User Manual
Airbridge cBTS3612 CDMA Base Station
System Description
2 Hardware Architecture
2-12
IV. Index
The board size is 460mm
%
233.35mm,
powered with +27V,
power
consumption<10W.
2.2.4 Channel Processing Module (BCPM)
I. Overview
BCPM is logically located between BRDM and E1 interface board on BTS. BCPM is
the service processing board of the system with 12 equipped in full configuration.
Data of various forward channel traffic and reverse channel traffic are processed by
this board. BCPM also processes digital signals, including encoding/decoding
baseband signals and one-time modulation and demodulation of baseband signals.
In addition, it processes high layer control signals. The main functions are as
follows:
l
In forward direction, after ATM cell data from the network side are processed by
the high performance processor, BCPM performs functions such as encoding
(convolutional code, TURBO code), interleaving, spread spectrum, modulation
and data multiplexing, and converts them into high-speed signals. Then the
signals are processed by a dedicated processing chip and transmitted through
the radio interface side of the channel processing board.
l
In reverse direction, data received by BCPM are demultiplexed, demodulated,
de-interlaced and decoded (convolutional code, TURBO code). Then under the
control of the high performance processor, the data are sent to BSC via E1
interface in the form of ATM cells.
l
BCPM supports in-board and inter-board daisy chains, forming a
resource-processing pool.
l
High performance processor, two kernels, internal cache, level-2 cache can be
attached externally at the same time to improve processing capacity.
II. Structure and principle
BCPM module comprises the following parts as shown in Figure 2-6: