Band Selective Compact Repeater Block Diagram
Figure 5-2 shows a block diagram of the band selective compact repeater.
This diagram is applicable to repeaters for e.g. NMT, GSM, TACS/ETACS,
AMPS/DAMPS and CDMA systems.
Downlink signal path
The signal from the base station is received via the repeater BS antenna
and is forwarded through a directional coupler (DCC) to the ANT input of
a duplex filter (DPX). The signal from the HI output of the duplex filter
is, via the P126 port, fed to the BSC board. On the BSC board, the signal
is amplified in a low noise amplifier (LNA) and is then entered the band
selective amplifier circuitry.
The first mixer stage in the BSC amplifier, which is controlled by a
synthesizer, converts the received frequency down to the IF frequency.
The signal is then filtered by SAW bandpass filters and, not shown in the
RCC
BSC - UL
PA
LNA
P121
P122
BSC - DL
PA
LNA
P126
P128
P130
P112
P119
P130
DPX
MS
P118
P124
DCC
BS
ANT
LO
HI
HI
LO
ANT
DPX
BS
MSC
PSM
ANT
RCC
DPX
BAND SELECTIVE COMPACT REPEATER
BS
antenna
Base station
Telephone line
Modem
Modem
Battery
External alarm sensors
MS
antenna
BSC - control circuitry
Figure 5-2. Block diagram
ALLGON Systems AB
ALR Compact Repeater
Functional Description
VD203 67/EN - User’s Manual
Rev. 1A 2000-07
5 - 5