User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-13
Multiplex/demultiplex
module
Baseband
processing module
CPU module
Backplane bus
module
Power module
BCPM
Control bus
Clock module
BRDM
Data bus
Data bus
Backplane
bus
RS232
BCKM
High-speed
data bus
Figure 2-6
Structure of BCPM module
1) Multiplex/demultiplex module
In forward direction, baseband data in the channel processing board are multiplexed
into high-speed signals and sent to radio side in the form of differential signals. In
reverse direction, the high-speed differential signals are demultiplexed and sent to
baseband processing chip.
2) Baseband processing module
The QUALCOMM new generation processing chip is used to perform forward and
reverse baseband data processing. With the help of in-board and inter-board data
daisy chains, channel processing capability is increased greatly. Maximal 6 sectors
can be supported.
3) CPU module
The high performance control CPU on BCPM mainly processes the forward &
reverse high-speed traffic data and control data and reports board status. At the
network side, the processing module receives control signaling, receives/transmits
ATM cells and communicates with BSC through E1 interface. At the radio side, it
controls the dedicated baseband processing chip to generate orthogonal (IQ) data.
After multiplexing, the data pass BRDM as high-speed differential signals, to
implement data exchange with radio side.
