Chapter
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12-3
RFE module is the main module connecting the internal system of RFS in the
BTS and the external antenna of the BTS. Its terminal port is the RF port at the
top of the BTS and the test port of the BTS for system testing. It has great
influence on the receiving sensitivity and exit transmitting power of the whole
BTS system.
10. HPA
HPA (High Power Amplifier) amplifies the power of TRX’s forward
transmission signals so that the signals go through the duplex filter of RFE at a
proper power value and then transmitted by antenna into the cell. The CDMA
system requires that HPA should have certain linearity.
11. TRX
TRX is the junction connecting RF and baseband signals. One TRX corresponds
to one sector of one carrier. In the reverse channel, TRX receives the main and
diversity receiving signals of the sector, conducts down conversion, median
frequency filtering, AGC processing and I/Q demodulation on these signals to
convert the received modulated RF signals into baseband I/Q signals. In the
forward channel, TRX conducts I/Q modulation, median frequency filtering and
upward conversion on the baseband I/Q signals to convert them into modulated
RF signals, while also performing TPTL power control.
12. PSMD
PSMB is the main power board of the whole BTS.
13. PSMC
PSMC (±12V power) conducts DC/DC conversion from
-
48V to ±12V. The
max. output of +12V is 25A and that of
-
12V is 8A, both providing the RFS
with working power supply in the 1+1 backup mode. This module is also
available with the remote control and teleaction functions.
14. PPM
PPM (27V power board) conducts DC/DC conversion from
-
48V to +27V. It
has protection functions for input over/under voltage, output over/under voltage,
output over-current, and over-temperature. It employs the
temperature-controlled forced cooling structure and is also available with the
remote control and teleaction functions. Output current of one PPM is 25A.
