Ericsson MINI-LINK TN R3 ETSI, Техническое описание

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MINI-LINK TN R3 ETSI
• Radio Communication Channel (RCC) signal as an Amplitude Shift Keying
(ASK) signal.
In addition to the above, the cable interface includes an over voltage protection
circuit.
5.2.1.10 Demodulator
The received 140 MHz signal is AGC amplified and filtered prior to conversion
to I/Q baseband signals. The baseband signals are pulse shaped in a Nyqvist
filter and A/D converted before being demodulated.
5.2.1.11 Radio Frame Demultiplexer
On the receiving side the received composite data stream is demultiplexed and
FEC corrected. The frame alignment function searches and locks the receiver
to the frame alignment bit patterns in the received data stream.
Descrambling and FEC Decoding
Error correction is accomplished using FEC parity bits in combination with a
data quality measurement from the Demodulator. The descrambler transforms
the signal to its original state enabling the Demultiplexer to properly distribute
the received information to its destinations.
Demultiplexing
Demultiplexing is performed according to the used frame format. The
Demultiplexer generates a frame fault alarm if frame synchronization is lost.
The number of errored bits in the traffic data stream is measured using parity
bits. These are used for BER detection and performance monitoring. Stuffing
control bits are processed for the traffic and service channels.
Traffic
On the receiving side the following is performed to the traffic data:
• AIS insertion (at signal loss or BER
≤
10
-3
)
• AIS detection
• Elastic buffering and clock recovery
DCC
On the receiving side, elastic buffering and clock recovery is performed on
the DCC.
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