COMMAND RANGING & TELEMETRY UNIT CORTEX
CRT QUANTUM USER'S MANUAL
Ref. DTU 100042
Is.Rev. 5.17
Date: Dec.
03, 2021Sept. 30, 2021
This document is the property of Safran Data Systems.
It cannot be duplicated or distributed without expressed written consent.
3.3.6.6.2. PCM/BPSK Square/PM (Low or High Bandwidth)
The previous formulas are valid but you need to replace the term 10 log (2J
1
2
) by 20 log (sin Ф),
You can see the NASA document here for more information:
https://deepspace.jpl.nasa.gov/dsndocs/810-005/205/205D.pdf
3.3.6.6.3. High Bandwidth Direct PCM (PCM/PM)
Telemetry only:
With = modulation index
3.3.6.6.4. High Bandwidth Direct PCM (BPSK)
Telemetry only:
3.3.6.7. LDPC Decoding
Licensing:
Implementers should be aware that the codes optimized for deep space applications are covered by US Patent
7,343,539.
Potential user agencies should direct their requests for licenses to:
Office of Technology Transfer,
California Institute of Technology,
1200 E. California Blvd., Mail Code 210-85,
Pasadena, CA 91125
LDPC and error-correction by the CORTEX CRT-DS complies with CCSDS recommendation CCSDS 131.0-B-3.
The LDPC decoder uses 6 bits input quantized soft values.
The following coding characteristics should be used:
Payload block size (bits): 1024, 4096, 16384 for 1/2, 2/3, 4/5. 7136 for 7/8.Code rate: 1/2,
2/3, 4/5, 7/8.
Number of iterations depending on the bit rate. Capped at 4096.
On-the-fly configuration
CCSDS recommended synchronization word (default) or user set synchronization words
Other characteristics: see CCSDS 131.0-B-3
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