Safran CORTEX CRT Quantum - Page 48

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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Page 23
 2Bn Carrier PLL BW (CRT XL Quantum)
0.03, 0.1, 0.3, 1 and 3 % of symbol rate
 2Bn Carrier PLL BW (CRT eXplorer)
0.01, 0.03, 0.1, 0.3, 1 and 3 % of symbol rate
User configurable (0.001% to 10%)
 Bit synchronizer PLL BW (2 Bn) Carrier loop bandwidth /10
 BER degradation ≤ 1 dB vs theory if BR < 10 Mbps, ≤ 2 dB if BR < 40 Mbps
In case of BP, DM: ≤ 1 dB if BR < 5 Mbps, ≤ 2 dB if BR < 10 Mbps
(always ensure the received spectrum fits to the 50-90 MHz IF Receiver
input bandwidth).
 Synchronization threshold ≤ 0 dB (Eb/No) for symbol rates ≥ 1 ksps (10 dB at 100 sps)
 Eb/No measurement Yes (0.5 dB accuracy)
1.6.1.4. Telemetry Processing
1.6.1.4.1. Low Bandwidth Telemetry
 Input IF Receiver output
 Demodulation BPSK (direct bit synchronization available)
 Sub-Carrier Frequency 40 Hz to 128 kHz (512 kHz with LBW extension license)
 Bit Rate Minimum: 10 bps or 7 bps with PACK-EXT license (NRZ code)
Maximum: 25 kbps or 64 kbps with LBW extension license
 Number of sub-carriers ≤ 6
 Bandwidth Automatically adjusted to the selected bit rate and sub-carrier frequency
 PSK demod./Bit sync. loop BW 10% / 10 % (Ultra Wide)
% of the Bit Rate 1% / 1% (Wide)
0.3% / 0.1% (Narrow)
 Acquisition threshold (*) Eb/No ≤ 0 dB (narrow BW), 2 dB (wide BW), 10 dB (Ultra Wide BW)
(*) at bit sync level
 Viterbi decoding Rate 1/2 according to CCSDS 131.0-B-3 (§ 3.3)
Constraint length 7.
 Viterbi depuncturing Rate 2/3, 3/4, 5/6, 7/8 CCSDS 131.0-B-3 (§ 3.4)
From 1/2 rate punctured code. Constraint length 7.
 PCM coding BP-L/M/S, NRZ-L/M/S
 BER degradation ≤ 1 dB vs theory (typical)
 Eb/No measurement Yes