Bts Transceiver Module (Btrm) - Huawei Airbridge cBTS3612-1900 User Manual

User Manual
Airbridge cBTS3612 CDMA Base Station
&
Note:
The above figure illustrates the RF configuration for 450MHz band. For 800MHz band, the duplexer
would be CDU. For 1900MHz band, the duplexer would be DDU.
In forward link, it performs power adjustable up-conversion and linear power
amplification to the modulated transmission signals, filtering the transmission signals
to meet the corresponding air interface standard.
In reverse link, it filters the signals received by the BTS antenna to suppress
out-band interference, and then performs low-noise amplification, noise factor
adjustable frequency down-conversion, and channel selective filtering.

2.3.2 BTS Transceiver Module (BTRM)

BTRM is in charge of modulating/demodulating of baseband signal, Analog/Digital
and Digital/Analog (AD/DA) conversion, digital up/down conversion and radio
up/down conversion.
I. Structure and principle
BTRM consists of BTS Intermediate Frequency Unit (BIFU) and BTS Radio up-down
Converter Unit (BRCU). Its structure is shown in Figure 2-14.
BIFU
BHPA
BHPA
PSU
BTRM
+27V
PSU
Figure 2-14 Structure of BTRM
CPU
Down
ADC
FIR converter
&
DAGC Down
ADC
converter
Up
FIR DAC
converter
Power
BRCU
Main receiver
Clock
Filter Diversity receiver
Filter
Filter
2-25
System Description
2 Hardware Architecture
Local oscillator
Transmitter
RLDU
RLDU
BHPA