Safran CORTEX CRT Quantum, User Manual

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COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
© Safran Data Systems
This document is the property of
Safran Data Systems
.
It cannot be duplicated or distributed without expressed written consent.
Page 56
3.3.5.2.2. Pre Detection Diversity Combining

In Video Mode : the DCU has two separate outputs. Output # 1 can be routed to either a
low bandwidth telemetry unit or a high bandwidth telemetry unit with sub-carrier. Output # 2
is available for Tracking processing (DTR). Each DCU output can be separately
programmed to Channel A, Channel B, Best Channel or Combined Channels.

In PCM Mode : the DCU has one output. Output# 1 is connected to a high bandwidth direct
PCM IF receiver.
PCM Mode with dynamic Bit Rate Switch : a second direct PCM telemetry unit may be connected to the same
DCU output to demodulate another bit rate in the case of dynamic bit rate switch. TMU A has to be set with the
highest bit rate and TMU B with the lowest bit rate. The lowest bit rate has to be a sub-multiple of the highest bit
rate. Hence, the IFRs will remain locked during bit rate switch, the frame synchronizer of the corresponding TMU
becoming locked while the other one becoming unlocked.
Note : a status in the DCU monitoring table indicates which IF Receiver is Channel A and which one is Channel
B.
Channel A
Predetection filtering
Level measurement
Channel B
Predetection filtering
Level measurement
Combiner
Signal phase
alignment
PM,FM demodulation
Coherent AM
Non coherent AM
Polarization 1
Polarization 2
PRE DETECTION DIVERSITY COMBINING IN VIDEO MODE :
A
B
To :
IF Demodulation
mA + nB
(m + n = 100%)
Output 1
Output 2
Tracking processing (DTR)
Predetection
PLL
Video test outputs
Channel A
Predetection filtering
Level measurement
Channel B
Predetection filtering
Level measurement
Combiner
Signal phase
alignment
PCM/BPSK,
PCM/QPSK,
PCM/OQPSK
or PCM/PM
Polarization 1
Polarization 2
PRE DETECTION DIVERSITY COMBINING IN PCM MODE :
A
B
mA + nB
(m + n = 100%)
Output 1
To :
IF Demodulation
Predetection
PLL
Video test outputs
Figure 29: Pre detection Diversity Combining outputs