Normal Iq Output Mode - Analog Devices ADRV9001 User Manual

UG-1828
Figure 130 illustrates the functional diagram of the Resampler, the Resampler resamples the incoming received signal, by reconstructing
intermediate samples between every 2 inputs samples according to the re-sample phase parameter,
In the frequency domain, the ideal digital Resampler has the transfer function as below:
where B is the maximum bandwidth of the input signal. Filtered by the ideal resampling filter, the input signal, x(kT
x
the output signal y(kT ) = x((k + μ) × T
S
Scanning the sampling phase μ from 0 to 0.5, the maximum magnitude difference of the frequency transfer function between the
Resampler and the ideal digital resampler is collected and plotted at the upside of Figure 131. The maximum phase error is collected and
plotted at the downside of Figure 131.
The Resampler can be used in both the wideband and narrowband modes.
50
40
30
20
10
X = 0.1
Y = 5.189e-05
0
0 0.1
0.5
0.4
0.3
0.2
0.1
X = 0.1 X = 0.2
Y = 1.589e-05 Y = 4.893e-05
0
0 0.1
Note: The resampler configuration is not supported by current ADRV9001 software release yet.
Round Module
Round in rxnbdem is to map the ADRV9001 internal datapath bit-width to the Rx SSI output. This module cannot be bypassed.
The Round module outputs 16-bit I data and 16-bit Q data to the Rx SSI output. If required, the Round module can output 16-bit I data
to the Rx SSI output with the 16-bit output Q data set as '0'.

NORMAL IQ OUTPUT MODE

The Normal IQ Output mode is applicable for both wideband and narrow band as the frequency discriminator bypassed. Except the
Rounding, all other modules can be bypassed. See Figure 132 ADRV9001 Rx narrow-band demodulator can be the common output stage
of Rx channel.
S
I, Q
SUB-FIR3
µ
16: S1.15
Figure 130. Functional diagram of the Resampler
MAX MAGNITUDE ERROR FOR µ = [0:0.001:0.5]
X = 0.2 X = 0.3 X = 0.4
Y = 0.00081 Y = 0.004165 Y = 0.01989
0.2 0.3
NORMALIZED FREQUENCY (× Rad/Sample)
MAX PHASE ERROR FOR µ = [0:0.001:0.5]
X = 0.3 X = 0.4
Y = 0.0002133 Y = 0.0007297
0.2 0.3
NORMALIZED FREQUENCY (× Rad/Sample)
Figure 131. Maximum Magnitude/Phase Error of the Resampler
SUB-FIR2
SUB-FIR1
X = 0.7
X = 0.5 X = 0.6
Y = 1.302
Y = 0.09938 Y = 0.0407
0.4 0.5 0.6
X = 0.7
X = 0.6
X = 0.5
Y = 0.03144
Y = 0.01102
Y = 0.02958
0.4 0.5 0.6
Rev. PrA | Page 152 of 253
Preliminary Technical Data
SUB-FIR0
I, Q
X = 0.9
X = 0.8 Y = 8.558
Y = 3.459
0.7 0.8 0.9
X = 0.9
Y = 0.1648
X = 0.8
Y = 0.07514
0.7 0.8 0.9
.
), is converted to
S
1.0
1.0