Tektronix OM4006D, User Manual

Page: 90 / 205

Taking measurements
Multicarrier support (MCS) option
As network operators seek to increase the capacity of their fi ber-optic transmission
systems, moving wavelength division multiplexing (WDM) signals closer together
is an attractive option. The densely packed signals are more readily separated
using digital
fi lters after coherent detection rather than more coarse WDM fi lters.
This also simpli fi es routing since more is under digital control.
A group of tightly packed WDM channels is sometimes called a superchannel
because of the many channels. It is also known as a multicarrier signal since the
various channels come from separately modulated carriers. In this document
the term multicarrier refers to the group, where channel refers to an individual
modulated carrier.
The optional MCS function displays the results of multiple channels within a
multicarrier signal at the same time. The MCS option can scan automatically
between channels. Alternatively, the scan may be performed manually, and the
OUI displays the results with the appropriate channel label by recognizing the
channel based on the frequency entered by the user.
The Multicarrier Setup
window
The Multicarrier Setup window allows the user to de fi ne the carrier channel plan,
to start and stop an automatic scan, and to de fi ne which channels will be included
in separate axis plots Multicarrier Eye and Multicarrier Constellation. The
window is divided into two sections: Multicarrier channel list and Multicarrier
display layout. The absolute channel list is shown on the right, the relative version
on the left.
When the MCS feature is enabled in the USB HASP key, the OUI displays the
Mulitcarrier Setup button on the Setup ribbon.
Figure 5: Multicarrier Setup button (Home ribbon)
Click the Multicarrier Setup button to open the Multi Setup window.
66 OM4000D Series Coherent Lightwave Signal Analyzer