UG-1828 Preliminary Technical Data
Rev. PrC | Page 208 of 338
Parameter Type Description Min Max Default Note
could hurt
convergence. A
coefficient of
zero means no
filtering.
dpdSamplingRate_Hz uint32_t Sampling rate in Hz for the
DPD actuator and capture.
Read only. No
effect on DPD
configuration.
clgcLoopOpen uint8_t Open or close the gain loop. 0 If true, the loop is
open and the TX
attenuators are
not updated.
Used to measure
a target gain.
clgcGainTarget_HundredthdB int32_t Set by user as the gain
target.
clgcFilterAlpha uint32_t Gain filter coefficient. 0 1 0.75 When it is 0, the
filter is disabled.
clgcLastGain_HundredthdB int32_t Unfiltered gain measured
when loop is open
Only valid for
user to retrieve.
clgcFilteredGain_HundredthdB int32_t Filtered gain measured
when loop is open
Only valid for
user to retrieve.
Each of these parameters are described in more details as the following:
numberOfSamples
It specifies the number of samples used per DPD/CLGC data capture with a limit of 4096. In general, the DPD/CLGC performance could
be improved if more samples are used. For TETRA1, currently, the Linearization Channel (LCH) is not supported so the
numberOfSamples should be set to 4096. When LCH is supported, the numberOfSamples could be changed to a different value. More
information will be provided in the future.
For LTE, the Number of Sample should be set to 4096 without frequency hopping.
additionalPowerScale
This parameter is used to scale the higher power terms during the calculation of the auto-correlation matrix using transmit data d(n). It is
used to keep the nominal magnitude of each of the power terms about the same to avoid ill condition of the correlation matrix. The
scaling factor could be defined as ≈ 2 × (()), where “std” stands for standard deviation. User could measure and then pass
the information through this parameter.
rxTxNormalizationLowerThreshold/rxTxNormalizationUpperThreshold
These are required parameters for the normalization of the magnitude and phase of the receive and transmit data. These thresholds are
used to pick a linear region for normalizing the data. The region chosen should be below the compression point but above the noise. In
the AM-AM and AM-PM plots shown in Figure 185, a possible choice of the linear region is highlighted in red. In general,
rxTxNormalizationUpperThreshold should be set to 0.5 of the peak signal amplitude and rxTxNormalizationLowerThreshold should be
set to 0.3 of the peak signal amplitude. Once they are set, the threshold values should be fixed and not vary from capture to capture.
Therefore, by knowing the peak transmit signal in dBFS, rxTxNormalizationUpperThreshold should be set to “peak Tx dBFS – 6 dB” and
rxTxNormalizationLowerThreshold should be set to “peak Tx dBFS – 10.5 dB”. Peak transmit signal is usually set at P1dB by adjusting the
Tx attenuation setting.
The user could enter those thresholds in dBFS through TES. If using API, the linear numbers should be used which can be calculated as
10
(threshold_dBFS/10)
.
detectionPowerThreshold
It is used to detect an invalid data capture for DPD/CLGC operation if a specified number of samples (countsLessThanPowerThreshold)
are below the defined power threshold.
detectionPeakThreshold
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