Safran CORTEX CRT Quantum - SOQPSK Demodulation

COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
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3.3.1.2.4. SOQPSK Demodulation
Shaped Offset QPSK (SOQPSK) is a constant envelope Continuous Phase Modulation (CPM). It is derived from
OQPSK with the addition of a baseband filter that further reduces side lobe levels and spectral bandwidth. Filter
shapes are defined for SOQPSK-TG, -MIL, -A and –B.
SOQPSK can be combined with a differential decoder to remove the phase ambiguity of the modulation. BER will
be increased by a factor of two.
-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
-80
-70
-60
-50
-40
-30
-20
-10
0
Frequency (Bit Rates)
Relative Power Spectral Density (dB/Hz)
SOQPSK-MIL
SOQPSK-B
SOQPSK-TG
SOQPSK-A