Sagem SAGEM-LINK F - Cable Interface Module Description; Outdoor Unit Description

SAGEM-LINK F 288055571-04
Installation and Operation Manual
Page 112/142
Issue 04 : July 2005
Reproduction and communication prohibited without the written permission of Sagem Communication
5.5 – Cable Interface Module Description
The Cable Interface module, which is frequency independent, is plugged into an IDU rack. It consist
of :
• ODU cable interface which multiplexes in frequency 5 signals in order to transmit them on a
single 50 ohm coaxial cable. These signals are :
- DC voltage (-48V) to supply the ODU
- Transmit IF which is a QPSK or a 16QAM modulated carrier at 350 MHz frequency
- Telemetry uplink (5.5 MHz) which contains all control signals from IDU to ODU
- Receive IF (modulated carrier at 140 MHz)
- Telemetry downlink (10 MHz) which carries information returned from the ODU to the IDU
(alarms, receive signal level).
• A 350 MHz QPSK / 16QAM modulator including :
- An Reed Solomon FEC encoder (204, 188, 8)
- A scrambler and a digital filter
- A 350 MHz I/Q modulator
• A 140 MHz QPSK / 16QAM demodulator including :
- Zero IF down conversion
- Adaptive equalizer
- Carrier and Clock digital recovery
- Reed Solomon FEC decoder
- Descrambler
- BER indication
• A DC- DC power supply, feeding the cable interface module and the rest of the IDU. In 1+1
systems, the IDU is supplied by two power supply from the main and the standby cable
interface modules. A hot swap feature is implemented in order to avoid any disturbance on
traffic while being in maintenance operation.
5.6 – Outdoor Unit Description
The Outdoor Unit, which is capacity independent, is an integrated unit consisting of :
• IDU cable Interface which is the reverse of Cable Interface module :
- DC voltage Input (-48V) to supply the ODU
- 350 MHz Transmit IF input
- Telemetry uplink (5.5 MHz) which contains all control signals from IDU to ODU
- 140 MHz Receive IF output