ETTC'2003 - SEE

All these sub-systems can be easily configured to provide new satellite transmission architectures.
In order to be as much as possible representative of the real system, the BST operates main system
equipment at the right frequency band. However, most of the BST sub-systems and components use
interfaces defined around an intermediate frequency (IF) in C band (3.7-4.2 GHz). These common IF
interfaces improve the bench modularity as it gives the ability to integrate only a part of the BST
sub-systems or components in order to customise the bench depending on the system architecture and the
kind of analysis to perform. The frequency conversions from C band to system frequency band are
designed not to introduce degradations on the emulated satellite link.
Another aspect of bench development concerns the racks input/output connectors which are all defined as
SMA connectors in order to support the introduction of specific transmission components such as
commercial integrated LNB, filters, etc. , using standard cables.
The bench could be configured to represent at the same time the forward and return link of a satellite
telecommunication system. This is performed by the representation of the antennas that will be virtually
splitted in two.
System Transmission Bench
3 CNES SPECIFIC BENCH DEVELOPMENTS
Specific developments have been made in order to generate and control different possible degradations of
the link budget.
3.1 EMITTER RACK
The REM (Emitter Rack) is a multimission 4-channel test modulator. As an extremely wide rate-range
modulator, it is capable to provide from 1.6 kbauds to 100 Mbauds signals (400 Mbit/s in 16QAM mode)
in the 3.7 to 4.2 GHz band. Designed by CNES, the REM has been developed for CNES by the R&D
laboratory of SMP.
The REM generates in parallel 4 modulated signals with the following parameters:
BPSK/QPSK/OQPSK/QAM16 modulations
SINC/SRRC/User defined filtering
1 Hz to 1 MHz output switching with programmable cycle ratio to simulate TDMA burst
Step and continuous attenuators to provide flexible power controls
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