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SLS-CS_12-05 Some results on NGU coding schemes

SLS-CS_12-05 UnivPM-UniBO_NGU_Input.v2. SLS-CS_12-05 Some results on NGU coding schemes. Marco Baldi 1 , Marco Chiani 2 , Franco Chiaraluce 1 , Enrico Paolini 2 1 Università Politecnica delle Marche, Ancona, Italy { m.baldi , f.chiaraluce }@univpm.it

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SLS-CS_12-05 Some results on NGU coding schemes

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  1. SLS-CS_12-05 UnivPM-UniBO_NGU_Input.v2 SLS-CS_12-05Some results on NGUcoding schemes Marco Baldi1, Marco Chiani2, Franco Chiaraluce1, Enrico Paolini2 1 Università Politecnica delle Marche, Ancona, Italy {m.baldi, f.chiaraluce}@univpm.it 2 Università di Bologna, Bologna, Italy {marco.chiani, e.paolini}@unibo.it

  2. (128, 64) NASA binary LDPC code

  3. Max Iterations vs Performance

  4. Comparison with non-binary codes

  5. (256, 128) NASA binary LDPC code

  6. Max Iterations vs Performance

  7. Comparison with non-binary codes

  8. (512, 256) NASA binary LDPC code

  9. Max Iterations vs Performance

  10. Binary VS non-binary codes • Short non-binary LDPC codes outperform their binary counterparts by 1 dB or more • This appears to be independent of the maximum number of iterations allowed for decoding a received frame • The convergence speed (in terms of used iterations) of binary and non-binary codes is comparable • The parity-check matrices of the non-binary codes which have been used as a reference are the same used in: L. Costantini, B. Matuz, G. Liva, E. Paolini, M. Chiani, «Non-binary protograph low-density parity-check codes for space communications,» Int. J. of Satellite Communications and Networking, Vol. 30, No. 2, pp. 43–51, 2012

  11. Comments on TC Randomization • Ithasalreadybeenobserved [Alvarez2006] that, whenusedat high data-rates, the CCSDS standard TM randomizer incurs spurious problems • The problem is mainly due to Only Idle Data (OID) Frames, which are typically filled by zero bits before randomization • Depending on the mission requirements, some solutions have been studied to ensure suitable randomization of high rate data [Garello2009] [Alvarez2006] O. Alvarez and G. Lesthievent, “Pseudo-Random Codes for High Data Rate Telemetry: Analysis and New Proposal”, presented at CCSDS RF & Modulation & Channel Coding Working Groups, Rome, Italy, 12 June 2006. [Garello2009] R. Garello, M. Baldi, F. Chiaraluce, “Randomizer for High Data Rates”, European Space Agency Contract Report, March 2009, ESOC Contract No. 20959/07/D/MRP.

  12. Comments on TC Randomization (2) • At the Earth's surface, the power flux density (PFD) produced by spacecraft emissions must not exceed prefixed values, fixed by ITU and ECSS • These limits are those of interest for high data rate TM links • Concerning NGU links, transmission occurs from Earth to a spacecraft, or between two spacecrafts • What are the requirements to be considered for spurious frequencies (PFD masks, synchronization issues…)? • Idle frames in asynchronous uplink services?

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