Ericsson RBS 2106 Hardware Reference Manual page 333

4.1 CPU System
The CPU system is a control unit in the RBS. It consists of a CPU, support
logic, memory and logic for handling the interfaces.
4.2 DSP System
The DSP system performs all baseband signal processing necessary for one
TRX. For downlink, this includes Terrestrial Protocol Handling (TPH),
encoding, ciphering and burst generation. For uplink it includes equalization,
combining, decoding and TPH.
4.3 Radio Control System
The RC system is responsible for synchronizing and controlling the different
parts of the radio, for modulation and D/A conversion of the data to transmit,
for filtering the received radio signal with a channel selective filter and for
compensating the RX and TX delay and gain variations.
The RC system is seen by the rest of the RBS as the front end to the radio,
which can be asked to transmit a burst of data using a selected modulation, or
asked to receive a burst using a selected digital filter.
All time critical radio control functions are performed by the RC system and no
computing support is required from the CPU system on a real-time basis.
4.4 Radio System
Each radio system contains two radio receivers and one radio transmitter
including power amplifiers.
The radio receiver receives RF modulated uplink data from one or two
diversity branches and sends it to the RC system.
The radio transmitter generates the RF downlink signal from the modulated
baseband signal. It then sends the RF signal to the power amplifier, which
amplifies the downlink RF signals.
5 Interfaces
The dTRU has the following external interfaces:
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CDU-TX control bus, IOM bus
IOM bus, LEDs and buttons
5(6)
EN/LZT 720 0242 R1A