Safran CORTEX CRT Quantum User Manual page 158

c- External Input to Viterbi Decoder (TMU table/offset 26 = 2. GUI: Frame Sync. Input = Ext. Vit.
1) :
Aux. inputs
IF inputs
PM, FM
Aux. inputs
demodulator
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© Safran Data Systems
COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
BPSK S/C,
PCM/PM, PCM/FM Bi-phase, DM-M
demodulator decoder
Bit synchronizer
Video
out
Figure 38: TM Chain : I/O Ports (HBW with sub-carrier)
Phase ambiguity solving is by the frame synchronizer or by the differential decoder (if the
PCM code is NRZ-M or NRZ-S).
Test points and external input to the Frame Synchronizer or Viterbi Decoder are available if
one of the downlink data I/Os Test Sets is enabled. See section 2.3.4.2, Annex 5 and TMU
monitoring table, status offset 26 for more details.
In the case of external Viterbi input (scenario c), only hard-decision is available, with the
corresponding performances.
Auxiliary inputs: restricted to noise & spurious-free signal with limited amplitude variations.
Direct input to the PSK Demodulator: set the IF Receiver to « By-pass » mode and select
Auxiliary port # 1 or # 2.
Option: Direct input to the PSK Demodulator is also accessible using offset 29 in the
telemetry unit table with value 1 or 2.
Direct input to the Bit Synchronizer: set the IF Receiver to « By-pass » mode and the SCF
to 0 on the Telemetry Unit. Select Auxiliary port # 1 or # 2.
Option: Direct input to the Bit Synchronizer is also accessible using offset 29 in the
telemetry unit table with value 1 or 2.
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(Option)
I in
Viterbi Differential
decoder
(Option)
Safran Data Systems
.
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
Frame
decoder Synchronizer
Differential
encoder
Invert/
swap
I out
(Option)
Page 78