User's Manual

Table Of Contents
10 System Description
Chapter 1 - System Description
1.2.5.4 4
th
Order Diversity
Multiple channel configuration with fourth order diversity allows a single sector
coverage by a single AU-IDU with 4 ODUs. In each sector, both space and
polarization diversities are implemented, using dual polarization slant antennas.
The channels are paired: channels 1 and 2 form one pair, channels 3 and 4 form
the second pair. The two ODUs connected to each pair are connected to the same
dual polarization antenna. The same frequency and transmit power are set for all
four ODUs. All ODUs served by the same AU-IDU share a common MAC and
modem.
1.2.6 Power Feeder
The Base station’s regular PIU can support a maximum current of 35 A (@-40.5
VDC). Using proper design considerations, up to eight AU-ODU-HP units can be
powered directly from the Base Station (via the back panel and AU-IDUs). The
High-Power PIU can support a maximum current of 58 A, enabling support of up
to 20 AU-ODU-HP units. The ODU Power Feeder
is used as an additional power source providing
power (-48 VDC) to AU-ODU-HP High Power
ODUs. It transfers transparently all signals
between the AU-IDU and the ODU, while
injecting DC power received from an external
source. Each ODU Power Feeder unit can serve
up to four High Power ODUs. Up to three ODU
Power Feeder units can be installed in a 1U high Power Feeder panel.
The following tables displays the number of ODUs and Power Feeder modules
required for various radio configurations and different PIU types: