The ODU implements the following functions:
l
In the transmit direction, the ODU performs up-conversions and amplifications for the
analog IF signal coming from the IDU. After the IF signal is converted into the RF signal
with a specific frequency, the ODU transmits the RF signal to the antenna.
l
In the receive direction, the ODU performs down-conversions and amplifications for the
RF signal coming from the antenna. After the RF signal is converted into the analog IF
signal, the ODU transmits the IF signal to the IDU.
l
The ODU provides the control channel to receive control and management from the IDU.
l
The ODU provides the ATPC function.
l
The ODU provides rich alarms and performance events.
l
The ODU supports the detection of the ODU transmit power and the received signal strength
indicator (RSSI).
l
The ODU supports the detection of the ODU temperature.
l
The ODU supports the querying of the manufacturing information of the ODU.
l
The ODU supports the setting of mute/unmute.
1.4 Working Principle
The structures of various types of ODUs are basically the same. All of the ODUs work by the
same principle.
Block Diagram
Figure 1-3
Block diagram of the ODU system
Antenna port
CTRL
Tx IF
Rx IF
Cable port
PWR
Up-conversion
Multiplexer
O&M
uplink
O&M
downlink
DC
Down-conversion
AMP
LNA
Synthesizers
Duplexer
Rx RF
Tx RF
Signal Processing in the Transmit Direction
The multiplexer splits the signal coming from the IF cable into a 350 MHz IF signal, an O&M
uplink signal, and a -48 V DC power signal.
In the transmit direction, the IF signal is processed as follows:
1 ODU
OptiX RTN 600 ODU
Hardware Description
1-4
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Issue 06 (2010-05-30)