Andrew Node G 930, User Manual

Page: 29 / 66

4 Functional Description
ID No: 7164491 Page 29
4. FUNCTIONAL DESCRIPTION
4.1. DIGITAL ARCHITECTURE
figure 4-1 Digital architecture of one path of Node G
The Node G is designed to amplify signals between multiple mobiles and a base
station. The unit consists of a filter and amplifier chain in the downlink and one filters
and amplifier chains in the uplink. The uplink and downlink paths are connected via a
duplexer on both ends of each path.
In the uplink path, a signal originating from the mobile is separated from the downlink
signal via the UL IN duplexer. It is then amplified by an integrated low noise amplifier
(LNA) and forwarded to the digital channel module (DCM). The signal will be divided
in the DCM to the two channels of the module. The DCM down-converts the signals
to base-band, digitally filters them, amplifies them and then up-converts them in the
two channels. In addition the interference cancellation technology is implemented in
the DCM. Finally, the signals are sent to the final amplifier, summarized and
combined with the downlink input signal in the DL IN duplexer.
In the downlink path, a signal originating from the base station is separated from the
uplink signal in the DL IN duplexer. It is then amplified by an integrated low noise
amplifier (LNA) and forwarded to the digital channel module (DCM). The signal will
be divided in the DCM to the two channels of the module. The DCM down-converts
the signals to base-band, digitally filters them, amplifies them and then up-converts
them. In addition the interference cancellation technology is implemented in the
DCM. Finally, the signal is sent to the final amplifier and combined with the uplink
input signal in the UL IN duplexer. The DCM is also responsible for communication
and control of the entire unit.
DCM
Front End
Channel 1 Down Converter
Channel 1 Digital Path
Up Converter LO
AGC_3
AGC_2
AGC_1
Shared
Duplexer and LNA
Shared
PA and Duplexer
Channel 1 Up Converter
Down
Converter
LO
Switch
VCO and Synthesizer 1 VCO and Synthesizer 2
Ref VCO and Synthesizer
To Module 2-4
To
Module 2-4
NSB DSP &
Controller
This Section is
Shared Among
all Modules
A/D
A/D
A/D
D/A
Ref AGC
B0161ALA