Efficient Partial Parallel Encoders for IRA Codes in DVB-S2

DVB-S2 IRA Code를 위한 최적 부호화 방법

  • 황승오 (삼성전자 DMC 연구소 Multimedia 표준 그룹) ;
  • 이재용 (연세대학교 전기전자공학과 Ubinet LAB)
  • Received : 2010.08.24
  • Accepted : 2010.11.01
  • Published : 2010.11.30

Abstract

Low density parity check (LDPC) code, first introduced by Gallager and re-discovered by MacKay et al, has attracted researcher's interest mainly due to their performance and low decoding complexity. It was remarkable that the performance is very close to Shannon capacity limit under the assumption of having long codeword length and iterative decoder. However, comparing to turbo codes widely used in the current mobile communication, the encoding complexity of LDPC codes has been regarded as the drawback. This paper proposes a solution for DVB-S2 LDPC encoder to reduce the encoder latency. We use the fast IRA encoder that use the transformation of the parity check matrix into block-wise form and the partial parallel process to reduce the number of system clocks for the IRA code encoding. We compare the proposed encoder with the current DVB-S2 encoder to show that the performance of proposal is better than that of the current DVB-S2 encoder.

겔러거와 맥케이에 의해 처음 소개된 LDPC(Low density parity check)부호는 성능의 우수함 및 간단한 복호과정으로 많은 관심을 받아 왔으며, 특히 DVB-Satellite 2, DVB-Cable 2, DVB-Terrestrial 2 등의 차세대 방송시스템에서 널리 사용되고 있다. LDPC 부호의 성능은 충분히 긴 길이의 부호어와 iterative decoder를 사용함으로서 샤논의 한계에 거의 근접하는 성능을 보여준다. 그러나, LDPC 부호는 현재 이동통신에서 널리 사용되고 있는 Turbo 부호와 비교해서 복잡한 부호화 과정이 단점으로 지적되고 있다. 본 논문에서는 IRA 부호기를 사용하여 DVB-S2 LDPC 부호기의 성능을 향상 시킬 수 있는 방안을 제안한다.

Keywords

References

  1. R. G. Gallager, "Low-density parity-check codes," IRE Trans. Inform. Theory, Vol. IT-8, pp.21-28, Jan., 1962.
  2. D. J. C. MacKay and R. M. Neal, "Near Shannon limit performance of low-density parity-check codes," IEE Electron. Lett., Vol.32, pp.1645-1646, Aug., 1996.
  3. D. Divsalar, H. Jin, and R. J. McEliece, "Coding theorems for 'turbo-like' codes," in Proc. 36th Allerton Conf. on Communication, Control, and Computing, Allerton, Illinois, Sept., 1998, pp.201-210.
  4. T. Yokokawa, M. Nakane, and M. Kan, "A low complexity and programmable encoder architecture of the LDPC codes for DVB-S2,"in Proc. Turbo-Coding 2006, Munich, Germany, April, 2006.
  5. EN 302 307, Digital video broadcasting (DVB); Second generation framing structure, channel coding and modulation systems for broadcasting, interactive services, news gathering and other broad-band satellite applications, European Telecommunications Standards Institute (ETSI), 2003.
  6. M. Gomes, G. Falcao, A. Sengo, and M. Falcao, "High throughput encoder architecture for DVB-S2 LDPC-IRA codes," in Proc .IEEE International Conf. on Microelectronics (ICM), Cairo, Egypt, Dec., 2007, pp.271-274.
  7. S.O. Hwang, S.H. Muyng, H.J. Lee, S.I. Park and J.Y Lee "Partial Parallel Encoder for IRA codes", IET Electron. Lett., Vol.46, Issue 2, pp.135-137, Jan., 2010. https://doi.org/10.1049/el.2010.2896
  8. T. J. Richardson and R. L. Urbanke, "Efficient encoding of low-density parity-check codes," IEEE Trans. Inform .Theory, Vol.47, pp.638- 656, Feb., 2001. https://doi.org/10.1109/18.910579