GDI COMMUNICATIONS Extreme Copper XC-RP300, Owner'S Manual

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Link Configuration Page
The Link Configuration window shown in Figure 23 allows access to the PMD (Physical Media
Dependent) registers of the VDSL Modem. Both local and remote modems (if available and
synchronized) can be addressed by this window.
The following functions are available within the Link Configuration page:
Customized Settings:
If this option is selected,
the user has access to the
e n t i r e b a n d w i d t h v i a
adjustable constellations
and interpolations as well
a s c a r r i e r f r e q u e n c y
settings. Thus you can
find the appropriate line
r a t e f o r a p a r t i c u l a r
application.
Use Recommendations: In
this option, the user can
change the line rate of the
m o d e m b y s e l e c t i n g
approved constellations
and interpolations.
Line Rate: Line rate depends
on the on-board crystal.
The line rate depends on
the selected QAM
constellation and
interpolation.
Figure 23 Link Configuration Page
Line Rate is calculated as follows:
Line Rate = Baud Rate * N [Mbps] with:
Baud Rate = fsample / interpolation [Symbols per second]
N = log2(QAM size) [Bits per symbol]
Example: Fcrystal = 19.44 MHz, QAM64, Interpolation 12
Baud Rate = 19.44 MHz / 12 = 1.62 Symbols per second
N = log2(64) = 6
Line Rate = 1.62 Symbols per second * 6 = 9.72 Mbps
Note see Line Rate tables 2 and 3
Interpolation: This drop down menu provides access to all possible interpolation settings for the
different QAM selections. If ’Use Recommendations‘ is chosen it displays the interpolation
corresponding to the selected line rate.
Constellation: This drop down menu allows you to select one of the supported QAM constellations. If
’Use Recommendations’ is chosen it displays the QAM constellation corresponding to the selected
line rate.
Carrier Frequency: Here the carrier frequency for the upstream and downstream band can be selected.
If ’Use Recommendations’ is chosen it displays the default carrier frequency.
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