1-6 • Introduction 8018653 1.1
Antennas Each BTS site has a single transmit antenna and two receive antennas.
There are several antenna types and configurations that are chosen based
on environmental, regulatory, and site-specific requirements. Generally,
the omnidirectional antennas used are dipole collinear array types; the
sectorized antennas are available as panel or collinear arrays.
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CUMC
STACK
RFMC
STACK
Figure 1-5. BTS stacks (typical)
RFMC RFMC equipment (shown in figure 1-5) perform the following functions:
•Amplify the RF carrier from one (or more) CUMCs.
• Combines high power RF carriers from the amplifiers and inter-
faces to the transmit antenna.
CUMC CUMC equipment transmit functions include the following:
•Perform baseband processing and transmit filtering of the digitized
transmit voice signal based on the operational mode (AMPS,
TDMA, or E-TDMA).
•Modulate, upconvert, and amplify the transmit carrier before send-
ing the signal to the RFMC.
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