Reference Manual

Table Of Contents
Product Description 9 (33)
SRN/X-00:146 Rev B 2001-05-16 © Ericsson. Commercial in confidence
Configuration Switch Unit (CXU)
The task of the CXU is to cross connect between the CDU and the dTRU in the receiving
path. The CXU makes it possible to expand or reconfigure a cabinet without moving or
replacing any RX cables.
Figure 5. Configuration Switch Unit.
The RX inputs/outputs on the dTRU and the CDU are placed in such positions that they
minimise the amount of cable types for connecting the CXU with the dTRU/CDU.
Combining and Distribution Unit (CDU)
The CDU combines the transmitted signals from the transceivers and distributes the
received signals. Duplex filters are included in the CDU. A measuring coupler, providing
forward and reflected power measurements for Voltage Standing Wave Ratio (VSWR)
calculations is located in the CDU. Two different CDU types exist to support all the
configurations.
With hybrid combining, CDU-G, for 800, 900,1800 and 1900MHz. Allows base band
or synthesised frequency hopping.
With filter combining to support large configurations, CDU-F, for 900 and 1800 MHz.
Allows base band frequency hopping. CDU-F is optimised for giving large
configurations maximum output power on minimum number of antennas.
Figure 6. CDU-G and CDU-F.
Duplex filters allow both receiver and transmitter path connections to a common antenna.
The duplex configurations minimise the number of required feeders and antennas as well
as the combining loss in the transmission path.
The different CDU types are further described in the Radio Specifications for the different
frequencies.
The CDU-G and CDU-F are hardware prepared to support EDGE.