valid capture. To disable it, user can set it to be
0.
immediateLutSwitching
When a new DPD solution is formed, the new solution is loaded into a spare LUT, which can then be switched with the active LUT. There
are two options regarding the LUT switching. When immediateLutSwitching is set to be “TRUE”, the new LUT swaps out the active LUT
immediately when ready. When immediateLutSwitching is set to be “FALSE”, after the updated LUT is available, LUT swapping is
triggered after the next data frame is completed. Note this only applies to TDD operations. FDD systems should always use immediate
LUT switching. Currently, it should always set to be “TRUE”.
useSpecialFrame
In order to achieve optimal performance, DPD must capture the peaks of the signal. Some standards allow for transmission of special data
that can be used for DPD estimation. In other cases, the baseband processor may know in advance that a frame will contain good data for
DPD estimation. In these cases, the user may choose to control which frames are used for DPD. The flag indicates that the user will
control the frames that DPD can capture. This is currently not supported so it should be disabled.
resetLuts
To start DPD operation from a known state, user should reset LUTs. By setting resetLuts to be 1, it sets most polynomial terms to be 0 to
remove the pre-distortion at the beginning of DPD operation.
timeFilterCoefficient
This parameter defines the coefficient of a single pole filter which can help to mitigate the spectral spikes caused by LUT switching,
especially in FDD and NB use cases. In TDD, user could avoid spectral spikes by not performing immediate LUT switch. The range of
“timeFilterCoefficient” is between 0 and 1. If setting it to be 0, it is equivalent to disable this functionality. User can experiment this
parameter and pick the optimal value to reduce the spikes. User should also note that enabling this feature might hurt the convergence
time. The bigger this parameter is, the slower the convergence might be. Therefore, this method should be considered as an available tool
when all other methods are exhausted and be employed with caution.
dpdSamplingRate_Hz
This parameter is for showing the sampling rate in Hz for the DPD actuator and capture. It is read only and does not have any effect on
DPD configurations.
clgcLoopOpen
This parameter is used to open or close the gain control loop. When it is set to 1, the transmit attenuators are not updated. This is used to
measure the gain to help determine the target gain. Once target gain is set, user should set it to 0 to close the loop to start CLGC
operation.
clgcGainTarget_HundredthdB
This parameter should be configured by user to notify ADRV9001 about the gain target for CLGC in an accuracy of hundredth of a dB.
clgcFilterAlpha
This parameter stands for the coefficient of a single pole filter to smooth the gain measurement. The min value is 0 which is equivalent to
disable this filter by using the instantaneous gain measurement result. The max value is 1 and the default value is 0.75. User could set
bigger value to achieve smoother gain measurement results.
clgcLastGain_HundredthdB
This parameters represents the unfiltered gain measurement results when loop is open. User could use API to retrieve this value which is
in a accuracy of hundredth of a dB. Note this parameter is only valid for retrieving.
clgcFilteredGain_HundredthdB

Analog Devices ADRV9002 Specifications

General

Brand	Analog Devices
Model	ADRV9002
Category	Transceiver
Language	English