Technical Manual
Airbridge BTS3606A CDMA Base Station
System Description
Chapter 3 Product Architecture
3-4
BSC
Baseband subsystem
Power supply and environment monitoring subsystem
RF subsystem
Abis
interface
Um interface
MS/AT
Antenna subsystem
220 V AC
or 110 V AC
BTS3606A
Figure 3-3
BTS3606A system structure
3.3.1 Baseband Subsystem
The baseband subsystem comprises the BCKM, BCIM, CCPM, CECM, and HPCM. It
has the following functions:
l
Provide Abis interface to process the Abis interface protocol.
l
Provide a fiber interface to the RF subsystem to process the Um physical layer
and Common Channel (CCH) MAC layer protocols.
l
Implement modulation/demodulation of CDMA2000 1x and 1xEV-DO baseband
data and the coding/decoding of CDMA channels.
l
Provide synchronization clock signal to the BTS.
l
Perform system resource management, operation and maintenance, and
environment monitoring.
3.3.2 RF Subsystem
The RF subsystem consists of the CTRM, CHPA, CDDU, and CPCM. It has the
following functions:
I. On the forward link
The RF subsystem
1) Performs power-adjustable up-conversion and linear power amplification on the
modulated transmit signals.
2) Completes power combination (optional).
3) Filters the transmit signals.
4) Finally sends the signals to the antenna subsystem.
II. On the reverse link
The RF subsystem
1) Filters the signals received by the BTS antenna to suppress the out-band
interference.
2) Performs low-noise amplification.
