Analog Devices ADRV9001 User Manual page 169

Preliminary Technical Data
Tap 2: b = 1, b = 1, b
2,2,0 2,2,1
Tap 3: b = 0, b = 1, b
3,2,0 3,2,1
If using an array B for 4 taps and for each tap using a byte to represent the above setting (the least significant bit represents the 0th power
term), it is clear that the default setting is equivalent to B[0] = 0x1F, B[1] = 0x7F, B[2] = 0x1F and B[3] = 0x1E.
The connections from the 4 outputs are combined to produce the final output, x(t) as the following:
x(t) = TAP [|d(t)|] × d(t) + {TAP
0
changeModelTapOrders
This flag is used to provide user an option to select the default model tap orders or choose a customized model tap orders. If this flag is
set to be "TRUE", the next field in the data structure "modelOrdersForEachTap", should be used to set the model tap orders for the
specified channel. If it is "FALSE", then "modelOrdersForEachTap" will be ignored and it will use the default tap orders as discussed
(B[0] = 0x1F, B[1] = 0x7F, B[2] = 0x1F and B[3] = 0x1E).
modelOrdersForEachTap
This is an array of bitmaps
setting. It provides user an option to customize the order so that a power term could be included or excluded in the polynomial to better
model the power amplifier. Table 73 are recommendations for setting this field. The user could try those suggestions and find out the
best model through tests. The method of selecting the best model tap orders is discussed in the DPD Tuning and Testing section as a part
of DPD tuning recommendations.
Table 73. Suggested Model Orders for Narrow-Band Waveforms
Taps Model Orders for Each Tap
Tap 1 B[1] = 0x1F, 0x3F, 0x7F, 0xFF
Tap 0 and Tap 2 B[0] = B[2] = 0x03, 0x07, 0x0F, 0x1F, (Tap 0 and Tap 2 should be the same.)
Tap 3 B[3] = 0x0, 0x02, 0x06, 0x0E, 0x1E, 0x3E
The user could configure the changeModelTapOrders and modelOrdersForEachTap through TES, as shown in Figure 149 and Figure 150.
Figure 149 shows the default model tap configuration and Figure 150 shows a customized model tap configuration which is equivalent to
B[0] = 0x07, B[1] = 0x7F, B[2] = 0x07 and B[3] = 0x06. (Note Tap 0 and Tap 2 should always be the same. For simplicity GUI uses X to
represent )
= 1, b = 1, b = 1, b
2,2,2 2,2,3 2,2,4 2,2,5
= 1, b = 1, b = 1, b
3,2,2 3,2,3 3,2,4 3,2,5
[|d(t − 1)|] + TAP [|d(t − 2)|]} × d(t – 1) + TAP
1 3
for each tap t (t=0 to 3), formulated in the same way as discussed above for the default
Figure 149. Configuring Default Model Tap Order Through TES
Figure 150. Configuring Customized Model Tap Order Through TES
Rev. PrA | Page 169 of 253
= 0, b = 0, b = 0
2,2,6 2,2,7
= 0, b = 0, b = 0
3,2,6 3,2,7
[|d(t − 2)|] × d(t – 2)
2
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