1. Considerations for LDPC codes selection
SPACE LINK SERVICES CODING AND SYNCHRONIZATION WORKING GROUP
Montreal – Spring 2004
Considerations for LDPC codes selection
M. Chiani, G. Liva, E. Paolini
University of Bologna

2. Outline Consolidation of Requirements for New Channel Coding Schemes
Comparison of LDPC Coding Schemes: a Proposal for Benchmarking
Overview of solutions under investigation within CCSDS
CONCLUSIONS

3. I. Consolidation of Requirements for New Channel Coding Schemes

4. Consolidation of Requirements for New Channel Coding Schemes
SPACE MISSIONS
Non-Deep Space (Near-Earth)
Deep Space
Earth station-spacecraft distance > 2.0 x 106 km
Earth station-spacecraft distance < 2.0 x 106 km
CCSDS Mission Category B
CCSDS Mission Category A

5. Mission Scenarios Near Earth at Lagrange Point L2 Mars Missions
Low Earth Orbiter Payload Telemetry for Earth Observation
Low Earth Missions with High Rates

6. Near Earth at Lagrange Point L2
(e.g. ESA Missions: Darwin, Gaia, Herschel-Planck)
X Band at e.g. 10 Mbps
50 MHz available in total; No more than 10 MHz per mission
GMSK Modulation
Bandwith efficient codes required
BW>10MHz Ka (26 GHz or 37 GHz)

7. Mars Missions Similar to #1 but Deep Space 50 MHz available in X Band
Large BW Ka Band (32 GHz)
Constraints in Bandwidth and Link Budget to be evaluated
GMSK

8. Low Earth Orbiter Payload
Telemetry for Earth Observation
Critical problem in X Band: 0.35 GHz available band  8PSK TCM developed to this scope (CCSDS & ECSS approved)
Constraints mainly in Band occupation. Bandwidth is driver but code efficiency is important too.
Ka Band (26GHz) for future very high rate needs. 1.5 GHz wide. BW-eff to be considered from the outset.

9. TDRSS Case Not addressed by CCSDS so far. Should it be?
Alternatively,search for commonality?

10. Low Earth Missions with High Rates
Not for Earth Observation (e.g. successor of Hubble Telescope or Lunar Missions)
Same Band as #1
Likely to occupy the complete band
Not yet well defined  It may be wise to wait for Frequency Managers to fix strategy