Service Manual

GSM-204-323
RF equipment detail
31st Oct 01
Technical Description: Horizon macro outdoor
68P02902W02-A
CONTROLLED INTRODUCTION
Tech. 5–3
Transmit (Tx)
RF hardware
Transmit RF hardware consists of Tx blocks in appropriate combinations to meet
requirements of antenna sharing for the transceivers.
CTU Tx role
The CTU provides the following transmit functions:
 Transmit tuning (on a timeslot basis) for generation of any transmit
channel RF frequency.
 Encoding transmit data output.
 Digital modulation of transmit data onto the transmit radio channel signal.
 Final RF power amplification and output power level control of the transmit
radio channel RF signal.
 Channel encoding of the data to be transmitted, interleaving signal and
traffic channel data, as defined by ETSI.
Rx/Tx single
antenna
duplexing
Duplexers allow a single antenna to be used for both transmit and receive
operations. Duplexers exist within several of the transmit blocks. Normally
duplexed RF signals are used through one antenna, with a second receive
antenna to provide diversity.
CAUTION
If a single antenna (non–diversity) is required, the duplex
antenna RF receive cable from the transmit block must be
connected to the RxA path at the SURF. Simply switching
off diversity at the OMC-R without the correct SURF
configuration will cause a loss of reception.