Fig. 3.6 Patrx Block Diagram - Siemens BS-240 Technical Description

Information
Base Station System
Rx input
(diversity)
Tx output
A30808-X3247-L14-2-7618
PWSTG
Fig. 3.6 PATRX Block Diagram
The functional sub-unit PATRX consists of three PCBs:
– RXA: Analogue receiver board with modules RXFEM, RXFED, RXLO and LTL
– TXA: Analogue transmitter board with modules MODUP, TXLO, PWRDET
– PWRSTG: Power stage including heat sink
Signal Processing Unit (SIPRO)
The SIPRO-Board is a part of the Carrier Unit. It contains all digital functions of the
carrier unit namely
•
Signal Processing in uplink and downlink
•
Control of RF on PATRX
•
Baseband and synthesizer hopping
•
Channel Control
•
Radio Link Control
•
O&M parts relevant for carrier unit
•
Link to Core via CC link
Additionally, following analogue functions are located on SIPRO:
•
Analogue to digital conversion (IF)
•
Digital to analogue conversion (baseband)
•
Local clock of CU
Due to the analogue functions, SIPRO is specific for the different frequency variants.
There are two types of SIPROs (one for GSM 850, GSM 900, one for GSM 1800, GSM
1900).
Fig. 3.7 illustrates the principal data flow on SIPRO:
– receives two (diversity!) IF signals from the receiver, then analogue to digital conver-
sion takes place. The next step is digital downconversion to base band and filtering.
The output of the filter is equalized. The soft decisions from the equalizer then are
deciphered. The deciphered data stream is processed by the decoder. After
decoding (including bad frame indication), the data stream is packed into TRAU
RXFEM
RXFED
RXLO
LTL
TXLO
MODUP
PWRDET
Technical Description (TED:BSS)
BS-240/241
to SIPRO for
downconversion
to baseband
LCLK from SIPRO
RF Control
from SIPRO
GMSK modulated
signal from SIPRO
TXBB
from SIPRO
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